Importing mesh from Blender into SP

[Al Bankowska Bankowska 0]

Hey guys, I have a project I have done in Blender that I want to texture in SP. It's a detailed model of bicycle for close up renders, and consists of 70 different objects (pedals, brakes etc.).

I'm quite new to SP so I watched a few tutorials on Youtube but received conflicting and incomplete information for how to prep, export then bake the meshes (certainly something this complex with a large number of objects).

So far, in Blender I have made low poly (1.5 million verts) and high poly (7 million verts) copies of each object, named them the same only changing the suffix _low/_high respectively. I UV unwrapped the low poly meshes and gave them all the same material (this feels wrong to me but that was what 3 different sources advised). Then exported both low and high as separate FBX files (I didn't unwrap high poly).

(I also attempted to use TexTools addon to create an ID map for the various objects but this didn't quite work as it should)

In SP I created a new project PBR Metallic Roughness (alleg), 4k, the other options here I am unsure of. I have this message in the corner I don't know what it means but red is usually bad..



... but generally the mesh looks OK. When I then bake...



... I'm getting a few artifacts like this...



It's now divided into 3 objects (I'm also unsure where this "TT" is coming from)...



I guess at this point I'm a bit lost, I don't know if I should divide it by object (70) or perhaps by texture (probably only 8 or 9). I'm not really sure what the best way to handle this is, it's quite different from how I would texture in Blender. But I have used SP a bit and know that it is required to take my texturing to the next level. The actual texturing I think I can pick up without too many problems, it's this whole process that is a problem for me.

Any help would be greatly appreciated.

[CAGameDEV]

I wont address the baking artifacts because I would need the meshes to show you how to fix them aside from general information which has been posted all over this forum along with Polycount.

If you're working on a close up render you should be looking into UDIMs as I doubt using a single 4K map is going to be enough due to the overall texel density. Using different MAT IDs really should be done in the event you either are going to use another shader for that set, or if you're not using the new Painter version and cannot Paint across UDIMs, or you need to isolate pieces with the intent to merge them after (you're not using Painter 2021 with the option to isolate by mesh).

I would set up everything under one MAT ID, and set a texel density that will be appropriate for your render piece, then utilizes multiple UV tiles. You can keep objects split which is fine, but I would figure out your UV tile setup so you can get a good quality render done.

[Al Bankowska Bankowska 0]

Thanks for the reply CA.

The baking artifacts I will worry about later when I understand everything else, they seem to change places and severity each time I bake it.

I have a rudimentary understanding of UDIMs now (quick study), so separating the different parts of the bike into different UDIMs based on their material (chrome, rubber etc) should solve not only my resolution issues (I discovered that was a problem as well) but seperate/create the appropriate texture sets in SP? Am I able to create 8k UDIMs (for larger meshes) and use them in SP as well or does it max out at 4k?

I like the MAT IDs as a concept so want to incorporate them into my workflow certainly, I do have the latest version of SP as far as I know, though it is the student version so perhaps there are differences...



Can I use this to paint across UDIMs?

Texel density is my homework for tonight, I understand the concept but have never needed to apply it to a model before. To be honest I spent years perfecting detailed modeling because I was a bit intimidated by everything connected with texturing, but now is the time.

[CAGameDEV]

You really don't need to worry about MAT IDs for the loaded in mesh. Unless you're using another shader or these are different objects and you have a reason to split them up.

You cannot paint across Texture Sets, but you can across UV tiles within the same set.