View Full Version : Mapping a Nurbs Surface

05 May 2007, 09:53 PM
When I map a nurbs surface with a texture made to size things work great.

If I had a second object, @ a different size and I try and map it with the same shader... it will stretch or squeeze that shader into that shape.

I understand what it's doing but I was wondering if there is a way to alter how a texture is mapped on a surface and control it with attributes associated with the object.

Instead at this point I have to creat two different shaders with different offsetting's, tilings and repetitions within the 2D texture placement node.

I would rather have 1 Material Shader and use the objects to adjust how that shader gets mapped out on a per object basis.

Does that make sense?

I've attached an image to show the issues.

05 May 2007, 06:47 AM

what you are describing is the beauty (and downfall) of using NURBS surfaces. Only the surface parameters and CV placement determine where a mapped texture will be placed. This can be advantagous for hard surfaces or simple organic shapes since there is no real setup of UV's, but I'm afraid if you really want to control how your texture is mapped you need to use poly's and alter your UV's. You can also evenly spread out your Isoparms in your nurbs surface and that should help your texture stretching, but it will increase your geomerty complexity quite a bit.


05 May 2007, 05:26 AM
Things you might want to try:
1. Apply the map as a projection instead of normal mapping of the texture. A planar projection could seamlessly cover both those surfaces with one texture.
2. The tripleShadingSwitch node lets you have an unlimited number of different texture maps, with a different map on each surface, with one shader. That way you can still make shader-level adjustments to all the surfaces at once, but also adjust the mapping on each surface separately.


05 May 2007, 06:45 AM
tripleShadingSwitch node... that's sounds like what I'm trying to do. I'll look into that.

Thanks guys.

CGTalk Moderation
05 May 2007, 06:45 AM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.