PDA

View Full Version : Daytime moon



Ma3rk
10-30-2018, 11:23 PM
I'm looking for some pointers on how to set up a node surface for a billboard of a 3/4 waining full moon in daytime. If you're where it's clear & noticed (been happening the past few days), the shadow portion just blends into the blue sky.

In After Effects, I'd do something with a luma & alpha mattes, but not sure quite how to go about that in LW. I kinda sorta have it working but not with the contorl I'd like.

TNX

prometheus
10-31-2018, 06:17 AM
I'm looking for some pointers on how to set up a node surface for a billboard of a 3/4 waining full moon in daytime. If you're where it's clear & noticed (been happening the past few days), the shadow portion just blends into the blue sky.

In After Effects, I'd do something with a luma & alpha mattes, but not sure quite how to go about that in LW. I kinda sorta have it working but not with the contorl I'd like.

TNX

Fake it with transparency..if nothing is
Behind the moon.
Or if using hv sprite clip..try dissolve.

Ive done this ages ago.
At work having lunch..so I can't give
A Proper showcase right now.

prometheus
10-31-2018, 06:19 AM
You should also use light incidence angle for any such gradient in dissolve or trasnsparency channel.

SBowie
10-31-2018, 07:33 AM
If you're where it's clear & noticed (been happening the past few days), the shadow portion just blends into the blue sky.You know I'd never thought about this, yet it sounds right - which (at risk of a tangent) makes me wonder why this is so ... I could guess, but does anyone know the physics (or optics) involved?

art
10-31-2018, 07:48 AM
I don't know exactly why but if the shadow portion of the moon is as black as the rest of the sky around it then atmosphere "filter" is applied equally to both the black sky and black part of the moon making them both the same. I think?
On some days when the shaded part of the moon is not as black and you can actually see it, also colored blue.
Wasn't there a tutorial on exactly this in an very very old LW book (no nodes, though)?

prometheus
10-31-2018, 07:54 AM
You know I'd never thought about this, yet it sounds right - which (at risk of a tangent) makes me wonder why this is so ... I could guess, but does anyone know the physics (or optics) involved?
Probably the same reason we do not see the dark space...atmospherics.
And it will tint cover anything thst doesnt emitt light strongly enough.

In the 3d world...a sk.sunsky is purely a backdrop
..we would need volumetrics to make the moon fade away where it is in a veil of shadows...and actually a strong light or volumetric light to simulate rays from the moon...and in such case it wouldnt work with a luminous surface on a sphere.

prometheus
10-31-2018, 01:42 PM
The basic stuff....though if you want something advanced such as a two moon or more moons hanging in a scifi-scene, and one moon obscuring the other, this wonīt be working so good with transparency.

https://forums.newtek.com/attachment.php?attachmentid=143255&d=1541014885

Ma3rk
10-31-2018, 08:00 PM
You know I'd never thought about this, yet it sounds right - which (at risk of a tangent) makes me wonder why this is so ... I could guess, but does anyone know the physics (or optics) involved?

I'm pretty sure it's just the refraction & skattering of the sky color; similar to why when looking into a hole poked in snow on a clear day looks blue too. I know we covered this in my college physics, but that was way too many decades ago.

jeric_synergy
10-31-2018, 08:39 PM
When the Moon is visible during (Earth) day, there's probably a fair amount of "Earthshine" hitting the moon, because obviously the Earth is quite bright at such times.

TO THE INTERNET!!!


"The Earth is much brighter in the Moon's sky than the Moon in Earth's sky. Not only is Earth 3.6 times 13 times larger by angular area, but its average albedo of 0.37 (meaning Earth reflects 37% of the Sun's light on average) is more than three times higher than the Moon's (0.11)."

Ma3rk
10-31-2018, 08:44 PM
You should also use light incidence angle for any such gradient in dissolve or trasnsparency channel.

I'll look into that. At the moment I've been just using a gradient.

The scene is using an HDR enviro light & a Texture Environment for the bg and just using GI so not sure how you'd set incident angle for that.

The billboard of the moon is a pretty high rez HDR as well an at present just using a Standard material. I am using some object dissolve (~38%) for transparency to blend but running into the issue of if I get the dark side to look correct, it's not bright enough for the lit side. I can kick that up some on the image map but it still wasn't right.

