View Full Version : shading cloud particles

03 March 2006, 10:34 PM
hi all, i am putting the 3d cloud texture into the color channel of cloud S/W type particles.

it seems to work fairly well, i assume the particles are gonna 'swim' through the texture, but i assume it is supposed to work this way.

it looks fairly decent.

so my question, of all the different little things to adjust, such as amplitude, depth, etc, what can i use to slow the frequency of the billow action so it is slower. have tried a lot of things but it is just way to fast for me.

thanks for any help ahead of time.


03 March 2006, 11:09 PM
All procedural 3d textures have an option called Local, found under Effects in the Attribute editor. Turn it on and your particles will stop swimming through the texture. This only works in software rendering unfortunately, and not Mental Ray (there is a way around it, but it's a bit complex, see here (

The Cloud texture isn't your best choice if you want the texture to billow, since it doesn't really have any parameters for animating the noise. The cloud texture's noise is, like most other 3d texture noises, a 3d noise, but to get real animatable noise the noise either needs to be a 4d noise, or "cheat" animated noise, and the cloud texture doesn't fulfill any of these prerequisites. If you want real animated noise, you're much better off with Volume Noise set to the Space Time noise type. It has a Time attribute which you can keyframe, or better still, control on a per particle basis using a Particle Sampler Node.

Of course, you can also get animatable noise using the built in noise of the particleCloud shader (it will only show in the transparency though) and setting the Noise Anim Rate to a value other than 0. A value between .01 and .1 seems to be good for most situations, smaller and you'll hardly see it changing, higher and it will swirl like crazy.

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03 March 2006, 11:09 PM
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