Texture turns partially black in editor

[AggrorJorn]

I've seen this problem before on the forum but I can't find it back. I have a boiler which has a texture apllied to it. (See image). The 'rings' on the boiler turn partially black. If I rotate around the boiler, the black color folows.

Also a part of the box on front of the boiler has this problem. I tried exporting again with another texture, but the results are the same.

 

The texture I use is 512-512, DXT5 with mipmapping. I use the following .mat.

texture0="abstract::boiler large copper.dds"
texture1="abstract::boiler large copper_N.dds"
blend=0
depthmask=1
zsort=1
overlay=1
cullface=1
shader="abstract::mesh_diffuse_bumpmap.vert","abstract::mesh_diffuse_bumpmap_specular.frag"
shadowshader="abstract::mesh_shadow.vert"

[Masterxilo]

Hmm, maybe you have inverted faces.

[AggrorJorn]

I thought that that was the problem. But the black color turn with the camera. When it does that, the previous black parts are then fully textured.

[Niosop]

Try it with just a diffuse map, no normal map. If the problem goes away then it might be that the Y component of the normal map is inverted. If the problem doesn't happen when only using a diffuse then you can try adding:

 

normal.y *= -1.0;

 

right after:

 

normal = bumpcolor.xyz * 2.0 - 1.0;

 

in mesh.frag and see if that fixes it. If so, then you can leave it like that if all your normal maps are generated the same way, or use -Y in your normal mapping program and leave the shader the way it is.

[Marleys Ghost]

Sounds like the normal problems I had with models from dexsoft.

[AggrorJorn]

Try it with just a diffuse map, no normal map. If the problem goes away then it might be that the Y component of the normal map is inverted. If the problem doesn't happen when only using a diffuse then you can try adding:

normal.y *= -1.0;

right after:

normal = bumpcolor.xyz * 2.0 - 1.0;

in mesh.frag and see if that fixes it. If so, then you can leave it like that if all your normal maps are generated the same way, or use -Y in your normal mapping program and leave the shader the way it is.

Thanks for the help but unfortunatly removing the bump causes the same problems. Removing every texture and the mat shows a correct shape of the model. Problem is somewhere in the texture, matt or shader.

 

Sounds like the normal problems I had with models from dexsoft.

What did you do to solve this issue, besides remodeling and texturing.

 

I'm trying the same textures and mat files on different object, but that all seems to work. I think I'll start over with the model. Maybe there is just something wrong in my model.

[Niosop]

Check the faces that are appearing black. If your modeling program supports it, have it display the normals or turn off two sided rendering. Then you can see if those faces are facing the wrong way and flip the normals on those if needed.

 

Actually looking closer at that picture, it seems that it's definitely just that those faces just need to be flipped.

[Marleys Ghost]

What did you do to solve this issue, besides remodeling and texturing.

 

I did a quick fix in UU3D, selected all, made double sided and created a new group, selected all again and then flipped normals, then selected the original group and deleted the mesh .. probably the totally wrong way to do things but I ended up with a fixed model with the same poly count

 

or you can do what Nio said

[macklebee]

aggror, does your modeling program allow you to see which way the normals are facing? If so, i would try that... because looking at the picture above, I would say thats the issue... you can see the outline of the main model through the areas that have the texture problem... which kinda points to inverted normals from what I have seen...

[AggrorJorn]

I inverted the normals inwards and then back again like some kind of reset. But that didn't help. I also noticed that the camera is further away from the object, the texture is okay. when the camera comes closer, like within 10 meters then the black texture appears from out of nowhere.

[Niosop]

If you have an .obj version of it I'll be glad to take a look at it and see if I can fix it.

[Marleys Ghost]

What did you do to solve this issue, besides remodeling and texturing.

ooops wrong quotes

[AggrorJorn]

I see now that this only happens when I ad a point light to the scene. Without the point light, the textures are correct. Note that the object doesn't have baked textures.

[AggrorJorn]

I remade the model and used newly converted textures. So far the problem is not showing up. Lets hope it stays that way. Thanks for the help you offered me!

[Michael Betke]

Yes I have this problem if I forget to use the makedds.exe on my normalmaps sometime.

[tkunze]

I have the same issue. Strange enough for me it only appears on nVidia graphic cards and not on ATI cards.

 

It looks like it is related to the UV coordinates. Most time i got it solved with using the "Relax UV"

option in Ultimate Unwrap. The model looks ok in Unwrap 3d and in some other engines i tried. Only

with Leadwerks and nVidia card i get this black areas.

 

In my case (i mainly use Delgine 3d as Modeller) everything was Leadwerks campatible by switching from

the Collada to the .X Format.

[AggrorJorn]

I have the same issue. Strange enough for me it only appears on nVidia graphic cards and not on ATI cards.

 

It looks like it is related to the UV coordinates. Most time i got it solved with using the "Relax UV"

option in Ultimate Unwrap. The model looks ok in Unwrap 3d and in some other engines i tried. Only

with Leadwerks and nVidia card i get this black areas.

 

In my case (i mainly use Delgine 3d as Modeller) everything was Leadwerks campatible by switching from

the Collada to the .X Format.

can you post a screenshot? I had some troubles with black textures as well. I noticed that a bumpmap I was using didn't have a regular size like 512 x 512 or 256 x 256.

[tkunze]

this is one of the black areas in my model. It happens regardless from the texture size and with/and without the use of bumpmaps. But the same model with ATI cards looks ok.

 

If i use 2D Tools - Relax UV's most of this areas are corrected (but in same rare cases it still appears).

 

As said fortunatelly in my case switching to .X export in Delgine created UV coordinates which do not show

the problem.

 

But the really tricky thing is it only appears when i view the leadwerks model with nVidia cards. Everything looks ok in Unwrap 3d and i tried the model in 3d gamestudio, torque and the C4 engine and none of this engines shows this

behaviour. The model always looks correct.