Baking texture from reimported model onto original & decimated models

Development Asset Creation
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1

I have a question regarding the flow of operations needed to decimate and texture a model which was previously slightly fixed in other DCC after being captured. Namely, these are my steps:

a) scanning and processing the model in RC
b) exporting textured as .fbx
c) fixing missing / poo quality geo parts with sculptris pro mode (upmeshing) and xtractor brush (cloning) to fix those parts (like bottom-like parts of a rock) inside of ZBrush
d) exporting back to RC to decimate it, since ZBrush can decimate, but unwrapping million poly models is a mistake there

Now, I have a problem after re-import in RC. I import the model inside the same component using import model. I then want to unwrap it and texture (HP version), and also decimate into MP and LP version (respectively, 2 million, 200k, 20k).

First problem is when I want to texture the model (models from ZBrush have vertex color info only and are like 20 million tris large) → when I texture, it messes up the parts that were “hand” fixed in ZBrush. Does texturing take into account initial point cloud from the photogrammetry? What if I want to texture from the largest size model (say 20 million) unto 20K mode FROM VERTICES not POINT CLOUDl? Do I have to use the Texture Reprojection option? But how? I want to reproject from 20 million vertex cloud (which was imported as fbx not coming from scan images) onto the texture, then same for lower count models, so that 20K model, for instance, has super detail texture.

Thank you in advance

2

Hello enquel, please check this tutorial about texture reprojection in RealityCapture: https://www.youtube.com/watch?v=6fQjL0EQIfs&t=4s.
I suppose the best option is to use textures created in RealityCapture. Have you tried the texture reprojection from imported model to a wanted one?
Texturing takes the aligned images to the account, not a point cloud.

3

“Texturing takes the aligned images to the account, not a point cloud.” → yes but eventually it takes the input data not the re-imported model, yes?

The problem is, the model I import has only vertex color info (too high poly to create texture data in ZBrush). What I basically want is to bake that vertex color data (from imported model) onto texture right in the RC (due to its fantastic unwrap). Can this be done with texture reprojection or otherwise?

I can try to unwrap the imported model in RC, export it (again) to ZBrush, and there project color data info from older (non-unwrapped) model onto the newer unwrapped, but it is a lot of DCC juggling at this point and I hoped to avoid it.

4

I suppose if the texture is backed and there are no UVs, then the texture reprojection won’t be possible.