updating a multi-mesh fbx and scaling with physical size and instancing.

Report · Jul 25, 2023

When I export a full character as an fbx and then make a change to part of the mesh (eg adding buttons or buckles to the shirt with a small amount of extra uv space used) the patterns I have applied to both the pants and the shirt using physical size and instancing, which were a consistant size across both, break and become larger on the shirt. I expected the scale to change when I updated the mesh but I would have thought it would have been consistant across the entire model not just part. Only updating the scale on a single part/material breaks all instancing with physical size as you cant adjust the tiling. Changing the project physical size from mesh internal scale to a custom unit does not help either.
How can I iterate on my mesh and keep the tiling consistant using physical size?
Thanks

Report · Jul 26, 2023

Hi @Will240186381gjg,

Thanks for the message.

First of all, iterations aren't currently a strenght of Substance 3D Painter and we don't recommend to use a workflow based on iterations with Substance Painter. With that being said, the reprojection feature is here for this type of cases and should work as expected.

I'm a bit surprised the physical size breaks when reimporting the mesh. How did you apply the material? Are you using the same file format (.OBJ, .FBX, etc.)? If you add a new material using the physical size, does it tile as it should or does it stay inconsistent?

Let me know,

Cyril Dellenbach (Micro) | QA Support Artist | Adobe

Report · Jul 26, 2023

Thanks for the reply Cyril,
Unfortunatly part of any game development pipeline involves a lot of iterations and adjustments to both the mesh and the textures. It is very rare that the mesh we start texturing on is the final mesh. And mesh changes dont just mean uv changes. These involve proprotion changes, swapping out parts and general mesh adjustments.

I applied the pattern via a fill layer and set the scale to physical size. I then copy that layer and paste it into another material layer as an instance. I tired adding a new material on this mesh and it remains inconsistant. Its almost like the mesh scale is broken for the project. Same things happen if I use an instance of that pattern or simply copy and paste it into the scene.

I'm not sure but one thing that could be effecting it could be the texel density of uvs. We dont always have consistant uv scale. For a shirt for example, we may scale up the buttons so that we have more detail on these parts or scale down the inside of the sleeves or other inside areas that are mostly hidden from the camera. One of the things that really effected the scale drastically was adding some buttons to my mesh. they were tiny but the uvs were scaled up slightly. They were overlapped so didnt take up any extra space. Even though they wernt using the pattern, they still effected the tiling scale on the rest of the shirt.