FBX importer not importing more than two map channels?

[Michael_J]

So, I'm trying to import an FBX object with 3 unique UV map channels. It appears that the importer is not handling the 3rd map channel though. The results I'm getting in the editor would suggest this at least.

 

I imported the object back into MAX, into a new file, and the 3rd map channel is there; so I know that the MAX FBX exporter is storing the data correctly.

 

Josh, can you confirm that the 3rd map channel is infact being "ignored" by the importer. If so, I would consider this a bug--there are many reasons why you'd want the ability to have three and even four unique map channels. Otherwise, then the bug is with my shader.

 

In theory, this should work, yes?

 

Vertex shader:

 

in vec2 vertex_texcoords2;

out vec2 ex_texcoords2;

ex_texcoords2 = vertex_texcoords2;

 

Fragment shader:

 

in vec2 ex_texcoords2;

vec4 paint = texture(texture5,ex_texcoords2);

SV46_hull_TAILlogo.FBX

[shadmar]

Maybe the gmf (now mdl) format doesn't have support, I think the gmf SDK is downloadable somwhere in here so you can have a look.

[Einlander]

the gmf format is extremely flexible. It "can" support the extra uv maps, but Leadwerks doesn't use them. You can see an example of this by loading an fbx with vertex Colors. Open it and save it. Colors are gone. I learned that when I was baking AO maps to the vertexes.

[macklebee]

You can see an example of this by loading an fbx with vertex Colors. Open it and save it. Colors are gone. I learned that when I was baking AO maps to the vertexes.

 

http://www.leadwerks.com/werkspace/topic/12444-importing-fbx-as-black-mdl/#entry90101

 

hmmm - it looks like vertex colors are being stripped no matter what - even though its a user-clickable option in the model editor. This is a separate bug report.

[Josh]

Leadwerks supports two texcoord channels.

[Michael_J]

Well, that explains that. So.... is there any chance of supporting three? Artistically speaking, I would consider three UV map channels (or texcoord channels, if you prefer) the minimum once you start getting into more advanced art.

 

If not, then you might as well close this thread and I'll try to come up with some work-around...

[Josh]

What are you using this for? I have never heard of using three. We don't even use the second channel for anything, it's just there basically for historical purposes.

[Michael_J]

It's pretty important if you're doing multi-layered and/or effects art AND want to save texture space. An example:

 

TexCoord 1: tiled maps for the diffuse layer (higher texture detail without using large maps)

TexCoord 2: a baked AO map, spec mask, or normal map that requires a one-to-one mapping

TexCoord 3: UV animated effects, layered texture details, or other effects elements that require their own unique coordinates.

[Josh]

For animating texture coordinates, wouldn't it be easier and faster to pass a uniform to the shader for this?

[Michael_J]

what you're animating may very well need unique mapping regardless. But that was just an example. The point is, there are many artistic reasons to make use of 2 and even 3 unique sets of texcoords. I've been a professional 3D environment and FX artist since 1999--I'm not just making this stuff up

 

However, this is your engine. If you only want to support 2 UV map channels that's fine (regardless if I agree or not). Just tell me so I can come up with an alternative...

[Josh]

It would be easier not to go in and change it. Do you have a really good example of when this would be used?

[Michael_J]

Sure...

 

Tiled diffuse on TexCoord 1

baked lighting on texCoord 2

High detail stains, insignia, etc THAT ACCEPT THE BAKED LIGHTING (decals would not) with TexCoord 3

 

Baked lighting is STILL often a viable solution, especially for AO.

[Christian Clavet]

Hi, Since Leadwerks will never support lightmapping again. It would be really important (at least for me) for me that at least have support for 2UV. And would be really useful as Michael mention: BIG OBJECTS need TILING. If we want to bake the lighting out of Leadwerks on those big objects that have tiled texture, we absolutely need a second UV. (I've read somewhere that this could be bypassed by using a TRIPLANAR shader, but I don't know to implement it)

 

Have someone made a material that support this or we will have to create it?

-Texcoord 1 - diffuse

-Texcoord 2 - Lightmap

 

Michael, using a 3rd texcoord for details is interesting (especially for big objects!!), do you have any more information on how it's done? I always used decals for that.

 

By the way, I tested exporting a map yesterday from Leadwerks to 3D Studio Max and bring it back, it work perfectly! The scale is not affected at all and we can really use the mesh as reference in Max. I only baked everything in a diffuse map, so I've not tested how to import back with a diffuse tiled map, and a lightmap yet...