Materials on a rotated object are not showing correctly with Advanced Lighting Model

[Lenaranel]

I'm having a problem with using materials on objects that are rotated. 

I first noticed the problem on pieces of mesh wall, where I had a 3m x 2m corner piece and needed to rotate it 180 degrees to fit it into the build. I noticed that the texture on that rotated piece did not match the other pieces on the wall when Advanced Lighting was turned on.

Rotating the texture is not the problem. As long as the object remains in its initial/default orientation, I can rotate just the texture/materials 180 degrees and they look fine (just upside down). I've tried it on many differnt objects (mesh and prims) and with other textures/materials and still got the same results.

Any ideas on why it's doing this and if it's possible to fix this within SL?

Here's a photo to show what's happening. The center prim is in its default orientation and has the textures/materials applied normally. The cube on the left is in default orientation but the textures/materials are rotated 180 degrees (still looks okay, just upside down). The cube on the right has been rotated 180 degrees on the X axis. The textures/materials were then rotated 180 degress so that they would be "upright" and match the center cube. And no matter if the textures/materials are at 0 degrees or 180 degrees, it looks all sorts of wrong. :-\

http://tinypic.com/m/j5ift1/3

Thanks!

Lenara

[arton Rotaru]

Yeah, rotating a normal does not work. The shader is calucating the green colors in the map as Up and the red colors as Right against the UVs. So if you rotate the normal map 180° it's the same as you would invert the red and green channel of the normal map.

To fix this I would rotate the mesh in my modeling program so that it fits correctly, zero out rotations and upload it again.

[Lenaranel]

Unfortunately these aren't my mesh pieces, they are Full Perm pieces I purchased. And it also occurs on the SL prims. But thanks for the explanation! I guess this is incentive to find time to finally learn Blender! :-)

[arton Rotaru]

Another way to "fix" it, If you have access to the normal map outside of Second Life, would be to invert the red and green channel of the normal map in Photoshop. But that would be kind of inefficient, to load yet another map.

Learning Blender won't be the worst decision, in the long run. :matte-motes-smile:

[Lenaranel]

Ha! Inverting the channels fixed it. Thank you so much!