In this example we will apply texture to the outside of a 6-sided tube. There are several ways of doing this and I will show two very differant possible solutions.
First we stretch the texture all the way around. Vertex 1 - 6 is the lower part and vertex #7 is vertex #1 with different UV values since vertex #1 is the starting point and can't be reused as ending point in this case. This pattern is repeated with vertex 8 - 14.
Since we wrap the texture once and the length of each side is approximately the same (not identical but close enough) we just divide 1 by 6 and get a increment of about .166. Note that I round off the numbers since we sometimes can forego total precision.
If you want a less stretched look in this example you can multiply the U values but I would recommend that the start and stop values here ended at integer values (or at the same fraction) for maximum seemless effect.
ModelBegin surface .5 .3 0 ClumpBegin Vertex -.03 0 .05 UV 0 2 #1 Vertex .03 0 .05 UV .167 2 #2 Vertex .06 0 0 UV .333 2 #3 Vertex .03 0 -.05 UV .5 2 #4 Vertex -.03 0 -.05 UV .667 2 #5 Vertex -.06 0 0 UV .833 2 #6 Vertex -.03 0 .05 UV 1 2 #7 Vertex -.03 .2 .05 UV 0 0 #8 Vertex .03 .2 .05 UV .167 0 #9 Vertex .06 .2 0 UV .333 0 #10 Vertex .03 .2 -.05 UV .5 0 #11 Vertex -.03 .2 -.05 UV .667 0 #12 Vertex -.06 .2 0 UV .833 0 #13 Vertex -.03 .2 .05 UV 1 0 #14 color 1 1 0 Texturemode lit foreshorten Texture smile Quad 1 2 9 8 Quad 2 3 10 9 Quad 3 4 11 10 Quad 4 5 12 11 Quad 5 6 13 12 Quad 6 7 14 13 ClumpEnd ModelEnd
A picture will only show part of this object:
The lower part is illustrated here:
In the second example we will have a differant approach. For simplicity I will tile the texture once on every polygon in the U direction. What is done here is that at every second polygon the texture is mirrored. This can be done if the texture is suitable for it. A wood texture (with its non-parallell lines) will most probably not look good here.
ModelBegin surface .5 .3 0 ClumpBegin Vertex -.03 0 .05 UV 0 2 #1 Vertex .03 0 .05 UV 1 2 #2 Vertex .06 0 0 UV 0 2 #3 Vertex .03 0 -.05 UV 1 2 #4 Vertex -.03 0 -.05 UV 0 2 #5 Vertex -.06 0 0 UV 1 2 #6 Vertex -.03 .2 .05 UV 0 0 #7 Vertex .03 .2 .05 UV 1 0 #8 Vertex .06 .2 0 UV 0 0 #9 Vertex .03 .2 -.05 UV 1 0 #10 Vertex -.03 .2 -.05 UV 0 0 #11 Vertex -.06 .2 0 UV 1 0 #12 color 1 1 0 Texturemode lit foreshorten Texture smile Quad 1 2 8 7 Quad 2 3 9 8 Quad 3 4 10 9 Quad 4 5 11 10 Quad 5 6 12 11 Quad 6 1 7 12 ClumpEnd ModelEnd
Again a illustration to explain how this is done. Note that in this case vertex #1 can be reused for the last polygon because we have a even number of sides.
In the beginning of this example I called this a tube but it hardly looks very round. That can be helped with the Lightsampling Vertex command. The default setting is Lightsampling Facet meaning that each polygon is treated as a flat surface. With Lightsampling Vertex the renderer will make the surfaces look smoothed and is a recommended way of making smooth rounded surfaces with a minimum of vertices and polygons.
ModelBegin surface .5 .3 0 ClumpBegin Vertex -.03 0 .05 UV 0 2 #1 Vertex .03 0 .05 UV 1 2 #2 Vertex .06 0 0 UV 0 2 #3 Vertex .03 0 -.05 UV 1 2 #4 Vertex -.03 0 -.05 UV 0 2 #5 Vertex -.06 0 0 UV 1 2 #6 Vertex -.03 .2 .05 UV 0 0 #7 Vertex .03 .2 .05 UV 1 0 #8 Vertex .06 .2 0 UV 0 0 #9 Vertex .03 .2 -.05 UV 1 0 #10 Vertex -.03 .2 -.05 UV 0 0 #11 Vertex -.06 .2 0 UV 1 0 #12 color 1 1 0 Texturemode lit foreshorten Lightsampling Vertex Texture smile Quad 1 2 8 7 Quad 2 3 9 8 Quad 3 4 10 9 Quad 4 5 11 10 Quad 5 6 12 11 Quad 6 1 7 12 ClumpEnd ModelEnd
The result look like this:
