Specular highlight not lining up between modular meshes?

Chandler

Hey guys, I was wondering if anyone might be able to help with a UDK problem that's been puzzling me for a few hours. I've imported a modular mesh, given it tiling diffuse, normal, and specular maps, and cloned it over a bunch of times. However, the specular highlight along the top isn't lining up between meshes for some reason.



I don't think it's an issue with lightmass, as it occurs whether or not lighting has been baked. Here's a list of things I've tried already-

- Checked normal and specular maps to ensure they are correct (The problem still occurs when the normal map is removed from the material and the spec map is one solid color)

- Increased lightmap resolution

- Tried different lighting setups and changed from point light to dominant dynamic light (No change)

- Made sure I had an alternate UV channel for lightmaps and checked UV shells to make sure they're not overlapping, not intersecting any pixels, have enough padding, etc.

- Checked base mesh to make sure vertices are lined up properly (It's a cylinder, so the highlight should be straight horizontal)

So, has anybody encountered anything like this before, or have any ideas? I'm pulling my hair out over here.

Fingus

It's because they are separate meshes so the normals don't line up. It's like having a hard edge/smoothing group applied to it. When doing modular meshes like this you need to cover up the seam with either a split in the texture/model that makes sense or simply cover it up with other modular assets.

Chandler

Oh, okay. I haven't really worked much with modular stuff before, so I'm not familiar with a lot of the practices when modeling this way. I'll just add a connector piece or something between the meshes. Though I still can't say I completely understand... I'd have thought the normals would be facing the same direction for the whole length of the mesh, since that section is just one straight cylinder and there's no normal map detail on those UVs.

In any case, thanks for the help!

Angry Beaver

There's probably ways to reduce how apparent it is by getting finicky with your modeling and adding extra edge loops but, but it'll only reduce it not solve it. Your best bet is really to hide the seam, so instead of splitting in the middle of a tile like that split where the flat edge meets the rounded edge and come up with some connector for the top of your roof.