Mudbox - problem with terrain UV Thread

Hi, I'm having some - I guess - simple problems with my Uvs and a diffuse texture, and I can't find any info that worked for me.

Here's what's happening:

This is a 512x512 XSI units terrain, originally subdivided in 8x8. It has a UV map with the coordinates XZ and is exported as an Object. After opening it in Mudbox, I create 8 detail levels, so the mesh has a little more than 4 million polygons. After I apply the diffuse map (for testing), it shows fine on levels 1-2, but anything higher and I get this blank strip on the left side. Like there is stretching happening on that border, on that row of tiles.

Of course, polygons aren't flipped, and I tried rebuilding UV maps for every new detail level. I've been working with World Machine and the displacement map fits perfectly and works. (It's obviously not applied in the screenshots) Just when I get to textures it all gets stretched, and I can't seem to find a workaround. The problem must be quite simple and can probably be solved by someone more experienced than me. I planned to work on this map all weekend and most of next week, so it'd be great to get going again quickly. Any help is appreciated, thanks in advance!

This is the UV view from Mudbox.

Edited by: SinKing

Weird. But I must ask:
Why do you need a UV-map for the highpoly?
Make a lowpoly version of the mesh (512 x 512 xsi units) and UV-unwrap that one. Then just bake the normals from the highpoly onto the lowpoly.

You can use an early subdivision (like 1 or 2) as a lowpoly. Just export that subdivision, move up to 8, import the lowpoly and then bake the normals to it. If the UV's are fucked then just unwrap them again.

Edited by: Nightshade

Well, the Highpoly really is the Lowpoly with 7 levels of Mudbox subdivision inbetween. It is the same mesh with the same UV map, which gets updated and subdivided, so I can sculpt my heightmap into it. Or shorter: there is only one mesh (the low poly), which gets subdivided in Mudbox and becomes the high poly on level 8.

Baking these normals is working fine, it's just the texture that doesn't want to fit. Must have been something with my UV's, or something else broke. I got it working anyway (with a new plane) and here are the first results:

...the terrain didn't have Unique UVs assigned, btw. That was the problem. If you give the mesh a texture projection, make sure it's an unique one and scale it to size in your 3D studio's texture viewer.

Edited by: SinKing

mudbox has the option to rebuild the UV's at higher subdivision levels. Just do that.