These are tips about animating NURBS models and using textures with animated NURBS models.

• An easy way to animate a growing surface is to put a curve point with trimming on a curve, then animate the U position of the curve point, and then use this curve as the rail of a 1-rail sweep. As the trimmed rail grows, so does the sweep surface. (You must trim the curve before you create the sweep surface.)
• If you see gaps between surfaces in rendered images, increase the value of Merge for the renderer in the surface approximation settings.
• If a texture slides around on the surface during animation, this is because you are using the default Chord-Length parameterization of the texture surface. Select the surface, then on the Material Properties rollout change the parameterization to User Defined. Now the texture should stick to the surface better.
• Don't use the UVW Map modifier to apply a texture to an animated NURBS surface.
• If a surface seems to glitter or jump around as you move toward it in an animation, this is because View Dependent tessellation is on (on the Surface Approximation rollout) so the tessellation is constantly changing. Usually View Dependent creates no visible changes, but if it does, turn it off.
• If a surface seems to glitter or jump around while it changes during animation, this is because the tessellation is changing as the surface animates. Changing surface approximation (on the Surface Approximation rollout) to Regular fixes this in all cases. Parametric tessellation also solves this problem for every kind of surface except U lofts and UV lofts.
• If the View Dependent setting doesn’t seem to be doing much, change the tessellation (on the Surface Approximation rollout) from Curvature to Spatial. You will then get a much more drastic change in face count.
• To get a map to smoothly cover two or more surface without tiling, create another surface whose shape covers and roughly conforms to the original surfaces. Apply the texture to the larger surface. In the Material Properties rollout for the original surfaces, set Texture Surface to Projected, click Pick Source Surface, and pick the larger surface. Adjust the larger surface to fine-tune the map projection. Hide the larger surface before you render.
• To have different maps on a surface sub-object, use different mapping coordinates and multiple map channels. On the Material Properties rollout, change the Map Channel value and then turn on Generate Mapping Coordinates. (Each map channel requires its own set of mapping coordinates.)

  NURBS surface sub-objects let you set the map channel directly, and don't require you to apply UVW Map modifiers as other objects do.

• If a map doesn't align to a surface sub-object the way you want it to, on the Material Properties rollout choose User Defined as the Texture Surface, and then use Edit Texture Points or the Edit Texture Surface dialog to move the points of the texture surface.
• To adjust how the map aligns to the edges of a surface sub-object, use the Texture Corner settings on the Material Properties rollout.