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Niko3D
05-15-2015, 09:15 AM
Hello,

Has anyone ever had problems with Sun Light Dpont in animation?I don't know if it's a bug or it's just me.
I have a simple animation and I would like to show the sun's animation in differents hours. Exactly from 3am to 20pm.

So I put in "time" tab Time (decimal) 3 to 20, using compulsorily the Graph Editor, ok.
But when I launch "Bake Radiosity Scene" (like usual) it starts to calculate the radiosity but the radiosity doesn't work and it's like if GI is OFF.

Instead if I launch the "bake" with the scene already in light work like usual. I don't understand...128267128268
Also when the sun is below the horizon the model in the screen are completely white.

Any ideas why?It's quite strange for me...

Thank you
Nico

Niko3D
05-15-2015, 09:20 AM
...and with F9, radiosity works. It doesn't work only the Bake...it seems that the problem is the passage between completely night and day.

dpont
05-15-2015, 09:55 AM
...and with F9, radiosity works. It doesn't work only the Bake...it seems that the problem is the passage between completely night and day.

Both Daylight Sky Models are strictly working with positive sun angles,
nothing below the horizon.


Denis.

Niko3D
05-15-2015, 10:15 AM
Both Daylight Sky Models are strictly working with positive sun angles,
nothing below the horizon.


Denis.

Hi,
thank you for reply me.
So...I can't use SK SunLight for to have this effect...in any case I don't understand why the radiosity doesn't work.
Sorry for the question...But if the light doesn't work below the horizon, so it works only in a day, why can I select any time?

Thank you!
Nico

dpont
05-15-2015, 11:15 AM
Can't say for your issue with radiosity,
this is related to your GI settings,
not to Sunsky itself.


Time is only one element beside day, month etc
for calculating sun position, no way for disabling
it before the process.

Denis.

prometheus
05-15-2015, 12:48 PM
Can't say for your issue with radiosity,
this is related to your GI settings,
not to Sunsky itself.


Time is only one element beside day, month etc
for calculating sun position, no way for disabling
it before the process.

Denis.

Thanks for the dp sunsky stuff, if you have time you can check some of my sessions with your sunsky model and hypervoxels and fog etc.
You seem to have released a new update a few days ago? whatīs new in those?

Still wish there was some kind of fog model that works a bit like use backdrop color, but with true z-depth, neither lightwaveīs realistic fog or the sunsky_atmosphere plugin can handle that you always got a sharp edge between background distance and the sky, the only way to fake it seem to be using backdrop color if you also have sunsky environment on, but that will only overlay the sunsky on top of front objects, so the sharp edge/matte in the environment plugin (where sky meets ground) will always show as
a sharp line, and the sundisc will always be in front....I know this isnīt how one should use it with backdrop fog color that is...would have wished for a trick solution but canīt find any good option that works with vpr in realtime feedback.

dpont
05-16-2015, 01:42 AM
... so the sharp edge/matte in the environment plugin (where sky meets ground) will always show as
a sharp line, and the sundisc will always be in front...

I don't know your exact settings,
Sunsky Environment is not able to detect Fog BackDrop for filtering Sun disk,
speaking of Sunsky,
about the horizon edge,
I can see one, but only in the Hosek model,
do you get it with Preetham?

Denis.

prometheus
05-16-2015, 09:42 AM
I don't know your exact settings,
Sunsky Environment is not able to detect Fog BackDrop for filtering Sun disk,
speaking of Sunsky,
about the horizon edge,
I can see one, but only in the Hosek model,
do you get it with Preetham?

Denis.

I will post scene samples up here to showcase it in some various ways.

I think you might have a point about the Hosec model VS Preetham, Ivé noticed that before,one of them seems better, have to recheck.

Thanks.

Michael

dpont
05-16-2015, 10:31 AM
Sunsky Environment is not able to detect Fog BackDrop for filtering Sun disk...

I didn't test this but,
the Sun Disk Diameter isn't a global parameter,
so you may set it to zero in a Sunsky Texture Layer of LW fog,
while it is still set to 0.52° in Background Sunsky Environment.

Denis.

dpont
05-16-2015, 10:44 AM
about the horizon edge,
I can see one, but only in the Hosek model,
do you get it with Preetham?...

128279

Left, classic Edge effect,
Right, experimental Mirror effect, but darker in Nadir direction,
also a few degrees are skipped near the horizon,
this remove the green line in Hosek,
this way it could be possible also to fake sky illlumination
when sun is below the horizon.

Denis.

shrox
05-16-2015, 11:52 AM
128279

Left, classic Edge effect,
Right, experimental Mirror effect, but darker in Nadir direction,
also a few degrees are skipped near the horizon,
this remove the green line in Hosek,
this way it could be possible also to fake sky illlumination
when sun is below the horizon.

Denis.

Thanks for all work work and interest! I appreciate it.

prometheus
05-16-2015, 06:05 PM
128279

Left, classic Edge effect,
Right, experimental Mirror effect, but darker in Nadir direction,
also a few degrees are skipped near the horizon,
this remove the green line in Hosek,
this way it could be possible also to fake sky illlumination
when sun is below the horizon.

Denis.


Interesting..it could work nicely.
have to check this tomorrow, need to crawl in to my coffin...before the real sun shows up :)

I do notice the hard ege in both modes though...but that is when you look at the edge overlay on objects, if you set a maximum distance very high, that will go away..but so will the effect of the fog on nearby objects, so that isnīt good.
the preetham is even worse, since that goes from sky to black, hosek blends in better I think.
will try a bit more with sunsky texture layer of lw fog....was messing a bit before with trying to overcome the issues that way, but forgot to test turning off the sun disk that way.

If you got that experimental mode working, that would be nice...sort of a little what I was looking for, I think.

Edit... a fast check with using fog color texture and sunky in there, setting to world coordinates..ok..and it looks ok on the foreground objects without any sharp edges...however, it has the same issues of lacking proper zdepth it seems..even though the object seems covered with fog, the outline edges of the object is sharp and not faded as they would in fog and as they do when using backdrop color.
you can not use both fog color texture and backdrop color as fog only one at a time works.


Cheers..will post samples tomorrow.

dpont
05-17-2015, 12:01 AM
...If you got that experimental mode working, that would be nice...sort of a little what I was looking for, I think.

Hope so but not fully integrated yet.



...however, it has the same issues of lacking proper zdepth it seems..even though the object seems covered with fog, the outline edges of the object is sharp and not faded as they would in fog and as they do when using backdrop color.
you can not use both fog color texture and backdrop color as fog only one at a time works...

This has to do with the Fog effect, a faking effect,
blending backdrop with foreground isn't sufficient
for simulating the fog, especially in front of the Sun,
doubled by optical lens specificities,
in such case, post-processing separate layers
gives a better control.


Denis.

prometheus
05-17-2015, 07:18 AM
Hope so but not fully integrated yet.




This has to do with the Fog effect, a faking effect,
blending backdrop with foreground isn't sufficient
for simulating the fog, especially in front of the Sun,
doubled by optical lens specificities,
in such case, post-processing separate layers
gives a better control.


Denis.

yes..that is what I thought, so may be it, I would really love to have the option to control it directly in the scene, thatīs a part of getting the mood as you want it without having to go post, if you do it in post you can not control lighting in interactive process with the fog, and it is therefore impossible to find that "right moment" in real time..with post that process takes a lot longer to arrive to the right moment, when you move the sun location and the light affects the fog in the right position, thatīs when you know you have found the right spot, that is impossible to do with post processing in the same way.

