I’m just getting started with Substance Painter, and I’ve run into a baking issue I can’t seem to solve.
I’m working with a fairly complex spaceship model exported from Blender 4.4 into Substance Painter 9.0. The model has a lot of hard edges, and despite several attempts, the entire mesh shows up purple during baking — which usually suggests missing seams or bad hard edge setup.
Here’s what I’ve tried so far:
• In Blender, I manually marked some sharp edges.
• I attempted Auto Smooth and also tried the Edge Split modifier.
• I unwrapped the UVs properly and recalculated normals.
• During FBX export, I enabled Apply Transform, Apply Modifiers, Include Normals, and Include UVs.
• In Substance Painter, I confirmed that normal maps are imported correctly and used the standard PBR Metal Rough shader.
• While baking, I disabled Average Normals, enabled Use Low Poly Mesh as High Poly, and tested both with and without a custom cage.
No matter what I try, the model appears fully purple during baking, or only the hard edge areas are purple depending on the test.
I’m looking for a Blender 4+–friendly workflow to mark or export hard edges in a way Substance Painter can correctly interpret — ideally without having to manually flag every edge.
Any help or tips would be greatly appreciated. Thanks!
My process :
First on Blender after auto-smooth, remesh, normal check etc… I Do
Select sharp edge in edit mode (I play with the angle to do the best selection)
I do mark sharp and mark sean
Export in FBX
In substance side I do create new
F8 backing end… All my hard edges have no seam, purple line correspond to hard edge mark sean and mark sharp in blender :
You misunderstood the whole baking things. Baking low poly onto itself will result in perfectly “flat”, i.e blue (not purple) normals.
You will get some curvature and AO though, but not any details in the normals since they simply doesnt exist.
Haha, indeed, I’m way off base as a complete beginner!
So if I understand correctly: by using a high poly mesh over the low poly, it serves as a baking source for the low poly. Then I can texture using the baked maps on the low poly.
In this case, I still see “missing seams on hard edges” on the high poly mesh, but I guess it doesn’t matter, right?
Because the actual projection and UV stitching will be done on the clean low poly in the end.
Is that the general idea? Can I work with something like this without any problems?
I got a bit confused with tutorials that insisted on the need to not have these purple lines… But on the low poly model that will later be used as support if I understand now.
Thats counter productive. It will add aforementioned sharp edges in places that there are not uv seams.
In baked workflow Your model have to be smooth shaded, and You can place sharp edges only in places that already have uv seams (but ont every uv seam have to be sharp edge).
Notice that on purple line there is now artifact
because normal map that is texture on 0cm distance have to transition from one “color” to totally different" color, so if there is not distance to do so on texture there will be artifact
