Some problem about new Vertex animation Tool

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Joined: 10月 2016
I have seen Vertex animation tool presentation on twitch, it's very impressive.
One part of that presentation, converting houdini flames to vertex animation in UE4 with color.
I can't figure out how it works.
Is that using “Attribute from Volume” extract heat or temperature information from flames volume?
The flames color in UE4 is very smooth, not like vertex color.

Hoping lkruel can share some ideas behind scene.

thank you.
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Joined: 11月 2012
Hey FoxHuntd

Here's an updated HDA that should make things a bit easier to work with []

So there's 2 ways of doing the coloring effect. One is just using a flat color and doing a fresnel on the Opacity to fade the interior of the flame.

The second way is to actually export the color data from the simulation and read it in the shader. What I've done before is export the temperature and then use that to drive a ramp texture, which gives me a nice smooth value.

I'm also doing some manipulation of the data after the attributeFromVolume, I have a pointWrangle that does some basic pow() and multiplication on the color to mess with the contrast and intensity, as well as an attributeBlur to soften it a bit.

Hope that clears it up and let me know if you have any questions!

attribute_volume_blue.png (1.0 MB)

Luiz Kruel
Senior Technical Artist
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