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Houdini to Unity - configure vertex animation textures


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Need help in configuring the new vertex animation textures SOP from the latest Game Development Toolset


In particular, not sure what I should be using as my Export node. My .hip is from the Ocean tools Masterclass. I've simply added the GameDevelopmentToolset OTL's to my Houdini install.

Shouldn't my BBOX MAX and BBOX MIN automatically populate with values? Can anyone help?


Following these instructions for importing fbx and textures in unity






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ok almost there! Issue was I needed to use Fluid as the Method before hitting Render on the Vertex Animation SOP.

2 remaining issues


1- in the attached obviously not enough resolution. How to determine the accurate resolution? Is it simple the number of polugons in the original grid?


2- Frame rate

Once brought into Unity I am playing back at 24 fps however the apparent frame rate is much much faster!!Why is this happening?




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Hey art3mis, 

The resolution for the fluids is numberOfTris*3 on X and numberOfFrames on Y. With the caveat that if you have more points than pixels on a row it will break the geo up in 2 rows. So if you have 1024 points and 100 frames, and you choose your texture to be a 512, you will have 512x200 sized texture. 

Resolution starts to fall apart around 6k pixels, so I try to keep it under that size in general. 

I'm not sure about the Unity shaders, but in Unreal I usually have to change the play speed to 1/3 to get something that feels right, so .33. I'm sure there's some math that I need to figure out for a 24fps source animation being played at 60fps in a game engine, but .3 felt good. 

Hope this helps

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Thanks. Great info!! But still some confusion about your explanation and how it relates to the 2 parameters, Target Polycount and Target Texture Size.

1. If my source grid is 100 rows by 100 columns does that mean my Target Polycount should be 100 x 100 or 10,000?

2. The only other parameter is Target Texture Size. If my number frames is 240, what should this value be?

3.  When you say resolution, do you mean Texture size?


and lastly

4. I see an option to export a color map. Would this be more or less the same as an albedo or diffuse map in a PBR render? Is there an example with this option?


Any help appreciated!



Edited by art3mis
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