I need to create an object mesh with two sets of UV map coordinates. On the first uv map layer I want to have a base material that I can tile as much as I wish and the second uv map would cover all of the object without repetition. Imagine a wall where a plaster texture repeats itself all over the wall, but there is also a second coat of grime and dirt texture that extends the whole wall and doesn’t tile. I followed the answer on this thread (texturing - Map multiple textures to a face individually - Blender Stack Exchange) to assign multiple textures layers to the same mesh.
I know this will increase draw calls but that is not important for what i’m doing.
The problem is when I export to fbx, or even load the blend file in unity the mesh only has one material. How can I export the mesh so that Unity knows that the mesh has two materials and two sets of UV coordinates?
Has anyone managed this?
Unity can only draw one material per Triangel.
But you can use a shader that will mix two Textrest that projected by two different uvs.
You can use the standard shader, use the “coat of grime and dirt texture” in the primary map and use the small tiled "plaster texture " in the secondary map with a higher tiling.
(you could switch those around if you like)
A lightmap is exactly a new texture drawn on the same triangles taking uvs coordinates from a different uv channel with a specific blend mode. Does it use a shader to blend the lighmap and the main materials?
The standard shader is no good for what I need. I really need two materials.
Thank you for the reply.
The standard shader has some internal code that sample the lightmap and is blending it inside the one shader for the light calcaulations.
There is not 2 materials on one mesh.