Problem with bump map

[sanpol]

Hi everybody,
I have a big problem with bump map because I assign a bitmap to the bump slot in a vray material and I'm unable to resize it. I applied mapping with various dimensions but I don't understand how bump work right. Sometimes the texture change a little when I try to set, but I don't know why.
Someone can help me, please? A short tutorial will be appreciate.
Thanks

[sanpol]

Problem with bump map

I have discovered that with a standard polysurface like a cube or a sphere the bump work fine, but with my polysurface I have no possibility to change mapping size. I have exploded polysurface too but no change I have seen.

[joe_b]

Problem with bump map

What UVW are you using for your bump map? Are you using explicit channel 1? If so - does your polysurf have mapping channels on it? Some imported geometry doesn't have surface uvs - but Spheres and Boxes created in Rhino do...so maybe thats the difference?

Select your poly-surf and in the object properties go to "Mapping". Then hit "Advanced view". Finally add a new mapping channel. This should apply uvs to your polysurf

[sanpol]

Problem with bump map

Thanks Joeb,
I tried using Box UVW map and the others too. The surfaces are created with rhino. My suspect is that there is a settings in the rendering option that cause me the problem.

p.s. I can upload some example images but I don't know how to do it.

[dalomar_cg]

Problem with bump map

I use www.imageshack.us and it generates the necessary code for you as well so its very easy