Hello all,

I was wondering if anyone here knew of some good resources concerning Houdini 11, FBX and the Unity game engine. I wish I could be more specific as to what aspect I am looking for but I can not be as I don't know what it is I don't know.

I would hope that someone here has used the FBX export in H11 to get assets, bones, cameras, etc. etc. into unity 3.x. If so could you all write some elements of your knowledge here, please?

I would really like to use Houdini as my primary asset generator for export to unity and I feel like I am just stumbling around. For instance: I have a carriage whose wheels are animated inside the node but it's apparent linear animation (travel down a road) is at the node's transform level. Upon exporting unity seems to only read the node level transforms and not any sub-level animation. While I can deal with that it is a “gotcha” and I was hoping to find here other like-wise “gotchas”.

Any help is most welcome.

Thank you

I haven't tested Unity's FBX import specifically, but I can help explain why, in all likelihood, animations at the SOP level do not import into Unity. The FBX exporter sees each geometry node as a single geometry piece. When a parameter on the geo node itself is animated (for example, translation or rotation), the FBX exporter sees an animation curve and exports it as such. However, when anything is animated at the SOP level, all the FBX exporter sees is geometry that is changing over time - it cannot go down to individual SOP level, since no such concept exists in FBX. Thus, it exports these using vertex caches, which essentially store a snapshot of the entire mesh at each frame.

These are probably not supported by Unity's importer, since I don't think it makes much sense to use these in games. So a general rule of thumb for FBX export would be to animate everything at the OBJ level instead of in SOPs.

The other thing that I would test for conversion is bones and skinned meshes - traditionally, these have seen the most problems among all file formats that carry data between separate applications.