PDA

View Full Version : Best method for sky and clouds without commercial plugins?



Sebasvideo
03-18-2014, 03:40 PM
What would be the best way to create a realistic sky with LW 11.6.2? Skytracer to me is out of the question because the clouds it produces look nothing like any clouds I've ever seen in real life, not to mention that it makes the rendering times impossible. Do you just do some clouds with hypervoxels in the background? If so, what settings do you use? I've been playing around with them a while ago, but I never got to a perfect result. It sucks that the cloud presets in HV don't look anything like real clouds either, they're just a starting point.

prometheus
03-18-2014, 04:07 PM
What would be the best way to create a realistic sky with LW 11.6.2? Skytracer to me is out of the question because the clouds it produces look nothing like any clouds I've ever seen in real life, not to mention that it makes the rendering times impossible. Do you just do some clouds with hypervoxels in the background? If so, what settings do you use? I've been playing around with them a while ago, but I never got to a perfect result. It sucks that the cloud presets in HV don't look anything like real clouds either, they're just a starting point.

yeah, think we have had that discussion before?
The HV presets are mainly to use on single null objects, and they arenīt set up to work from scratch to look like they actually do in the preset thumbs, you have to set light sources correctly and some other stuff.

But basicly I think you are best of to use particles or create point clusters in modeler.

The best is to simply use real photos for still, and animated photage if that is needed, limitations are that they are non interactive to adjust lighting and sun sources of course, and not volumetric so fly throughs are a no no.
hypervoxels are your only option otherwise to get semi decent realism, some have done some tricky procedural approaches on polyplanes in different layers...but it takes to much time to set up in my opinion.

Ivé been experimenting with using cloud still and animated photage on to polyplanes too, to make sure they cast shadows on the ground to simulate more realism in overall shadow density covering all objects...but I have to revisit that.

And you have seen my samples on vimeo, Im not 100% percent pleased with what you can do with hypervoxels...if we do get the same geometric appliance as now modo implemented it, it will become much better I think.
but you will always face huge rendertimes regardless of using hypervoxels, or ozone, ogo taiki, or turbulenceFD..turbulenceFD might be faster in some cases..but it will be troublesome with huge clouds, and with subgrid detail increasing rendertimes.

I donīt think there is any other options really than those
http://s3.amazonaws.com/forums.content.luxology.com/images/full/9aa7058776411ca99dd9b227b95f341c.jpg
http://s3.amazonaws.com/forums.content.luxology.com/images/full/9aa7058776411ca99dd9b227b95f341c.jpg

Thereīs really no magic button for modo,houdini or vue either, though vueīs volumetric lighting and shading for clouds are more realistic, including a true spectral atmosphere...which we donīt have in lightwave, thou sunsky sort of is that, but not fully volumetric in terms of fog and haze.
And modo has sort of better voxel engine now than hypervoxels, houdini is amazing too...but takes time to render as well.
All volumetric stuff takes time..and hypervoxels isnīt that bad in speed, even though it lacks the faster shadow mapping which is available in modo.

Sebasvideo
03-18-2014, 04:12 PM
Yes, I remember we had talked about that and you had some great samples, but what I was able to do wasn't too promising. But mostly I was wondering if most people are just using HVs or if there's something better out there, kind of like Skytracer but that is realistic and doesn't take ages to render. Obviously it's going to take longer to render clouds, but a frame that renders in 10 minutes without HVs, when add Skytrace 2 it tells me it's going to take 90 minutes or more, so no, thanks.

Thanks Michael for reminding me about the point clusters, I'm trying to learn so much stuff at the same time that I forget some of it.

prometheus
03-18-2014, 04:21 PM
Yes, I remember we had talked about that and you had some great samples, but what I was able to do wasn't too promising. But mostly I was wondering if most people are just using HVs or if there's something better out there, kind of like Skytracer but that is realistic and doesn't take ages to render. Obviously it's going to take longer to render clouds, but a frame that renders in 10 minutes without HVs, when add Skytrace 2 it tells me it's going to take 90 minutes or more, so no, thanks.

Thanks Michael for reminding me about the point clusters, I'm trying to learn so much stuff at the same time that I forget some of it.


I donīt like skytracer and hope they drop it or create something new, Ivé told you some of the stuff you need to be aware of to make hypervoxels render faster, and why they render slowly in some cases.
skytracer often needs textured shadows for good cloud looks, if we talk about fuller volumetric look, and that is even slower than hypervoxels, skytracer canīt cast any shadow rays on the ground either, and you canīt fly over them either.

I generally just add sunsky to the scene, add a particle emitter that is huge in size, and use a lot of particles sometimes, using birth rate to add variations in the particle volume for the global cloud density look.
sunsky needs to be set to use the sk sun, and I use the manual mode so I can rotate the sun manually exactly where I want.

I sometimes use volumetric fog with the use of "use background color" that takes on the sunsky environment as the fog, and you get the hv clouds to fade in the fog nicely, but you have to be careful and set proper fog distance and
also sometimes correct the fog level in the particle emitters object properties render panel.
using background color isnīt perfect, it sometimes gives some render artifacts depending on object in front.

Michael

Sebasvideo
03-18-2014, 04:22 PM
Great, I'm going to try all that :)

prometheus
03-18-2014, 04:26 PM
you can simple draw polygon shapes in modeler, and use the fill solid tool, the fill solid tool is hidden and you have to search in your menus for it, it will fill any object with particles.

You can also use a partigon emitter, use birtrate with procedural textures to shape the cloud density, then save out transformed, and load to modeler for further tweak, though such cloud clusters are static...until you morph them or deform somehow.


hereīs is a particle emitter with its particle motion using velocity motion ..that is set in the particle tab.
http://vimeo.com/67990100
This one is also using a particle emitter ...
http://vimeo.com/86189990


Fractals one a poly plane, some volumetric lights.
http://vimeo.com/57671552

Some old ozone demo stuff
http://vimeo.com/39122792

http://vimeo.com/39072395
Michael

Sebasvideo
03-18-2014, 04:28 PM
Excellent stuff, thanks again for all your help!

prometheus
03-18-2014, 05:30 PM
sprites might be a fast alternative in some cases, not fully realistic due to light and shadow options missing and not truly volumetric, takes some texture gradients or prodedurals additionally in lum and color channel to get something decent, also might be worth changing volume slices to 3 or 5 ..depending on how it looks.

here it is on some point clusters ..I used the pen tool to draw simple flat cloud shapes in top view, and filled it with points with the fill solid tool, then I copied those to another layer, moved them up to another cloud height and pasted back to the first layer again, so I had two heigh levels of point clusters, you could also just clone it in layout, but then you will run in to render sluggish behavior, since hypervoxel need to treat them as seperate voxel groups adding much more calculation time for it all, here lies also a workflow issue with lightwave as a split app, you canīt just move the two segments directly in layout.

Same goes for using very large single null clouds, they will halt in render if they overlap with two big voxels, if we could manipulate points directly in layout, we could simply use two or three points and move, and since they belong to the same point cluster, it only takes one hypervoxel instance and they will render faster.

The sprite clouds fade away at the horizon, since I use realistic volumetric fog, and background color takes on the sunsky environment, max distance is controlling how much/far away it will take for the fog to
affect the clouds.
Render time in VPR -1.6 seconds, final render at hd resolution took 14.6 seconds, rendertimes were without any antialiasing in the image.

http://forums.newtek.com/attachment.php?attachmentid=120879&d=1395185127

120879


Michael

prometheus
03-18-2014, 05:52 PM
I would like to get my hands on a demo of helios or something, Helios was released not long ago, and works as a module plugin for vue xstream and should be working with lightwave(with xstream) and the other xstream platforms.
It will cost though:)

http://www.quadspinner.com/Helios/Index
http://www.daxpandhi.com/?tag=/helios
http://www.quadspinner.com/Helios/Features

gjjackson
03-18-2014, 07:10 PM
Doesn't DPont have something for this. Haven't used it but I thought there was something.

prometheus
03-18-2014, 07:39 PM
Doesn't DPont have something for this. Haven't used it but I thought there was something.

Yes..but that is mentioned above, itīs sunsky ..which is a realistic skymodel, but it donīt have any clouds in volumetric form or in textured layers, but can be used with hypervoxels and textured environment.

Michael

vector
03-19-2014, 03:18 AM
I must say I never tried, but it's something I would like to do: Clouds in Blender

Although solve it in LW directly is more confortable :)


https://www.youtube.com/watch?v=uK2l6Yrtqhg

prometheus
03-19-2014, 06:25 AM
I must say I never tried, but it's something I would like to do: Clouds in Blender

Although solve it in LW directly is more confortable :)


https://www.youtube.com/watch?v=uK2l6Yrtqhg

Huh...some of these days I will have to face that blender demon with a sword of patience, tried it before but couldnīt stand the UI, and general workflow..even though it looks better.
Itīs still tedious it seems to set things up like this, In fact Lightwave hypervoxels is one of the faster/easiest voxel module to get up and running..the issue is the neglectance of it all for years, and the quality of
the voxels shader, but setting up particles like this and add voxels is way more easier in Lightwave.

Yes, it looks good though, not entirely sure if the volume shader is applied on the particles, or if the particles only serves as a density controller for the volume container to follow?
Render speed seems quite fast too, you do not have any VPR in blender..so tweaking is a bit cumbersome.

He used a lot of particles here, over 80 000, I also use a lot of them sometimes in lightwave for particle cloud container, maybe not 80 000, it depends on.
What we can see here is Way much better smoothing between voxels, but I am as I said not sure if that is due to the voxel type per particle, and blending between them, or... if it is applied on a full volume container?

I also see that blender has falloff curves, and that is exactly what I wanīt in lightwave for controlling thickness, and offset of the hypertexture.
I also can see that clouds is only one part of it, it generally donīt look real because he is just adding some gradients for the sky, if he were to have a spectral sky model, like sunsky for lightwave..It would have looked better.

CloudfX for houdini is really cool, you can simply drag the cloudfx tool icon upon any point cluster/particles or on to any sculpted geometry, and it will take itīs form..with a full cloudRig with lighting controllers set up for you.
several different ways off adding multi noise functions for different scaling, a density curve for soft cloud edges but retaining thicker volume on the inside...the best part is too tweak it all in almost realtime openGL.
What I donīt like about it in houdini..houdini takes a long time to start iīts renderer, and to get noise free clouds..you have to raise quality that much so it will render slow anyway, I also do not get the same feedback
for controling the overall sky, as I do with sunsky in Lightwave..sunsky in lightwave can be seen directly in openGL, and of course while using VPR for much faster feedback than what you can see in houdini.


Michael

prometheus
03-19-2014, 06:30 AM
hereīs is some of the issues ...if solved we could have much better looking hv clouds.

1. particle blending isnīt good enough...check modo,houdini, and the old dynamite plugin blending for
lightwave.

2. Geometry volumetric isnīt possible.

3. texture falloff isnīt working.

4. thickness lacks a proper gradient or density curve.

5. Distance between particle gradient is missing in channels.

6. Faster shadow mapping would be nice.

7. better And controllable scattering control for the illumination of both mie/rayleigh methods. (in modo forward scattering control) (houdini light propagation controls) (helios-subvaper control)