I had to run through multiple Mixamo animations to see how the cloth physics would react with the vertex weighted sections. I set up this test scene with various movement types, which really helped identify problem areas in the cloth simulation.
Each time I thought I had it optimized enough, I’d import into UE5 only to get hit with that same error. The cloth generation would fail instantly. It was this constant back-and-forth process:
- Reduce poly count in C4D
- Export to UE5
- Try to generate cloth
- Watch it fail
- Back to C4D to optimize further
Had to be really strategic about where to reduce polygons while keeping enough detail for the patch seams. Those areas where the red and blue sections meet were particularly troublesome – I needed enough geometry for the cloth simulation to work but too many polys would create those degenerate triangles UE5 hates so much.
Working with Octane’s dirt texture node seemed like a good approach initially for generating the vertex map – the idea was to automate the vertex painting process, I’d set it up to accumulate at the fabric folds and seams. However, I never ended up following through with this idea since I couldn’t find a way to import the texture or even use vertex maps in the cloth painting.
Here I boole the mesh so that it is hollow, allowing me to use cloth physics in a way that the cloth hangs off the body instead of starting inside it and bulging outward.
The polygon reduction actually ended up working in my favor here – that lower poly count created these more angular, almost crude transitions between the cloth sections that really enhanced the horror aesthetic. You can see in the viewport how the simplified geometry still maintains those key patch divisions while giving the cloth simulation something it can actually work with.
Working with the character rigging required some careful adjustments to prevent those classic cloth collision issues. I had to modify the bone structure to create better collision volumes – basically giving the cloth simulation more accurate surfaces to interact with. This was crucial for preventing that annoying cloth clipping where the fabric would phase through the body during animations.
Going back to Cinema 4D to tackle the UV mapping was essential to get that burlap texture working properly across the patches. The initial UV layout was causing the burlap texture to stretch and distort in weird ways, especially around those crucial seam areas where different sections meet.
Adding grunge layers to the burlap texture really brought out that weathered, unsettling quality I was after. Used a combination of darker patches and worn areas to suggest where the fabric’s been stressed and damaged – particularly important around those sewn sections where the patches meet. The material variation helps sell the idea that these pieces were scavenged and roughly stitched together.