Does the ambient cloud setting dampen the details of the render?
What light settings would heighten the cloud details? I'm thinking I shouldn't use Soft Lighting, if I want stark details.
Quote from: calico on September 12, 2008, 11:10:46 AM
Does the ambient cloud setting dampen the details of the render?
What light settings would heighten the cloud details? I'm thinking I shouldn't use Soft Lighting, if I want stark details.
If I remember correctly, I think Matt said the soft shadows don't effect the clouds anyway, but I could be wrong. Perhaps a second opinion would be good.
I think I remember it does work, but slightly in clouds. Ambient doesn't appear to do anything major, but maybe I need to work it in tandem with other settings (I don't know about) to get the ambient light to shine. Literally...and everything.
I'm finding that Fake Internal Scattering is pretty powerful for showing details.
Quote from: calico on September 12, 2008, 01:49:45 PM
I'm finding that Fake Internal Scattering is pretty powerful for showing details.
Exactly.... or hide them :)
This option can help in bringing the details forward or hide them where there are shadows on the clouds.
Anyway.... I don't fully understand your question, but I don't think the ambient setting would lower the details on the clouds if that is what you mean? It will only make the cloud brighter. I think it is like a fake way to give them more light or something like that.
- Terje
Thanks guys. I think sjefen is correct.
Ambient is simply an overall colour that adds to the shading of a cloud. It's a convenient way of adding brightness to the overall cloud layer in it's simplest application, but can be used to make them a solid colour if you switch off any lights (including the sun) and whack up the Ambient colour to say pure white. It's a great way to make RGB ID channel masks for VFX needs (pure red, green, or blue for instance), by making one layer pure red, another pure green, etc. The RGB channels of the render can then be used to split each cloud layer into separate tweakable elements. The same can be done with the Atmosphere, and even Surface Layers.
JimB, this sounds like more experimentation to clearly understand this.
Have an example from real life for us to understand how this might implement some visual effect?
Set up two cloud layers. Switch off the Sun. Go to each cloud layers' Tweaks settings and make one Ambient colour pure red, the other pure green. Go to the Atmosphere Tweaks tab and make the Ambient colour pure blue. If you have a terrain set up just leave it unlit and therefore black. Render and save a frame (switch off shadows and GI). Load the frame into Photoshop (or its equivalent) and go to the individual RGB channels, where you'll see each cloud layer can be isolated as well as the atmosphere, and the terrain can be picked out because it's pure black.
Example to follow.
Quote from: calico on September 12, 2008, 08:29:31 PM
Have an example from real life for us to understand how this might implement some visual effect?
There's a brief shot or two in the Digital Domain "making of" video for their Motorola Pebl spot - http://www.digitaldomain.com/ > Commercials > Behind the scenes.
There's also a brief description of the technique here - http://forums.odforce.net/index.php?showtopic=3532&st=0&p=23521&#entry23521
@JimB - I can't wait to try this and open up yet another avenue of how things work. Thank you. [EDIT - Just tried it and it makes sense. Now, to figure out what to do with it...]
@Moose - I read it and understand it (the second link), but assimilation is not essential...yet. ;D I'll keep at it.
If Moose's links are the ones I think they are, that's a completely different technique for a different purpose. The one I outlined is to essentially create three (or even four really) masks in one image, so individual cloud layers can be graded differently, and also other elements slotted between them. The DD thing is so that lighting can be tweaked at a later stage during compositing using a render of directional lights. Similar principal but completely different results. ;)
Quote from: JimB on September 14, 2008, 07:19:52 PM
Similar principal but completely different results. ;)
...and it's all over my head completely at this moment. I did try your method, however and understand it to a point. It'll take some actual working with it to find a good application for it.
Ambient in the clouds works like ambient light settings in any other 3d app - it's a very common and fairly universal function.
http://www.webreference.com/3d/glossary/ambient.html
http://wiki.blender.org/index.php/Manual/Ambient_Light
So in the case of clouds it basically provides a way to set a "base", non-directional and uniform light level. Because if its uniformity and lack of directionality it will not produce particularly realistic results and its use is limited.
To increase apparent detail I'd suggest either higher edge sharpness or density in the cloud layer settings, or simply higher contrast in the renderer settings or post processing. You might also need to adjust your cloud shape noise function to increase detail. There is really no one solution to a "detail problem" as it depends on the source of the issue. Some visual examples would help here in determining exactly what you might need to adjust. That being said nobody yet knows how to create "the perfect cloud", so your own further experimentation is useful.
- Oshyan