Animation export to Unity

[Mikhail_Alexeev]

Hello everybody!

I have a simple grid animation like this:

The animation is driven by a $F*0.001 expression in mountain node offset channel:

Is there a way to:
1) Loop this animation seamlessly
And the most important:
2) Is there a way to export this animation to Unity?

If yes, what format is better for the task and what export/import settings should I use?

Thank you for your time.

[LaidlawFX]

As far as making it loop, in the Houdini 16 game shelf there is a create loop shelf tool you can use. As an alternative stitching method, I have one one on orbolt that forces the ends to overlap.

http://www.orbolt.com/asset/LaidlawFX::BlendLoop::1.0

As far as exporting it to unity there are three methods, two I would recommend however. The first i would not recommend is blend shapes in unity(not worth it).

Moving onto better methods, lol, you can use fbx where you assign a bone per a vert and transfer the position information to the bones from your rest position. This is a very traditional method, as you can import it via the normal fbx pipeline. 

The alternate more efficient, but at this current moment takes a bit more effort, is to do it by vertex shaders i.e. fancy displacement shader. On the game shelf there is a tool called vertex texture animation i believe. This is currently only has the unreal shader provided, however, you can easily mod it for unity. If you wait and poke SideFX they will develop the unity shader for this. What this method does is encode each transform per a joint into a texture based data format. Then you export the geo via fbx, the transform via this exporter as soft, and you can copy the unreal shader from the tool mod it for unity and apply the shader in unity. The link to that odforce conversation.

 

[Mikhail_Alexeev]

Loop tool worked perfectly, thanks.
As for the animation - I think for now I'll stick with the quickest and simplest solution - FBX export, 
can you describe the most suitable process for assigning bones to  mesh like this step by step?
What FBX export settings should be used, baking, skinning etc? Thanks again

 

[LaidlawFX]

I unfortunately don't have the time to create an example set up for the fbx workflow at the moment.  So hopefully some one else can help you on that. If you look up basic rigging and fbx rbd export tutorials it's not a terrible setup to do. An alternative if you are familiar with another package like Maya, is to export via fbx with with out a rig as a geo cache or as an alembic, and then rig in the other package. In general you are assigning a bone to a point/vertex. With the static geo, or rest position, as your T pose. So you can iterate over each point attach a joint(usually via python or another script language), and then bake the position transform of the deformation as a key frame on to the T pose, minus the difference from the default position. If you forget to subtract the difference from the T pose, your T pose should be at Zero. Hope that helps.