Zbrush is distorting my happy UVs

Banjo_Bill

Hi, I'm new to the forum, but I've been using Zbrush for awhile. I've run into this before, and I can't figure it out. I made a fort building set. It's 6 pieces, and they have high frequency detail and textures on them. I make a UV map in UV Master. That's fine. I use multi-map exporter. I get my Normal Maps and my Bump Maps and they look fine, but when I get my Texture maps (and AO and CV), they look rounded. Literally, where there was a sharp corner, Zbrush has subdivided and smoothed my UVs. The texture is all stretchy, and it doesn't cover the model.

It's like Zbrushed washed my Textures in Hot water and they shrank.

BUT... like I said, the normal and bump maps are fine.

Iffy parts of my work flow:

1. This model is not a solid block, it's more like a plane. You could take each piece and flatten them out.

2. The Set is all one OBJ. My secret plan was to make a single UV map, and then export my OBJ and break the poly groups into smaller pieces latter.

3. The separate polygroups are not welded together.

cryrid

In zbrush, the normal/displacement maps are baked at the lowest level to capture the differences between high and low, while polypaint-based maps like textures are created at the highest level in order to capture the detail. This is why those maps would be rounded, as zbrush will likely be set to smooth UVs. There's a ReUV option in the MME plugin which might reapply the original UVs pre-smoothing, but I've never baked this way so I'm unsure how well it will work. Personally I'm an advocate for baking your maps externally (usually xnormal or subtance painter) so that you can have way more control over the result without any need to share UVs or even topology between mesh resolutions.