Materials will not assign correctly

[Pamela Galli]

This is a new one for me, and it may or may not be mesh related.  I applied a blank texture to the inside of my lamp shades but every time I mod the lamp in any way -- apply another texture to another material, scale the mesh, whatever -- it reverts to the wrong texture (the texture applied to a metal part of the lamp).  I have tested and the bugged faces have the correct material assigned. Looks like this:

 

[Pamela Galli]

I found a clue. Some of the metal parts have the same material as the inner shade material -- inworld.  In Blender all the metal faces have the same material.

 

When I upload and apply the metal texture to the metal faces, a few stay white. When I apply the metal texture to those white parts (I made them blue in the pic), the inner lampshade takes the metal texture too.

In Blender, everything has the correct material applied, so I am befuddled.

 

 

ETA:  Normals are fine, there is no duplicate geometry (that I can find).

[Pamela Galli]

I did not find a fix but a work-around.  I exported and then imported as an .obj, then uploaded to SL.  Now, the metal still behaves like it has two materials assigned instead of one -- I had to apply the texture to two parts of the metal face, since applying it did not cover the whole face as it should -- but at least it no longer has the interior of the lampshade assigned the same material. So at least it looks like it should.

 

 

[Pamela Galli]

Oh the reason that worked -- the .obj was separated into separate meshes by material, although it was exported from one mesh.  The bugged face with two materials was not separated into two meshes, tho. 

[LepreKhaun]

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Pamela Galli wrote:

Oh the reason that worked -- the .obj was separated into separate meshes by material, although it was exported from one mesh.  The bugged face with two materials was not separated into two meshes, tho. 

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That was a good clue to what is going wrong. It's not that the "bugged face" has two materials, it's that your material there is either being mapped to two differing UV images or you have overlapping UV islands from different materials within that area. This is completely allowable and is "a good thing" within Blender (allowing, for instance, smooth blending from facial features into the hairline) but can lead to problems in SL, where we deal with material "faces" and expect unique UV assignment of each..

 

To rectify/avoid that you need to unwrap everything again, making and saving a NEW UV texture for each individual material. Every material should have its own UV mapping with no other materials involved in it. See http://wiki.blender.org/index.php/Doc:2.6/Manual/Textures/Mapping/UV/Layout_Management for details on how to do this. I'll also IM you with some personal specifics regarding this.

[Pamela Galli]

Thank you I will keep this in mind if it happens again. Since it looks fine inworld now, I am not going to do anything else to this particular mesh.