Seams along UV edges in UT3 when normal maps are applied
polycounter lvl 10
This has bugged me for over a year now, figured i'd finally make a post.
When i normal map an object, UV seams instantly pop into view. No seams are visible otherwise. Anyone know of a fix? First i nuked the red and green channels along the left and bottom edges respectively, still had a seam. Then i just threw a pure neutral blue over the whole thing and i still got seams. Here's a shot showing some hay i've been working on recently. I divided the top into 4 sections and rotated them to take up the same UV space:
Edit:
Also here's the lighting bake, showing minimal seams along the top, it's not vertex lighting, rather a 512 light map.
Any information is appreciated!
When i normal map an object, UV seams instantly pop into view. No seams are visible otherwise. Anyone know of a fix? First i nuked the red and green channels along the left and bottom edges respectively, still had a seam. Then i just threw a pure neutral blue over the whole thing and i still got seams. Here's a shot showing some hay i've been working on recently. I divided the top into 4 sections and rotated them to take up the same UV space:
Edit:
Also here's the lighting bake, showing minimal seams along the top, it's not vertex lighting, rather a 512 light map.
Any information is appreciated!
Replies
2. are the planes on the same smoothing group?
3. did you nudge the islands in the lightmap UV a few pixels away from each other where they are split? (again the thing i posted a link to in your UC thread)
4. why is there a ngon on top?
2. the entire object is on the same smoothing group
3. Aye they are nudged
4. Fixed the Ngon, still lighting seams.
Shouldn't have anything to do with light bakes, this seam shows up unbaked, and only with the normal map turned on. As best I can tell, UT3 somehow uses UV seams to determine smoothing groups for dynamic lighting, which seems really odd to me.
Turns out it is tied to UV seams, luckily only the seams in UV channel 1 (or 0 in UT3) will create these lighting seams.
So basically i made a junk UV map for channel 1 and just did a quick planar map with no seams in the UV map. Didn't spend any time making this UV layout look good. Then just moved the UV's I needed up one, changed the Map channels in the Mat Editor.
Here's the final result with normals, light bake, and most importantly, no seams!
Edit: at some point i'll fix the texel density on the sides once i get a decent texture going that doesn't repeat too much
http://book.hourences.com/tutorialsue3lightmap.htm
http://udn.epicgames.com/Three/LightMapUnwrapping.html