Thatīs why vueīs Real volumetric fog and atmosphere system is so damn nice when getting it all right directly when tweaking.
wish there were such fog system in Lightwave, without the horrendous ray marching slowdown, the ground fog with ray marching...I canīt use, not even with VPR...so slow.

Maybe a hybrid workflow with backdrop turned on,..and tweak it till the light and fog conditions looks nice... then turn it of and use fog color texture with sunsky and then render out passes and fix it in post.

dpont
05-17-2015, 08:12 AM
Left, classic Edge effect,
Right, experimental Mirror effect, but darker in Nadir direction,
also a few degrees are skipped near the horizon,
this remove the green line in Hosek,
this way it could be possible also to fake sky illlumination
when sun is below the horizon...

128289

I updated the windows versions of Sunsky,
with this new "Ground Mirror" option,
so this extends the sky model below the horizon
in a smoother way, optimized for sunrise and sunset
and for backdrop fog,
(even if this not fixes all the problems).

here an animated sunset,
128288

Denis.

prometheus
05-17-2015, 10:18 AM
128289

I updated the windows versions of Sunsky,
with this new "Ground Mirror" option,
so this extends the sky model below the horizon
in a smoother way, optimized for sunrise and sunset
and for backdrop fog,
(even if this not fixes all the problems).

here an animated sunset,
128288

Denis.


Thanks Denis thatīs great...itīs not perfect but helps in some cases and to soften up the ground edge which otherwise show such hard edge when used with fog color "use backdrop"
Still remains the problem of the sundisc overlaying on top of objects if you would like to use backdrop fog color I think, and using sunsky in fog color texture, that brings back the issue of the object not fading in to the fog and show sharp edges on objects.

Might be a work around somewhere, maybe exclude the sundisc in the sunsky, and add it somewhere else?

A suggestion, the sunsky motion modifier, would it be a good idea to have a checkbox called "use Earth radius" which sets the distance to be true to that (6 371 km), for those not knowing how to set it up? and if it is setup to have it checked by default, it will be correct the very first time you apply it without doing additional changes.

hereīs an image showcasing the new blending mode you updated, which is clearly much better in the lower image in mirror mode, itīs a hack, but it definitly helps.



http://forums.newtek.com/attachment.php?attachmentid=128290&d=1431879429

Niko3D
05-18-2015, 03:11 AM
Can't say for your issue with radiosity,
this is related to your GI settings,
not to Sunsky itself.


Time is only one element beside day, month etc
for calculating sun position, no way for disabling
it before the process.

Denis.
This is very strange...
My GI settings are the same...and I made and I'm making a lot of animations without any problems.
But...actually it's the first time that I put the Sun under the horizon. It seems that if the bakeGI starts with the sun under the horizon the Timing of SunSky Light is ignored by GI.
I'll make some another test with another scene...
In any case thank for your wonderful work!:)

Niko3D
05-18-2015, 03:27 AM
I put a TestScene...128304128305

dpont
05-18-2015, 04:03 AM
This is very strange...
My GI settings are the same...and I made and I'm making a lot of animations without any problems.
But...actually it's the first time that I put the Sun under the horizon. It seems that if the bakeGI starts with the sun under the horizon the Timing of SunSky Light is ignored by GI..

Confirmed, I would say the timing of the environment sky is ignored
when we bake the scene for radiosity,
you could report it to LW3DG with this sample scene.

However it seems that works with no GI interpolation.

Denis.

Niko3D
05-18-2015, 04:54 AM
Confirmed, I would say the timing of the environment sky is ignored
when we bake the scene for radiosity,
you could report it to LW3DG with this sample scene.

However it seems that works with not GI interpolation.

Denis.

Yes of course, I'll report to LW3DG...;)
Thanks Denis!...

Niko3D
05-19-2015, 09:32 AM
Hi,

I wrote to LW3DG and they actually found something strange in this case. So they forward the "issue" to the developers.

Thank you

Chrusion
05-19-2015, 02:41 PM
What's the best way to incorporate a cloudy sky image into SunSky, such that the image sky and clouds interact with the SunSky generated backdrop colors?

Yep, I understand the cloud lighting will not change, but just wonder how to get some clouds in there.

Any procedural cloud plugins that would interact with SunSky? Played with SkyTracer way back when, but never liked the flat, pancake clouds.

Chrusion
05-20-2015, 10:47 AM
How do we fade/hide the sun disc behind a mountain range mesh?

I know that SunSky self-fades at around 10 degrees below the horizon, but my mountains rise above the horizon 15 degrees and has a radius of 800 m (200 m short of the 1km distance of the Sun), so the disc of the sun renders over top of the mesh.

Also, I've pretty much answered my previous cloud image integration question by applying four gradients to the luminosity, diffuse, translucency, and additive trans. scalars of the image mapped sky dome surface, driven by the pitch angle of the Sun Light. Each gradient is slightly different such that, for example, when the sun is at it zenith, luminosity = 100%, diff, translucency, and add trans = 0%. They ramp/fade as the sun gets closer to the horizon such that add trans = 80%, which blends the image with the SunSky background colors, while diff and translucency ramp up as luminosity fades to 0% to maintain an overall balanced blend with the backdrop and atmospheric fog.

dpont
05-20-2015, 11:06 AM
How do we fade/hide the sun disc behind a mountain range mesh?

I know that SunSky self-fades at around 10 degrees below the horizon, but my mountains rise above the horizon 15 degrees and has a radius of 800 m (200 m short of the 1km distance of the Sun), so the disc of the sun renders over top of the mesh...

In rendered image the Sun disk is drawn in background with the Environment or Texture Sky,
so it can't be over an object or your mountain,
except with LW Fog and Backdrop Color option,
the 1km distance (from Sun Light panel)
is used for OpenGL preview.

Denis.

prometheus
05-20-2015, 11:46 AM
What's the best way to incorporate a cloudy sky image into SunSky, such that the image sky and clouds interact with the SunSky generated backdrop colors?

Yep, I understand the cloud lighting will not change, but just wonder how to get some clouds in there.

Any procedural cloud plugins that would interact with SunSky? Played with SkyTracer way back when, but never liked the flat, pancake clouds.


you could use textured environment together with sunsky, add the image map in there, try some different blending modes like multiply etc...depends what your image format is, and if you have transparent background and alpha etc so only the clouds are visible, you should also consider using additional layer above that one set to alpha, and use the pitch and correct the influence.

May have to set this up for display here later...

otherwise..if you can handle the rendertimes, I prefer throwing in hypervoxels....



https://vimeo.com/127434660



Regarding sun, the sundisc is no worry, it will hide behind objects, I often use realistic fog..and set it to backdrop color, and that poses a problem with the sun disc being overlayed on top of everthing since it isnīt supposed to be used that way really...but otherwise it should work as it should.


if you want to have a sun lensflare, just activate the lensflare on the sunsky_sunlight, but as soon as you do, you notice that the lensflare is located differently than your sun, to fix this...you go to the lights motion panel and add the sk_sun motion modifier, not sunspot.

and preferably you set it to the earth radius 6 371 km in the distance tab to match up properly with the sunsky_sunlight location, also in the lights lenflare panel, set it to hide behind objects and maybe also fade behind objects, then lens flare should hide and fade behind terrain ..even in VPR, there are some sligth differences here between VPR and final render though.

Skytracer? drop it...no good use since it can not cast ray shadows from clouds, nor can you go above clouds, and they do not look as good as hvīs...skytracer is in fact quite slow in some cases too, and it donīt have the same nice realism in air properties as dponts_ sunsky.

Edited, you could also us cloud plane..simple polyīs or use a very large sphere dome for clouds with transparency, and also set the color and luminosity channels on that with envelope modifier sk_suncolor, that might give some color and luminosity tinting to cloud maps based on the sunsky_sunlight pitch/angle

prometheus
05-20-2015, 01:05 PM
On second thoughts, I would as no 1 after hypervoxels probably throw in a huge poly plate, and set transparency to 100, throw in a good cloud map as seen from above or spherical maybe, then set cloud map layer to alph, copy the layer and paste to luminosity and change mode to additive, perhaps correct with some gradients above that, and you could of course try node surfacing for it to..this cloud texture plane is casting raytraced shadows nicely on the ground, move plane up and down to get it right in altitude, render superfast.

The trick would be to get color and some depth thickness to it, the colors can be done with entering the envelope color channel of the cloud surface and add the sk suncolor modifier on each seperate value for r.g.b

Chrusion
05-20-2015, 02:58 PM
For some reason, the Environment SunSky plugin's properties are being cropped off at the bottom. I reloaded the scene, to no avail. I remember accessing the Sky and Sun Tabs when first setting it up, but now they are cut off by the Effect Panel's bottom border.

I tried removing and readding the plug to no avail.

prometheus
05-20-2015, 03:06 PM
For some reason, the Environment SunSky plugin's properties are being cropped off at the bottom. I reloaded the scene, to no avail. I remember accessing the Sky and Sun Tabs when first setting it up, but now they are cut off by the Effect Panel's bottom border.

I tried removing and readding the plug to no avail.


You mean like this? I also have this issue, try closing the effects panel, and reopen it, in my case the sunsky panel then opens in a single fresh window, not stuck within the effects panel properties,
I think dpont need to check that, or the lw team do something about their window popup system.




http://forums.newtek.com/attachment.php?attachmentid=128323&d=1432155952

spherical
05-20-2015, 03:35 PM
I've had that issue with a couple of tools. Can't recall exactly which just now, but LWCAD seems to pop to mind; although it loads into the Numeric panel which is resizable. It'll come to me when I'm not thinking about it.

Chrusion
05-21-2015, 06:39 AM
You mean like this? Yep. Didn't think about closing Effects panel. Strange that SunSky pops open immediately when clicking on the Background tab. Thanks.


...set it to backdrop color, and that poses a problem with the sun disc being overlayed on top of everything since it isnīt supposed to be used that way...Hmmm... that's the only way (fog -> use backdrop color) I can get the mesh to blend correctly with the sky. Adding Sunsky Atmospheric volumetric doesn't produce any where near the level of fog (atmospheric perspective -> detail fade with distance, haze colorization, etc) the way Use Backdrop Color does. I can't get it to wash out the detail (bumps, color map) with distance, instead it just changes the "exposure" and tint of the mesh. What good is Sunsky Environment if Use Backdrop Color can't be used to colorize meshes when the sun is below the mesh? Using native fog's single, non-changing color is worthless when using Sunsky's animatable Time param to do "time lapse" sunrise/set anims.

I betcha Denis could add new params to make the disc fade behind geometry when Use Backdrop Color is enabled. He's a very intelligent fella... boggles my mind.

In addition, there is a highly undesired artifact of SK Sun Light when the light goes below flat portions of a mesh with high-amplitude procedural/image bump maps. Even though the mesh is in shadow, the bumps are still being illuminated (see image). This creates a "pop" when the light goes from negative pitch to positive... that is, from shadowed to illuminated, however oblique that is... even a fraction of a degree above 0. IOW, the mesh goes from the bump illumination in the pix below to NO bump illumination on the next frame due to the very oblique angle of the sun to the mesh as the light crosses Y=0.

dpont
05-21-2015, 08:17 AM
The cropped panel is an issue of XPanel in Layout,
nothing to do in the plugin.

The Sun Light is still illuminating below the horizon as it should
for a smoother fading effect (an improvement in last version),
it is possible to fade it, sooner or later, with Light Intensity envelope.

Sunsky as Background (Enviro or Texture) isn't able to detect
if it is used for pure background, fog or anything else.

Don't know if you can mix HV clouds with a Skydome with your scenes,
while Fog Backdrop uses Sunsky Environment without SunDisk (0° Diameter)
you can still get it in the Sunsky Texture of a Skydome.

Denis.

prometheus
05-21-2015, 09:06 AM
The panel cropped is an issue of XPanel in Layout,
nothing to do in the plugin.

The Sun Light is still illuminating below the horizon as it should
for a smoother fading effect (an improvement in last version),
it is possible to fade it, sooner or later, with Light Intensity envelope.

Sunsky as Background (Enviro or Texture) isn't able to detect
if it is used for pure background, fog or anything else.

Don't know if you can mix HV clouds with a Skydome with your scenes,
while Fog Backdrop use Sunsky Environment without SunDisk (0° Diameter)
you can still get it in the Sunsky Texture of a Skydome.

Denis.


I thought so...about the issues with the panel, I might need to alert the lw team if they havenīt noticed already and see if they are keen on solving it.

About the other issues, yes I can use hypervoxels and mix with a skydome, no problems there if you just turn off cast shadows in the surface panel. itīs probably the solution to go for... if one would like to also use the fog and use backdrop color with the sunsky environment, that way I can turn of the sun radius in the sunsky environment, but have the sundisc active so to speak in the surface of the skydome.
So that is one way to get around the issue of the sun disc being overlayed on top of foreground objects, but still having the option to use backdrop color in fog settings that blends so nicely with the rest of the environment.

A skydome radius of 6731km might be proper, and one should turn of cast shadow, receive shadow and self shadow in the skydomes render properties, make sure the dome is double sided or flipped with normals inwards to the scene.
sunsky is applied in the color channel and the luminosity is set to 100, that should do it.


Cheers Denis

Michael

prometheus
05-21-2015, 10:42 AM
Yup..I think the route I will work with from now on, that would be to use sunsky on both a skydome and for fog blending sunsky environment with backdrop color, most stuff seem to be working nicely with that..sun is not showing up on top of objects, and it will be obscured when hypervoxels clouds are blocking the sun, and at the same time I can get that nice fog fading and blending in the horizon and also fading terrain or objects so they do not have sharp edges, all directly in VPR with interactive tweaking.

It takes a bit of work to set up though, and to get clouds to be lit nicely I might share some tips on how to do that with sunsky later on, it takes a couple of envelope channels in both the light color and hypervoxels to get a nice realistic look according to how the sun is located.

I also noticed that using sunsky in a skydome gives an actual radiance sun intensity falloff, that one do not get with sunsky in the environment tab..so for me it looks more realistic with a skydome than sunsky environment only.

dpont
05-21-2015, 11:33 AM
...I also noticed that using sunsky in a skydome gives an actual radiance sun intensity falloff...

If you speak about the 'Aerosol' parameter in Sun tab panel,
it is used only in Preetham Sky Model not in Hosek,
should be disabled in Texture like it is in Environment,
will fix this later.

Denis.

prometheus
05-21-2015, 12:16 PM
If you speak about the 'Aerosol' parameter in Sun tab panel,
it is used only in Preetham Sky Model not in Hosek,
should be disabled in Texture like it is in Environment,
will fix this later.

Denis.

No..not sure it is it, You could be right...but I will get back to that and check tomorrow..to busy making clouds now, and a few minutes more then bedtime.


Thanks Denis for checking in and solving issues , It sure has helped push the sunsky plugin a bit more and also helped to find the best way to combine all the stuff, images and perhaps some youtube voiceless sessions may come up tomorrow or saturday.

prometheus
05-21-2015, 01:15 PM
Yep. Didn't think about closing Effects panel. Strange that SunSky pops open immediately when clicking on the Background tab. Thanks.

Hmmm... that's the only way (fog -> use backdrop color) I can get the mesh to blend correctly with the sky. Adding Sunsky Atmospheric volumetric doesn't produce any where near the level of fog (atmospheric perspective -> detail fade with distance, haze colorization, etc) the way Use Backdrop Color does. I can't get it to wash out the detail (bumps, color map) with distance, instead it just changes the "exposure" and tint of the mesh. What good is Sunsky Environment if Use Backdrop Color can't be used to colorize meshes when the sun is below the mesh? Using native fog's single, non-changing color is worthless when using Sunsky's animatable Time param to do "time lapse" sunrise/set anims.

I betcha Denis could add new params to make the disc fade behind geometry when Use Backdrop Color is enabled. He's a very intelligent fella... boggles my mind.

In addition, there is a highly undesired artifact of SK Sun Light when the light goes below flat portions of a mesh with high-amplitude procedural/image bump maps. Even though the mesh is in shadow, the bumps are still being illuminated (see image). This creates a "pop" when the light goes from negative pitch to positive... that is, from shadowed to illuminated, however oblique that is... even a fraction of a degree above 0. IOW, the mesh goes from the bump illumination in the pix below to NO bump illumination on the next frame due to the very oblique angle of the sun to the mesh as the light crosses Y=0.


Not sure if you have follow the recent posts, but we/me kind of have found a workaround, as I mentioned in my latest post, use sunsky on a large skydom instead, but together with sunsky environment and backdrop color, then you turn of the sun disc size in sunsky environment, that will not affect the sunsky disc in the skydomeīs sunsky texture, so that way we can both use the backrop fog color and without the sundisc visible on top of geometry or in front of hv clouds, the sun disc will show up in the skydome properly, of course, if you have much fog the sun disc will actually fade away in that.
..Edit...the bump issue I havenīt taken a look at...will do later.

I will show samples this weekend.

Chrusion
05-22-2015, 09:45 AM
if you want to have a sun lensflare, just activate the lensflare on the sunsky_sunlight, but as soon as you do, you notice that the lensflare is located differently than your sun, to fix this...you go to the lights motion panel and add the sk_sun motion modifier... set it to the earth radius 6 371 km in the distance tab to match up properly with the sunsky_sunlight location Hmmm... not working, Denis. The flare is still offset about 7 degrees below the disc (which is being drawn using the Sunsky procedural texture on a sky dome). Changing the motion modifier distance to 200m obviously brings the flare towards the origin, and setting it to 6 million meters doesn't really change the parallax vs. 6.371 Km, so... not sure what to do next.

This begs the question... why can't Sunsky be made to render the disc ON the light? I mean, the icon view shows the light exactly where the flare is and the dashed red line goes from the origin to the flare, so why can't the disc be placed there as well?

Chrusion
05-22-2015, 09:57 AM
...use sunsky on a large skydom instead, but together with sunsky environment and backdrop color, then you turn off the sun disc size in sunsky environment, that will not affect the sunsky disc in the skydomeīs sunsky texture, so that way we can both use the backrop fog color and without the sundisc visible on top of geometry...Yes. THANK YOU for that! Works great. I'm blending Sunsky texture with my HDR cloud map (placed above with blend = additive) and using the node tree posted previously to ramp up Luminosity of the surface as the sun rises/sets, so that the scene goes completely dark when the sun is like an hour or so below the horizon. Then tweaked SK Atmosphere to get the distant mountain fog to match with the SK backdrop.

Changing the sun disc from backdrop rendering to skydome surface rendering fixed the illumination of the bumps on the bump mapped terrain when the sun crossed under the horizon. Don't know why, but I'm happy.

prometheus
05-22-2015, 03:05 PM
Hmmm... not working, Denis. The flare is still offset about 7 degrees below the disc (which is being drawn using the Sunsky procedural texture on a sky dome). Changing the motion modifier distance to 200m obviously brings the flare towards the origin, and setting it to 6 million meters doesn't really change the parallax vs. 6.371 Km, so... not sure what to do next.

This begs the question... why can't Sunsky be made to render the disc ON the light? I mean, the icon view shows the light exactly where the flare is and the dashed red line goes from the origin to the flare, so why can't the disc be placed there as well?



will have to take a look at the sunsky modifier again and see whatīs happening, in sunsky environment only I thought it aligned pretty well, with a skydome itīs not as accurate it seems when matching lensflare with the sundisc.


a tip...if you throw in hypervoxels...also try fill the skydome with a procedural like weather, to simulate higher soft whisp clouds, that helps fill in to the general sky atmosphere, rarely there is only just one cloud altitude layer





http://forums.newtek.com/attachment.php?attachmentid=128342&d=1432328672

Chrusion
05-22-2015, 07:46 PM
Lovely terrain mesh, Prom! Wow! What are you using to generate it? HV clouds are very nice as well.

I'm running a render of my low-rez mountain terrain, going from sunrise to about 11 am over 15 seconds and discovered that the sun disc doesn't match the light rays either, and it just now dawned (pun) on me why... the radius of my sky dome is only 800 m (V-8 face-palm)... duh. Aborting the render and scaling up the objects so radii are 6.4 km. Silly me.

Doing this via remote desktop... wee.

dpont
05-23-2015, 12:11 AM
... and discovered that the sun disc doesn't match the light rays either, and it just now dawned (pun) on me why... the radius of my sky dome is only 800 m (V-8 face-palm)... duh. Aborting the render and scaling up the objects so radii are 6.4 km...

Don't know what you are doing exactly,
that's what also I don't recommend or preset
sun position, these are settings for secondary effects,
and there are a lot of possible user variations,
so Sunsky behavior is accurate for its current
sky/sun background and lighting effect,
but others need adjustments from your own.

Sun LW Distant Type works with and heading and pitch angle exclusively
Sun position modifier for render or Sun distance preview
have different main purpose, render for aligning LW flare,
ogl drawn preview for helping approximatively the scene setup
with sky/sun settings,
Sky Models work with sun angles exclusively,
projected on a spherical background, always centered
at the point of view,
when working with a Skydome object , 'Manual' mode for Sun,
and with a moving camera, not strictly centered,
you may derives all the sky and sun alignments,
basically a greater size for skydome, matching sun distance
with skydome radius,
another tip is to parent the position of the skydome to
the camera (position only).

Denis.

prometheus
05-23-2015, 05:26 AM
Lovely terrain mesh, Prom! Wow! What are you using to generate it? HV clouds are very nice as well.

I'm running a render of my low-rez mountain terrain, going from sunrise to about 11 am over 15 seconds and discovered that the sun disc doesn't match the light rays either, and it just now dawned (pun) on me why... the radius of my sky dome is only 800 m (V-8 face-palm)... duh. Aborting the render and scaling up the objects so radii are 6.4 km. Silly me.

Doing this via remote desktop... wee.



My skydome, I simply created a sphere with 6731km in radius.

The terrain, used worldmachine, quite a quick setup in world machine, without actual intention to do any good work, so there is plenty of room to make much much better terrain...there is no real texturing going on either.
image map was 2049x2049, stuff under that tends to look to lowres and too smooth, I also often just crank up the subpatch level so I may be able to use surfaces without smoothing on, smoothing interpolates the terrain too much and thus you get unrealistic
terrain.

In this case it was rendered out at over 3 millions of polygons at rendertime, 6 to 8 millions might enhance it a bit more.
I also use a the dots procedural as alpha layer on top of the image map in the displacements, and auto size it and then correct the fuzzy edge, that way I can get non zero edges on the terrain object, and with that you can also instance the terrain on larger flatter ground to have tiled multi terrain, I didnīt do that here though..merely to avoid problems with terrain displacements clipping in front of the camera.

render time was 5minutes 19 seconds min1 and max 9 samples, lightsamples was 5 to make sure avoid grain in the shadows, and with a lot of firefox browsers open and with photoshop and after effects open, so it may be possible to render a little faster.

If I were to render it out more properly, I would also render out the voxels in very good quality, this was only medium.
the hvīs...I could lower the ambient light for voxels, the ambientl light can be nice to light clouds with a sort of fake global illumination, it getīs more real in terms of lighting by that, but it also makes the voxels more detailed and appearant around each particle and itīs density, and in real clouds there are no such things as particles setting the volume density, since cloud volumes should be more based on the actual cloud volume, if I turn of ambient lighting, I could get a much smoother look overall..but it also becomes a little too dark..so that is something I need to find the best balance on.

So textured volume cloud layers has advantages over particles, it could probably look better thouigh if the lw team fix the blending mode.

I think there might be a problem with my scene though, I didnīt follow the real scale properly when setting it up, the clouds and terrain are probably enormously much bigger that real life counterpart, so throwing in a very large spaceship, well it will probably be so tiny and hard to notice...depending on size of course.
should have rescaled terrain and cloudsize to more realistic scales.

Chrusion
05-23-2015, 06:53 AM
Could you share the scene with only the HV clouds? Or tell us the way you emitted particles and settings for HVs.

prometheus
05-23-2015, 07:17 AM
Could you share the scene with only the HV clouds? Or tell us the way you emitted particles and settings for HVs.

Thatīs my very hard work to get right through many many hours, so I am not keen on providing just that element as free, I have described how to work on it in many various threads and shared some settings here and there, and some showcases on youtube.

so I think I have covered the principles in all those threads, including this one and the one in lightwave tips and tricks section.

emitting particles , nothing special here, you just need a particle emitter, set to frame and emitt the "right" amount of particles in relation to how large the particle size is, itīs a balance depening on the look of the clouds..there are some things that are important.
This sample was a particle emitter set to box nozzle and frame birth rate, 1000 and equally limit it to 1000 particles.
the size of the emitter x 12 Miles 6 meter z 12 miles...thatīs pretty much it for the emitter, sometimes I use a texture in the birth rate to "shape" gather the particles in clusters based on a procedural, in this sample I didnīt so the particle distribution is only uniform.

Then thereīs the hypervoxels, I mostly use beer or rayleigh, in this case rayleigh, only one light affecting it 4%, small amount of ambient light, and the ambient color I actually used an envelope with the sun color modifier., so the ambient light tintīs the voxels differently depending on how the sun pitch is.

I usally stretch the voxels on y axis 40% and sometimes I use maintain volume...that donīt work so good in animation though..only still.

The particle size is huge...200 km and a size variation at 460%...this is Very important to make the cloud size with variations.
to soften clouds..I always use a local distance gradient in the dissolve channel..from white to black, on top of that gradient I add another one with distance to camera, that helps fade the cloud out at distance.
I used turbulence hypertexture, and here is the trick...turbulence alone do not give enough secondary undulations, that is why I use a hypertexture effect, in this case the displacement, but you have to understand the ratio between effect speed and the size of the clouds, since the clouds particle size is so huge, I had to use 0.0005 % to get the right scale displacement, and if I had the particle size smaller, I could decrease the decimals, that is what I just have to find out during the process.

Texture amplitude at 400% how much volume or hypertexture cut in to the particle volume, is also dependent on the actual hypertextures contrast as well as how much density I have..sometimes I increase density to 260 and over that depending on the look I want.
thickness at 27% and the same amount of smoothness, shadow strength at 2% this one is important to balance depending on density and opacity set, only volume shadows ..no texture shadows.



I also used a near clip distance at 800 km, so it is cleared in front of the camera and it also helps avoid long rendertimes because of volumes to close to camera, altitude of the cloud layer was in this case set to 555 km...by now you see that I have
gone way to far in relation to Real world scale, at least for this scene...my struggle later would be if i would want to rescale to more correct world size later on.

To get succesfull with hv clouds, it takes hours and hours to work with it, from that you learn how each settings affect other settings and what you have to do to balance those in relation to the each other, another thing you have to do...go out and spend time looking at clouds.

Note...the displacement mode for additional "displace/advection" will probably not work so nicely with animated clouds.

I just gave away almost all of the settings..now you have to find a way of getting it right by doing the work yourself:D and you can also even learn from it by doing the setup yourself

Without the introduction and the speed of VPR, I would never have attempted to work with these kind of stuff, but with VPR..some of that stuff is even faster than the ozone plugin from eon...which I by the way donīt have 1/4 the size of full viewport to tweak on.
and itīs own internal previewer is way slower than the VPR iterative update of hypervoxels.

prometheus
05-23-2015, 07:37 AM
I must add...if you got time and passion and an eye for cloudscapes, donīt let the initial process of working with hypervoxels scare you away, setting up hypervoxels and particles to form clouds..well..it isnīt easy going and it will just look like crap when you start with it, so it does for me too....but after tweaks and tweaks it will most certainly improve both in relation of how often you do it, and in terms of when working with the actual scene elements as you progressivly set up and tweak the elements.

What could be considered questionable in terms of working with hv clouds, that is foremost the look of animated clouds and render speed, and perhaps the blending smoothness of the overall cloud volume when used with particles...some of that can be improved when the team decides to improve on voxels...especially the blending mode but also the edge smoothness and perhaps introduce mie scattering with a boost control that can be set with a slider value.
There are stuff I havenīt tried that much on particle voxels yet though, such as flattening clouds instead of stretching, and to do it with dpont boolean nodes.

bobakabob
05-26-2015, 03:58 AM
Thanks for sharing folks. Applying transparency alpha on a skydome to just display textured wispy clouds results in VPR slowing down significantly. What am I doing wrong?

lardbros
05-26-2015, 04:21 AM
Thanks for sharing folks. Applying transparency alpha on a skydome to just display textured wispy clouds results in VPR slowing down significantly. What am I doing wrong?

Using transparency to 'cull' the bits of the sky you don't want showing, means that the renderer still traces through every single point on the mesh, even if it's not visible.

Try using a black and white clip map on the dome instead, and see how that goes. Clip maps effectively 'cull' the invisible polys/mesh so they don't slow the rendering down as much as a transparency.

prometheus
05-26-2015, 06:43 AM
Thanks for sharing folks. Applying transparency alpha on a skydome to just display textured wispy clouds results in VPR slowing down significantly. What am I doing wrong?

Will have to take a look, in my image however, I used a procedural directly on the skydome for the secondary softer cloud layer ..since I donīt need them to cast any shadows at those hightīs, if you donīt plan on using the cloud plane layer as a shadow caster, you might be able to turn of some things that slow down..but I canīt recall getting VPR slowing down significantly.
will have to check again later.

are you using nodes?

bobakabob
05-26-2015, 07:01 AM
Thanks both, Prom are you using procedurals on Sunsky itself, I didn't realise it was possible. Or do you mean the skydome you've created yourself? Clip maps only work with black and white values, but definitely worth a go.

prometheus
05-26-2015, 07:44 AM
Thanks both, Prom are you using procedurals on Sunsky itself, I didn't realise it was possible. Or do you mean the skydome you've created yourself? Clip maps only work with black and white values, but definitely worth a go.

nope..not on sunsky itself, it contains no layers for procedurals, you can however add procedurals by adding a textured environment above the sunsky environment, that I have tried before, but not this time, this time I added it on the skydome as you also thought, not sure which blending mode I used, probably additive and above the sunsky layer.

there is the skydome which is setup with the sunsky procedural in color channel and 100% luminosity, and the weather procedural above that in the same color channel.

but to make use of the nice backdrop color fog, I use sunsky environment..but I turn off the sundisc in the sunsky environment and I control the sun only in the skydomeīs sunsky procedural color channel.
The new mirror mode Denis created helps blend the fog better with front objects, so we donīt get such a hard edge.

And the main clouds are of course hypervoxels on particle fields.

I just checked som cloud planes and transparencey, I donīt perceive it as slowing down, I also tested with nodes, which I might start to use, got some interesting shading along with the option to set a color envelope for the texture, which you can not do in standard layer, so when I rotate the sun, the color changes on the cloud plane texture too, since I add the suncolor plugin in each one of the three color layers.

prometheus
05-26-2015, 12:04 PM
I got some quite nice softer clouds on cloud planes, will post later...but it picks up the sun color quite nice and I got a good procedural going on with the weather procedural and then feeding turbulence procedural in to cloud offset and also in to cloud gain.
this all done within nodes almost, except I couldnīt get color to work in nodes when I add an envelope and use the sun color modifier..probably I should use dpontīs color + layer, anyway...I skipped that in nodes and entered the color and luminosity channel envelopes in standard layers, and added the suncolor modifier from there, so that worked.

I also can control the cloudīs diffuse values in standard layers ...to boost light diffusion so to speak, but here I canīt use the suncolor modifier, since it isnīt built to be used with that, otherwise I think that could be nice to have, right now I get it quite nice overall when changin sun pitch, except the diffuse channel donīt follow with that, so it might be best to have it off, though I need to jump in to nodes and see if I can add a node to boost the luminosity instead.

prometheus
05-26-2015, 01:47 PM
I have some issues with using the sunsky suncolor modifier in the surface standard layer color channel envelope, it works fine when working on the scene, but if I reload the scene, it isnīt recognized in vpr, the suncolor modifier is still there though, but the function of it seems gone, and no matter if I deactivate and activate the modifier, it will still not recognize the sunsky suncolor properly, so my cloud layer remains just white....however, I can remove the envelope and setup a new one, then it will work again, but I think something needs to be fixed here perhaps.

I will post samples or images to showcase, or put a vid up on the tube tomorrow.
using windows 7 lightwave 64 bit 11.6.3

Chrusion
05-26-2015, 02:38 PM
Thanks for the HV cloud emitter description, Prom. I was wondering if an emitter texture was used or not. LOL... yeah... your scene scale kinda got out of hand. hehe. Those be some mighty BIG clouds!

prometheus
05-26-2015, 04:16 PM
Thanks for the HV cloud emitter description, Prom. I was wondering if an emitter texture was used or not. LOL... yeah... your scene scale kinda got out of hand. hehe. Those be some mighty BIG clouds!


Check my atmospherics thread, I just posted a new session clip without voice, just checking hv clouds again and a cloud plane with transparency and sunsky suncolor, this one is actually more realistic in scale.

http://forums.newtek.com/showthread.php?146615-Atmospherics-with-dpont-sunsky-sprites-soft-cloud-whisps-fog-and-related&p=1432593#post1432593

Chrusion
06-16-2015, 01:16 PM
Denis,

I need to wake this thread up again... A ground mesh with bump maps becomes illuminated from underneath when Turbidity in SK_Sky light (and/or SunSky proc. texture) is less than 4 and SK Sun light Time places the light below the horizon (but before it fades to zero intensity) using the Preetham model. The H&W model does the same (slightly less intense), but with turbidity values less than 8 - 10.

If you set Bump intensity in surface editor to 0%, the surface ceases to be illuminated from underneath. The intensity of illumination is proportional to bump value (200% is almost twice as "bright" as 100%). I even tried placing a large poly under my ground mesh, normal facing down, thinking it would "intercept" the light rays coming from below and cast a shadow on the ground mesh. It was totally ignored, even when both surfaces were set to double sided.

Please fix, cuz I need to animate a time lapse sunrise with turbidity less than 2.0 (less reddness surrounding sun disc), but can't because the ground renders like angry lava in the pitch black of night and right on up through dawn. The shading becomes normal as soon as the pitch of the SK Sun crosses from negative to positive.

Thanks.

dpont
06-16-2015, 03:12 PM
...Please fix, cuz I need to animate a time lapse sunrise with turbidity less than 2.0 (less reddness surrounding sun disc), but can't because the ground renders like angry lava in the pitch black of night and right on up through dawn. The shading becomes normal as soon as the pitch of the SK Sun crosses from negative to positive...

Not a bug, just a collateral effect of this new feature,
was requested for softening sunrise or sunset animation,
don't know your scene,
but you may fade the Sun Light yourself with the Light Intensity envelope.

Denis.

spherical
06-16-2015, 03:12 PM
Placing a poly below may not work, because the light is coming from the side. Try extruding the ground, so that it is a closed mesh on all sides.

spherical
06-16-2015, 03:17 PM
So, it's effectively turning on Translucency.. or an equivalent of that?

dpont
06-17-2015, 12:06 AM
I get sometimes this issue, not especially with Sunsky
with not closed geometry, normal map and back light,
so a shading/occlusion issue, needing some compromise,
but not easy to say without knowing the object and the scene,
this is not predictable from the lighting system itself,
and again it is more practical to fade
an exceeding effect, which is revealed by shading
than having a brutal fall down of the sun light
(like in the original sky model),
or adding something for occluding the light
before the shaded object (a tedious task, I must admit).

Denis.

prometheus
06-17-2015, 03:35 AM
Havenīt experienced the issue and havenīt checked similar setup, a scenefile provided showcasing it would be easy to track.
Just a thought, wonīt an extremly large groundplane solve it? maybe making a skydome with a closed geometry and capped ground so the skydome is both sky and ground in one mesh? and just make different surface for the ground cap and sky dome.
and the actual terrain mesh? can you zero out the edges on it, so it is smoothly blended at the ground level.

Michael

Chrusion
06-17-2015, 09:33 AM
Here's the scene I'm working on... (Forum is not letting me upload this zip, even if the two large images are removed)... thus it's on my Dropbox: SunSky_BelowHorizonShading.zip (https://dl.dropboxusercontent.com/u/30741269/Bugs/SunSky_BelowHorizonShading.zip)

Enable VPR. Note that the ground renders normally from frames 0 - 49 and 250 - 300. Change Turbidity from 2.5 to 1.5 (Preetham) and note the ground illuminates when Sun pitch goes negative degrees. 2.5 was as low as I could go before the "inverse shading" of bump normals occurs. 3 and 4 pretty much prevents it. Again H&W model needs higher Turbidity to prevent "inverse bump" shading. Note that the ground geometry is an enclosed object. A weight map prevents the bottom extrusion from being displaced by the procedural texture. So, despite the presence of this shading geometry, and it having full RT shadow casting/recving enabled, the procedural/image mapped bumps are still being illuminated. Bumps from displaced polys shade just fine (ie, mountain geometry IS being correctly shaded and NOT being lit from underneath)... it's the perturbed normals that are receiving light from SK Sun, not the actual poly normals. If you're wondering why the Sun light Preview is 10km, this distance matches the size of my HV cloud emitter and results in much better HV bottom illumination than when set at 6,370 Km.

Not sure what happened, but illumination on the HV clouds was decreasing to zero (frame 0 and 300) prior to running LW's Package Scene. Now they remain under lit in red light, even though the color of the Sun light = 0,0,0 and the Sun Time is enveloped so it's a good hour before/after sun rise/set and thus have zero intensity. The secondary clouds and visible SK sky are mapped on the sky dome with Luminosity driven by a node tree based on pitch angle of SK Sun. This fades the secondary clouds to black when the sun goes below the horizon.

ANOTHER artifact to note: The brightness of the sky (backdrop plugin for fog only, and procedural texture for visible sky on sky dome) increases by about one stop going from frame 48 to 49 and 249 to 248, exactly when the Sun light crosses from negative to positive pitch (also the same time the light color changes from orange to black). IOW, there's something going on when the light's pitch crosses zero degrees that's affecting shading across the board. And question of the day: Why does the Sun light continue to render as red on HVs, even though its color immediately changes to black when pitch goes negative?

Also, the fading of the sun light's intensity below 0 degrees is too abrupt at its "end points," fading out in 2 - 3 frames. I can mitigate this by easing in/out the Time envelope with tension 1 (or exaggerate the outgoing/incoming curve more by switching to splines and pulling the handles out), but time is linear, not "curvy", thus not the best way to fix it in order to get a smooth transition from pitch black!

prometheus
06-17-2015, 02:06 PM
To much info to melt tonight, just opened your scene to check it, will have to take a look at bump & issues tomorrow, got to go to sleep now.

I would give these advices on the hvīs though, you have a local density gradient on the thickness channel, that has never worked in that channel, besides..it is inactive too, but it wonīt help even if it was active, so you can remove that.
you got it right with distance to camera gradient in the dissolve channel, but here you should also have the local density gradient..I usually start with local density gradient in the dissolve channel and then add the distance to camera gradient set to additive mode, it will dissolve a lot maybe, but compensate the overall density by raising the density value in the density channel.

you also have textured shadows on the the shading tab..that will raise your rendertimes extremly to the roof, sure ..at some stages it can give that extra realism ..but you can get it close with just setting the right shadow strength..in yours you got 90 strength, I would suggest turning it down to very very low shadow strengt instead, maybe 0,5-2.
If you do want that extra realism and donīt care that much about render hit, by all means..use textured shadows.

you also have constant illumination, I would suggest change it to rayleigh or beer illumination.

you also got a local density gradient in the luminosity channel, I think you could survive without that, it will give your clouds illumination even when the sun pitch is almost at the horizon, and that wonīt be realistic.

You have a texture speed of 0,05 but you have no texture effect, so if you tried to follow my settings, it wonīt work, you need the displace effect, though I would be careful to use it if you animate a timelapse with clouds moving.


otherwise I think you have set it up pretty nicely, terrain, fog and distance looks right, same with the use of sunsky as fog layer only on textured environment and sunsky applied on the skydome.. clouds overall is quite nice, both in hypertexture, particle size, variation and stretching, though I see you have turned of the particles to not be affected by fog, that is something I donīt do, clouds should be affected by fog, itīs a bit hard maybe to tweak right, but at least some amount of fog, you can set fog level from 0-100% for the particles.


I would perhaps raise the cloud size of the textured layer you have on the skydome and the weather procedural, generally I set it to 1-2 in size, but it is of course dependent on other scale values.

prometheus
06-17-2015, 03:18 PM
I think the red hvī artifact is due to the local density luminosity..but you say, that is no color information, true..but this is a computer simulation not real world, in fact..since you have local density in the luminosity channel, the hv clouds are still lit up by some light information even though the light pitch is so low, and it retains the red color since there isnīt any coding there to cope with such circumstances I would guess, it should behave correctly if you make sure the clouds are not illuminated by anything when the sun is so low down way beyond horizon, so turning off the local density gradient in luminosity as well as making sure it has no ambient intensity, that would make the clouds emitt no light and thus no even the appearance from being red..the clouds will simply be black..at night time you would also have to deal with if there is a moon in itīs right phase to light up the clouds in a completly different way than the sun, for that we would need to add additional moonlight...but sunsky isnīt that advance so it can create a moon light setup in combination with the sun and also balance it correctly, not even vue has such option.

Though vue is designed to work and take care of the full atmospheric and light spectrum together with cloud layers, But the dp sunsky isnīt developed in conjunction with hypervoxels to work flawlessly in the same way, so in most cases vue provides a more realistic balance from scratch when doing sunsets etc and cloud color and light balance, hvīs does it pretty realistic most of the times..but you have to balance it more manually than in vue.

Note..I also changed sun to manual control, it seem to look better, it may be that the sunspot modifier from where you set location etc may not be ideal for this...not sure though.

Michael

Chrusion
06-18-2015, 12:44 PM
you have a local density gradient on the thickness channel, that has never worked in that channel,....Yep, just experimenting. Deactiving confirms it doesn't work, but it does work with Distance to Camera... thins out and helps removes detail at horizon. Removed it anyway.


you should also have the local density gradient... in the dissolve channel and then add the distance to camera gradient set to additive mode,...Again, just experimenting with and without.


you also have textured shadows on... that will raise your render times extremly Didn't seem to make a big difference in VPR render times and visual result, nor did changing intensity. [edit: Never mind... I turned up thickness, which made dark, angry bottoms, then turned down shadow strength to 0.2 - 0.5 and BAM! MUCH lighter, fluffier clouds!]


you also have constant illumination, I would suggest change it to rayleigh or beer illumination. I changed to constant because the other two made the cloud interiors much darker. I'm trying to get those evenly and brightly lit, puffy cumulus clouds. Their edges/rims get way overexposed, while the bottoms and central areas remain stormy gray. I'm looking outside now at a bright, hazy, hot, cumulus-filled sky and just cannot replicate the "white inside and out" look. I took Thickness down to 10 and it helped a great deal, but mainly because the density (not the parameter) became more transparent, thus lightening the interior stormy darkness.


you also got a local density gradient in the luminosity channel, In an attempt to brighten the inside and bottom of the cloud... to not much avail. Edges bloom out before interior gets to where it sort of brightened up a smidge.


You have a texture speed of 0,05 but you have no texture effect... Didn't help in adding detail in my experiements, so I changed hypertexture from Turbulence to Windy Wave, which has MUCH finer detail in the wispy filaments.


I see you have turned off the particles to not be affected by fog... Tried it both ways. Fog ended up darkening and subduing the clouds too much, even after dialing up Luminosity. Thus, resorted to camera distance dissolve to get them to blend with the sky, independent of Fog min. dist. param.


I think the red hvī artifact is due to the local density luminosity... It would help if I made the bottom half of the terrain mesh (below Y=0) to be as large as my HV cloud object! Now that it is, it shades the HVs as desired with a progressive advancement of the under-lighting moving towards the camera as the sun moves up from below Y=0.


but you say, that [there] is no [light] color information, true..but this is a computer simulation not real world... Obviously! I just found it curious why the red-orange of the SK Sun exists when the auto-generated color of the light changes to black one frame to the next, but NOT affect the scene... OH FREAKIN' FUDGE! Now the light isn't changing to black at negative ptich! It's staying deep red hours before/after sun rise/set. That would explain why the HVs remain under lit with red. Honestly! The light DID change instantly to black at one time. Don't know why it isn't now. Weird.