I've a very subtle volumetric fog for atmospheric and letting that affect the moon object, so distance from camera becomes a factor.

Ignore ground at present. That's a WIP. Still discovering some UV & texturing issues too.

143258

prometheus
11-01-2018, 04:46 AM
When the Moon is visible during (Earth) day, there's probably a fair amount of "Earthshine" hitting the moon, because obviously the Earth is quite bright at such times.

TO THE INTERNET!!!


"The Earth is much brighter in the Moon's sky than the Moon in Earth's sky. Not only is Earth 3.6 times 13 times larger by angular area, but its average albedo of 0.37 (meaning Earth reflects 37% of the Sun's light on average) is more than three times higher than the Moon's (0.11)."

To me it doesnīt sound reasonable that such earth shine would yield any significant energy for the moon to emitt that earth shine light back strongly enough to be visible in earth atmosphere.
It would be secondary reflected light, sunlight first hits the earth and then need to travel to the moon, then reflect that "earth shine"light again back through earth atmosphere, and for the earth to have a full cycle of the whole earth shine, I suspecty the sun would need to be behind the moon in a straight line I guess, and thus it will loose any direct sunlight, leaving it with only the earth shine light to illuminate the moon, and maybe a slight rim light on the side of the moon.

So I just donīt think that earth shine is contributing in a significant way to the appearance of the moon blending in to the earth atmosphere, picking up the same color which sort of gives the illusion of fading away.

I am guessing itīs just air refraction together with atmosphere thickness that determines which light and how much is penetrating enough to be visible.

I am no expert in physics though, so from me it is foremost guessing.

jwiede
11-01-2018, 12:53 PM
Probably the same reason we do not see the dark space...atmospherics.
And it will tint cover anything thst doesnt emitt light strongly enough.

Exactly. The scattered sunlight in the atmosphere effectively "drowns out" both the darkness of space, and the darkness of the moon's shadow in the same manner. The only way things show through the atmosphere is if they're adequately brighter than the atmosphere's brightness level (also why celestial objects aren't typically visible during daytime).

Darkness is the absence of light.

prometheus
11-01-2018, 01:29 PM
Exactly. The scattered sunlight in the atmosphere effectively "drowns out" both the darkness of space, and the darkness of the moon's shadow in the same manner. The only way things show through the atmosphere is if they're adequately brighter than the atmosphere's brightness level (also why celestial objects aren't typically visible during daytime).

Darkness is the absence of light.


Yup...

Maybe this may be helpful..though the question "Why transparent" actually is a false conclusion, and for the false world, transparent is exactly what the moon object is in my sample here, as a fake for the lack of atmospherics.
https://www.quora.com/Why-can-you-see-the-blue-sky-through-the-moon-when-its-visible-in-the-daytime-Why-is-it-transparent

Shawn Farrell
11-01-2018, 04:41 PM
Who can forget the daytime blood red moon over the pyramids quite the blend-in also...:

http://www.soundtraxxmusic.com/LightWaveSpeedEDITORB.jpg



https://www.youtube.com/watch?v=t89BbuArwxU&t=4s?autoplay=1

:vticon::vticon::vticon:
:newtek:

Ma3rk
11-02-2018, 12:36 AM
I switched to a Delta material for the moon object, and that with some matte & luma manipulation into a gradient for surface transparency is getting there. Think I need to kick the volu fog up just a bit or tweek distance settings. In any case, I'm just bummbling along with this so open to better techiques.

Knocked the main enviro light down some as well.

143265

prometheus
11-02-2018, 06:38 AM
Who can forget the daytime blood red moon over the pyramids quite the blend-in also...:

http://www.soundtraxxmusic.com/LightWaveSpeedEDITORB.jpg



https://www.youtube.com/watch?v=t89BbuArwxU&t=4s?autoplay=1

:vticon::vticon::vticon:
:newtek:


A bit odd with that much specularity, but for weird artistic freedom, guess thatīs ok:)

Shawn Farrell
11-02-2018, 09:05 AM
A bit odd with that much specularity, but for weird artistic freedom, guess thatīs ok:)

It's from another time...ancient yet future also...specularity shifts over large amounts of moon time especially when father SUN comes to visit it's like he is emotional...
http://www.soundtraxxmusic.com/1000yearsyoutube.png

:vticon::vticon::vticon:

:vticon::vticon:

:vticon:

prometheus
11-02-2018, 09:31 AM
It's from another time...ancient yet future also...specularity shifts over large amounts of moon time especially when father SUN comes to visit it's like he is emotional...


