Hello all,

A long time ago I've created a very complex tank model within SI, which I recently imported in Houdini and which I would love to animate someday.
The problem that I face now is that I need to group or combine certain components such as running wheels or rubber tyres in order to create one UV Layout that could simplify subsequent texturing in Substance Painter (cue: UDIM tiles)

Since every wheel needs to have its own independent radial arm, I can't find a way to create one combined UV Layout for all running wheels, tires, tracks without changing the hierarchy. I guess can't merge the components (and assign one UV Layout) and break them apart later on, because they won't propably keep their original position as soon as I reassign/parent them to their particular radial arm null.

Is there maybe a way to group all moving objects (wheels, tires etc.) without merging them and assign a UV Layout to the this particular group?
If not, what would you do, if you had to texture hundreds of more or less identical objects that all are supposed to have individual textures made with Substance Painter?

It wouldn't be a problem at all, if they were static objects, but since they will rotate or move later on, I think I can't just merge them.

Any ideas would be highly appreciated! Thanks for your help & time & best regards

Hi, I expect there are other methods but I've attached a hip file of one option you could look into.

This method should work if you are animating at object level. If you are animating at sop level, you could use a rest position for the UV or animate after layout.

Use an object merge to gather all the geometry you want in one UV (or Texture Set for Substance). Then use another object merge to transfer UVs (and mats if you like) back to the original geometry.

I've shown two sets of objects and each set is combined into one UV and Texture Set. You can export this to Substance as one model split into Texture Sets based on the material names.

Rob

Hello Rob,

thank you very much for your response, help and effort!

I'm not quite sure how I will animate the tank at the end, since the movements should be as realistic as possible, and maybe I will have to animate the wheels etc. on sop level, but your approach is absolutely helpful (to understand how things work in Houdini).

Thanks a lot & best regards