Scale of materials

[j2cervin]

It is probably painfully obvious that I am new to this program. I have been going through all the tutorials and gaining basic knowledge about how to use Vray. However, I do not understand the scale of a material when you create one from a bitmap.

What I am trying to do is create carpet for a ground plane. I have a good texture map in 2 sizes (3000 X 2000, 800 X 500). I added a map to the diffuse and used the same image as a bump for the texture. However, no matter what I do I end up with large splotches. Is the scale of the material based on the scale of the object?

[j2cervin]

Re: Scale of materials

I suppose that is what the UVW Transform is for? There is so much to learn about this program that I dont know where to start!

[dalomar_cg]

Re: Scale of materials

I have to answer your question with another question...which part of a material? There are a number of things that will reference scale and a number of ones that it doesn't matter.

As far as mapping goes, by default a texture will reference the surface UVs. Even though this isn't a specific scale, it does reference the "size" of those UVs. And of course, when you actually create a mapping widget it will reference the scale of the scene. When talking about bump maps this has a bit more gray area. Since bump maps don't actually create anything, its just a simulation, but even though its not "real" the multiplier will reference the scene's scale and indirectly the scale of the object. Displacement on the other had is very tied in to the scene's scale since that will be an accurate representation of the surface (ie. my scene is in inches and I want a displacement height of 3.5 inches I would have to set the multiplier to 3.5)

There are other material properties that will directly reference an objects. Most importantly is fog. The same fog material will have a different appearance with two objects (one thick and one thin), even have a different appearance of a single object of different thicknesses. The rule of thumb is that if you have an object that is one scene unit thick and you're fog multiplier is 1, then the result will be whatever color you set.