:vticon::vticon::vticon:

:vticon::vticon:

:vticon:

The image loads a bit slow, a suggestion would be not to use png, which often is good for most other stuff in graphics and lossless, but instead use jpg with a compression of 80 will load faster and good enough for showcase on the forums.
Thanks for the history of the moon :)

Kryslin
11-02-2018, 10:59 AM
Ma3rk : To my inexperienced eye, it looks pretty good.

erikals
11-02-2018, 02:58 PM
I switched to a Delta material for the moon object, and that with some matte & luma manipulation into a gradient for surface transparency is getting there. Think I need to kick the volu fog up just a bit or tweak distance settings. In any case, I'm just bummbling along with this so open to better techniques.

Knocked the main enviro light down some as well.

143265

yes, looks good   :)

Ma3rk
11-04-2018, 02:14 PM
Thanks guys.

By an odd coincidence, I came across an actual reference within my own scene.

Items don't seem to like to instance consistantly when FBX exported so I know there's going to be some fiddling. I noticed some gaps in my scene where it seemed a building should be, but there wasn't anything that looked like a church (all the structure names are genereic bldg01, etc.). And ya can't have a proper old Western town w/o a church! And of course it has to be at one end of the main street, and in this case that just happens to be opposite of the Undertakers.

So, I started whanging together a Southwestern church from a Northeastern one. Planning on reworking some the stone work & think some instancing & Bullet "modeling" might come into play. Anyway, mostly working in wire or shaded mode to position & tweek things so finally set up the camera & took a peek.

There's the real moon in the HDR.

143287

... and looking the other way:

143288

They both work so for now I'm keeping 'em I guess. Next chore is to refresh the wetware on weight maps & instancing to add more weeds & dry grass.

BTW, In migrated this scene over from 2018.06 to .07 fairly painlessly. I've had a bit of twitchiness with Modeler, but if you save then sync to Layout then Close the model &/or Modeler before continuing in Layout, it's fine. Been that way for awhile but I've an aging system that I can't fully rule out. Layout crashed once this am when I got up to get more coffee, & it wasn't doing anything. Very occasional Gremlins but nothing that's repeated anyway.

jwiede
11-04-2018, 07:00 PM
BTW, In migrated this scene over from 2018.06 to .07 fairly painlessly. I've had a bit of twitchiness with Modeler, but if you save then sync to Layout then Close the model &/or Modeler before continuing in Layout, it's fine. Been that way for awhile but I've an aging system that I can't fully rule out. Layout crashed once this am when I got up to get more coffee, & it wasn't doing anything. Very occasional Gremlins but nothing that's repeated anyway.

Are you still seeing crashes/instability during switching between Layout and Modeler with .07? Stability-wise I'm still seeing issues synching with Hub on Mac. I haven't really checked whether the Windows-side "app switch delay" issue is fixed, suspect so given release notes, but will confirm later. Alas, decent reliable repro of stability issue with synching on Mac remains elusive.

Scene's looking quite nice, is it supposed to be a "ghost town", or still an active, functioning town?

shrox
11-04-2018, 07:04 PM
One minor thing, there was often two way wagon traffic on a street like that, so it would be wider. Pretty accurate otherwise. (I grew up in Arizona.)

Ma3rk
11-04-2018, 10:04 PM
Are you still seeing crashes/instability during switching between Layout and Modeler with .07? Stability-wise I'm still seeing issues synching with Hub on Mac. I haven't really checked whether the Windows-side "app switch delay" issue is fixed, suspect so given release notes, but will confirm later. Alas, decent reliable repro of stability issue with synching on Mac remains elusive.

Scene's looking quite nice, is it supposed to be a "ghost town", or still an active, functioning town?


As mentioned it's been intermittant. Very stable tonight but not pushing anything either. Keeping a cautious eye open though.

I havne't really decided. Think it's a present day ghost town. Got a couple things to age yet still.

