Peach Open Movie: Volumetric Clouds

Post by **ton** » Wed Nov 21, 2007 6:44 pm

zaghaghi wrote:I started coding, first a gui about where you,peach team, want volumetric material, and what options do you suggest to be here?

I find this a difficult approach... you might better first design or define a system, and then design the UI for it.

zaghaghi · Post by **zaghaghi** » Thu Nov 22, 2007 11:06 am

ton wrote:I find this a difficult approach... you might better first design or define a system, and then design the UI for it.

you're right, i stopped coding like that, but i have a question that asked it at previous Sunday meeting, that is, should Blender do things like cloud generation?
I think that blender is a general purpose 3d modeling and it's may not necessary to do things like cloud generation, some single purpose applications like bryce do this, but i think we should make for example some volumetric materials, that can be used by artists for making clouds.

by the way i think that for a simple start i can add volumetric halo to current halo system, that generate random halo points in mesh, with some parameters like density.
or don't start coding, and make a specification and design first.

Caronte · Post by **Caronte** » Thu Nov 22, 2007 3:40 pm

zaghaghi wrote:...that generate random halo points in mesh, with some parameters like density.

This method can be done actually with the new particles, but I don't think thi´s a good way (slow and hard to setup).
I think we need a good volumetric shader, instead of use multiple overlapped halos.

LetterRip · Post by **LetterRip** » Thu Nov 22, 2007 8:40 pm

zag,

a more generalist approach is certainly desireable - ie volumetric particles that can, among other things, be used for clouds would be quite useful. Your question wasn't quite clear at the meeting.

LetterRip

grafixsuz · Post by **grafixsuz** » Wed Nov 28, 2007 6:42 am

@zaghaghi: how are things going with this project? I haven't heard about this for a while.

RipSting · Post by **RipSting** » Tue Dec 18, 2007 1:05 am

Realistic clouds in blender is certainly possible. No particles, no ray-tracing. Just camera-tracked planes with a few layers of procedural textures. Render time on my quad core at HD resolution is 30 seconds. The downside is that you can't interactively see your clouds, you must render to preview.

Mostly cloudy

Sparse clouds

Overcast

A monkey in the clouds

Technique

Watch the video at http://www.youtube.com/watch?v=ubUiD6qRYwk

There are 3 texture layers. 1)Cloud color and alpha 2) A blend sphere that smooths the edges of each individual billboard. 3) A "cloud darkening" blend that darkens each billboard depending on its Z location. I created the grid by subdividing a cube and then removing doubles with a high limit value to evenly space the points. Then I created one billboard object and dupliverted it. Upon setting dupliverts to real, you can make them all track the camera. The camera tracking step is the most important, as it lets you view the clouds from any angle.

Download the source at http://www.curiousexistence.com/blender ... clouds.zip

Cognis · Post by **Cognis** » Sun Jan 13, 2008 11:36 pm

Hi. I don't belong here, I am just one of the peons of the minor league out from BlenderArtists. I just wanted to add a URL that might (or might not) provide a quick and dirty way to do volumetrics:

http://www.digitalartform.com/archives/ ... ple_v.html

It calls it faking, but from what I have tried, you can do mists, clouds, fogs, even thick smoke plumes, just by varying a few things. You can use it already in Blender with a simple Composition Node thingie. I don't know much about the deeper arts of Blender coding, but that makes me think it would be far easier than doing it from scratch.

And it does not require hundreds of planes, either

Caronte · Post by **Caronte** » Mon Jan 14, 2008 3:32 pm

Thi´s the same as the Mist in Blender WORLD window (very basic)

The examples RipSting showed, while not perfect are far better.

JiriH · Post by **JiriH** » Mon Jan 14, 2008 10:32 pm

Maybe these quite new thesis may be useful for coders:
http://www-evasion.imag.fr/Publications/2008/BNMBC08/
http://www-evasion.imag.fr/Publications ... clouds.pdf

Examples:

http://www-evasion.imag.fr/Publications ... _light.avi

It is real-time clouds rendering so maybe inspiring for really fast off-line rendering. Even more objects can cast shadows on the clouds, and clouds can cast shadows on other objects and on themselves. Authors are students from Grenoble university, maybe they would like to help Peach coders.

PS: Thank to Cybor Dragon from BlenderArtists for this hint.

blaize · Post by **blaize** » Tue Mar 04, 2008 8:43 pm

Ofcourse i know clouds wont be added for Peach, just thought i would add this link. (did a quick search and didnt finf it being poster before)

http://www.gamedev.net/columns/hardcore/cloudrendering/

Ofcourse not as impressive as the one poster above, but since everything is explained pretty well (it seems) it might be easier to implement. (things can always be improved)

RipSting · Post by **RipSting** » Sat Mar 08, 2008 6:50 pm

I've taken it upon myself to code my volumetric cloud solution.

Refer to the topic at blenderartists.org - http://blenderartists.org/forum/showthread.php?t=118973

Narodny Geroi · Post by **Narodny Geroi** » Sat Feb 21, 2009 5:33 am

Hello guys,

Recently, I developed a technique to fake volumetric clouds using Subsurface Scattering and Nodes.

Here's a link to a document explaining the technique in detail:

http://www.archive.org/download/FakingV ... dNodes.pdf

I hope this can be useful for someone.

Greetings

Blender.org

Peach Open Movie: Volumetric Clouds

Cloud Generator