Hi all!

What is the proper way to export a skeleton mesh from Houdini to Unreal?

AFAIK the Houdini Engine plugin for Unreal (even v2) can't do skeleton meshes, leaving us with the FBX format. I just want to export a very simple, custom skeleton, just a few nodes/"bones".

The problem I have is that the imported skeleton gets a scale value of 100. Visually, everything looks correct in Unreal, though. AFAIK having a scale other than 1 can lead to subtle problems later.

I use Houdini's ROP FBX Character Output node. The ROP has an option to Convert Units from meters (Houdini) to centimeters (FBX/Unreal). If I turn this on, the skeleton gets the correct size on import (but a scale value of 100). If I turn it off, the skeleton gets 100 times too small (but a scale value of 1). This has the same effect as turning it on and then transforming the scale to 0.01 on export. Or changing the scale to centimeters in Houdini when exporting.

Thanks!

I figured out a solution.

I have to set the units (Hip File Options) in Houdini to centimeters (the default is meters), which is what Unreal uses. But then the model becomes 100 times too small. Fortunately, I can use a transform node to set the Uniform Scale to 100 before starting on the skeleton. I found it awkward to try to model with such large values.

I then have to build the skeleton in centimeters, using values that are 100 times larger than when I model. I can't scale the skeleton, either on export or on import, as it will then get a scale value in Unreal.