Mostly it's a way of practicing surfacing, lighting etc. w/o much investment timewise on modeling. Been having to to some of that anyway on these particularly the UV's. Got a good workflow now where I can just temporarily apply a single texture in order to see what's going on in Modeler. Some of these need extreme Free Move point dragging in the UV window, coloring outside the lines so to speak in order for some textures to tile correctly or at leas acceptably.

Been waiting a long time for things to work like this w/o too much of a struggle. Ya, some things need TLC still. Suspect new system this coming Spring will open up some new abilities I can't now due to hardware limitations.

Ma3rk
11-04-2018, 10:27 PM
One minor thing, there was often two way wagon traffic on a street like that, so it would be wider. Pretty accurate otherwise. (I grew up in Arizona.)

I thought of the same thing late yesterday in fact. Fortunately, being a digital set that's semi easy to change.

The terrain is still very much a WIP. I'd like to completey redo it but the original has some nice work in that there 6 different texture layers and 5 different masks. Unfortunately, none of them are labled or meaningfully ID'ed other than color, normal or mask. My Knode Knowledge is a bit taxed too. In After Efects, I know how I could combine, layer, mask etc., but with the Nodes I'm missing something. Probably looking for one thing & it's called something unexpected. &/or just making it harder than it needs to be.

At some point I'll try to pick apart the surface as it is in Daz's UI, but that could be painfuller.

prometheus
11-06-2018, 11:35 AM
Thanks guys.

By an odd coincidence, I came across an actual reference within my own scene.

Items don't seem to like to instance consistantly when FBX exported so I know there's going to be some fiddling. I noticed some gaps in my scene where it seemed a building should be, but there wasn't anything that looked like a church (all the structure names are genereic bldg01, etc.). And ya can't have a proper old Western town w/o a church! And of course it has to be at one end of the main street, and in this case that just happens to be opposite of the Undertakers.

So, I started whanging together a Southwestern church from a Northeastern one. Planning on reworking some the stone work & think some instancing & Bullet "modeling" might come into play. Anyway, mostly working in wire or shaded mode to position & tweek things so finally set up the camera & took a peek.

There's the real moon in the HDR.

143287

... and looking the other way:

143288

They both work so for now I'm keeping 'em I guess. Next chore is to refresh the wetware on weight maps & instancing to add more weeds & dry grass.

BTW, In migrated this scene over from 2018.06 to .07 fairly painlessly. I've had a bit of twitchiness with Modeler, but if you save then sync to Layout then Close the model &/or Modeler before continuing in Layout, it's fine. Been that way for awhile but I've an aging system that I can't fully rule out. Layout crashed once this am when I got up to get more coffee, & it wasn't doing anything. Very occasional Gremlins but nothing that's repeated anyway.

The scene is looking great, though I have no real reference memory of such scenery.
A suggestion though..maybe size down the ground textures, as well as the scale/ amount of displacement on the ground.

jwiede
11-06-2018, 12:09 PM
I havne't really decided. Think it's a present day ghost town. Got a couple things to age yet still.

Ah. The only thing that had caught my eye were a couple of fairly large tree/shrub instances in what would be "high-traffic" areas in the street, but as it's a ghost town, that's fine.

I'm less than thrilled with the current preview-less Modeler workflow w.r.t. surfacing, I really think that was a significant misstep on the devs' parts. I understand the reason/limitation that caused that, but strongly feel they needed to find a better solution than to completely drop surface previews from Modeler's Surface Editor. If you've got synching between apps, and you can migrate view frustum data from Layout to Modeler, then you can dang well do the same with a surface preview image.

Ma3rk
11-06-2018, 07:51 PM
Ah. The only thing that had caught my eye were a couple of fairly large tree/shrub instances in what would be "high-traffic" areas in the street, but as it's a ghost town, that's fine.

I'm less than thrilled with the current preview-less Modeler workflow w.r.t. surfacing, I really think that was a significant misstep on the devs' parts. I understand the reason/limitation that caused that, but strongly feel they needed to find a better solution than to completely drop surface previews from Modeler's Surface Editor. If you've got synching between apps, and you can migrate view frustum data from Layout to Modeler, then you can dang well do the same with a surface preview image.

Ya, one would think. Something to look forward to I suppose.