View Full Version : Fluid Attribute Maps

03 March 2011, 03:49 AM
Hey all,

I've been trying a few techniques for making clouds in fluids, and I've decided to use the fluid attribute map to get the basic density and shape of the cloud and then manipulating it a bit with fields for the final look. Everything works great in tests when the container size is below 100 in all axes, but as soon as I scale the container up to fit the scene ( around << 70000 , 20000, 70000 >> ) all the luma values in the image shoot up to 1 and suddenly there is no variation in the density and the cloud loses its detail. Is there a workaround for this? If anything I could just scale the scene down but I'm confused why scaling up a container would influence how Maya interprets the RGB of an image.


03 March 2011, 12:47 PM
I don't have the answer to your question, but usually what the people do is scale down the entire scene, so in the fluid you can work with much more normal values

edit. Sorry I told you something you already know.


03 March 2011, 07:52 PM
Not sure if this will help, but in some cases increasing the near clip on the camera helps the rendering because the transform space is less extreme.


03 March 2011, 08:02 PM
thanks for the replies, I ended up just scaling the scene down and things are working fine. Speaking of attribute maps though, is there a way to interpret the luma of an image to affect the depth of the density? Right now I'm just using a script that clips the image down to a designated depth and then use fields to break up the middle to make it look more natural. Is there some sort of central gradient or something that could be applied, where a luma value of 1 would set the depth from the front to the back of the container, and a value of .1 would stay relatively close to the center of the container?


03 March 2011, 10:30 PM
Under the render stats, enable Shading Samples Override (1,1) and then disable Volume Samples Override.

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03 March 2011, 10:30 PM
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