Thanks for all the tips. I still want to discover the secret to "white inside and out" cumulus clouds... not white, over blown edges/fringes and stormy "black" interiors/bottoms. (see above edit - only "problem" now is how to get white clouds as they picking up the milky orange color of the sun).

Chrusion
06-18-2015, 02:07 PM
Not understanding this... Distance to Camera HV Volume Dissolve gradient is making my clouds SMALLER the farther away they are! It's NOT fading them out at the size they are, but making them smaller until there's nothing left. That's not the way it's supposed to be. Dissolve is supposed to make something more and more transparent, not change the size until there's nothing left.

prometheus
06-18-2015, 02:49 PM
Yep, just experimenting. Deactiving confirms it doesn't work, but it does work with Distance to Camera... thins out and helps removes detail at horizon. Removed it anyway.

Again, just experimenting with and without.

Didn't seem to make a big difference in VPR render times and visual result, nor did changing intensity. [edit: Never mind... I turned up thickness, which made dark, angry bottoms, then turned down shadow strength to 0.2 - 0.5 and BAM! MUCH lighter, fluffier clouds!]




I changed to constant because the other two made the cloud interiors much darker. I'm trying to get those evenly and brightly lit, puffy cumulus clouds. Their edges/rims get way overexposed, while the bottoms and central areas remain stormy gray. I'm looking outside now at a bright, hazy, hot, cumulus-filled sky and just cannot replicate the "white inside and out" look. I took Thickness down to 10 and it helped a great deal, but mainly because the density (not the parameter) became more transparent, thus lightening the interior stormy darkness.

In an attempt to brighten the inside and bottom of the cloud... to not much avail. Edges bloom out before interior gets to where it sort of brightened up a smidge.


Didn't help in adding detail in my experiements, so I changed hypertexture from Turbulence to Windy Wave, which has MUCH finer detail in the wispy filaments.

Tried it both ways. Fog ended up darkening and subduing the clouds too much, even after dialing up Luminosity. Thus, resorted to camera distance dissolve to get them to blend with the sky, independent of Fog min. dist. param.

It would help if I made the bottom half of the terrain mesh (below Y=0) to be as large as my HV cloud object! Now that it is, it shades the HVs as desired with a progressive advancement of the under-lighting moving towards the camera as the sun moves up from below Y=0.

Obviously! I just found it curious why the red-orange of the SK Sun exists when the auto-generated color of the light changes to black one frame to the next, but NOT affect the scene... OH FREAKIN' FUDGE! Now the light isn't changing to black at negative ptich! It's staying deep red hours before/after sun rise/set. That would explain why the HVs remain under lit with red. Honestly! The light DID change instantly to black at one time. Don't know why it isn't now. Weird.

Thanks for all the tips. I still want to discover the secret to "white inside and out" cumulus clouds... not white, over blown edges/fringes and stormy "black" interiors/bottoms. (see above edit - only "problem" now is how to get white clouds as they picking up the milky orange color of the sun).

puffy cumululs clouds on particle field like this is almost impossible, unless you use the gardner clouds or turbulent noise to acheive they hypertexture effect with only a few particles or points, not on large cloud cover, then itīs a matter of setting the shading right of course, not sure exactly what special look you are after so hard to say.


Not understanding this... Distance to Camera HV Volume Dissolve gradient is making my clouds SMALLER the farther away they are! It's NOT fading them out at the size they are, but making them smaller until there's nothing left. That's not the way it's supposed to be. Dissolve is supposed to make something more and more transparent, not change the size until there's nothing left.

That is strange, I donīt perceive it like that....

Regarding textured shadows...

Believe me... textured shadows are much slower both in VPR and without, I donīt understand how you can fail to see the difference in vpr update with and without textured shadows on, and by the way...always do a final render and you will find out the difference in render time with textured shadows on or off.

Regarding constant illumination...

real clouds are reacting to the sunlight, what you are doing is overcompensating it to look how you want the clouds to be looking without relation to how the sun is affecting it in real life, that would be wrong...by all means, sometimes you may want to artisticly change it as you want, but you could also go for the ..how does it behave in real life, if you should follow the lighting rules to get whiter fluffy clouds overall..you would probably need to change sun angle and let the sun light affect it head on as it does in real life.

regarding finer detail in hypertextures with displace effect, you are wrong...
you sent a file with hypertexture turbulence and a 0,05 speed effect without any speed effect choosen..so it wonīt work, you said you changed hypertexture..well that is a different thing and of course it may help giving other type of finer detail, but the point is ..Stilll...if you had used a working speed effect (displace) at 0,05 it wouldnīt work...since your overall scale was larger than in my scenes I think, at larger scales you need higher values, so if you were to select displace effect and change effect speed to 1 or 2, then you would see the obvious change, I would recommend not using jitter samples while doing it since that interferes with the look.
And...I think you had to low hypertexture amplitude for that effect to work properly, probably should raise it to 150-200

the fog..
well you can control fog level, just a slight bit of fog helps making them blend in better with the environment in most cases, it may be a case by case thing though depending on what you want.

About fluffy clouds and shadows..
, textured shadows(depending on light angle) will of course cast internal cloud shadows on itself, so at some times that could of course enhance realism...but at costly rendertimes.

prometheus
06-18-2015, 03:20 PM
About fog by the way, I said in many cases fog is helping blending the clouds with the rest of the sky environment, of course..in some situations fog might not reach that level of height as the clouds are, so ..sure it can work nicely without fog, there is however the haze factor ..which often reaches higher altitudes I think, that is harder to simulate with just sunsky/sunsky atmosphere and get a realistic behaviour with clouds as we can do with vue.

Chrusion
06-19-2015, 07:08 AM
Re. Distance Dissolve... HVs geometric size isn't getting smaller, its actually dissolving out according to local density, ie. dissolving from the outer edges (less density) inward (more density), making it appear that the geometric size is getting smaller.

What works for me is a distance gradient on Thickness. Farthest key away from camera = 0%, then a 10% key about midway between farthest and closest, then a key at desired base density at desired minimum distance.

Your other points are correct. Displacement does work when properly adjusted. Rayleigh and Beer models react to light position, etc. (Beer giving a more constant illumination vs. light incident angle). Texture shadows is much slower, etc. etc.

prometheus
06-19-2015, 08:51 AM
Re. Distance Dissolve... HVs geometric size isn't getting smaller, its actually dissolving out according to local density, ie. dissolving from the outer edges (less density) inward (more density), making it appear that the geometric size is getting smaller.

What works for me is a distance gradient on Thickness. Farthest key away from camera = 0%, then a 10% key about midway between farthest and closest, then a key at desired base density at desired minimum distance.

Your other points are correct. Displacement does work when properly adjusted. Rayleigh and Beer models react to light position, etc. (Beer giving a more constant illumination vs. light incident angle). Texture shadows is much slower, etc. etc.

Thatīs what I was about to warn you about, but you only mentioned distance to camera so I didnīt bother, but yes, local density is dissolving out the whole volume...thus it can look smaller, you know you can compensate by increasing the actual density value in the density channel, or change hypertexture contras(if you use turbulence) other hypertextures have other settings to adjust things like that.

I got a very nice fluffy cloud with your scenefile, by keeping local density gradient in the luminosity channel, together with rayleigh illumination if you adjust shadow strenght and opacity in the right balance, and using texture shadows...but it isnīt ideal to make sun timelapse on that since the local density illumination would look all wrong on other angles.

Draft vpr renders...

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