sinknurl - Cut a sinusoidal knurl pattern along the length a cylindrical object
Displacement "sinknurl" "maporigin" p "xaxis" p "yaxis" p "zaxis" p "freq" n "depth" n "zmin" n "zmax" n "dampzone" n
point maporigin=[0 0 0] point xaxis=[1 0 0] yaxis=[0 1 0] zaxis=[0 0 1] float freq=100, depth=0.005 float zmin=-1e20 zmax=1e20 dampzone=0
This shader cuts sinusoidal knurl grooves along the length of a cylindrical object. The parameters maporigin, xaxis, yaxis, and zaxis are used to do a cylindrical projection as described in maps(3sh).
The freq parameter gives the number of grooves to cut around the circumference of the object. By default this number is quite high, but low numbers produce a shape like a classic Greek column. The depth parameter controls the depth of the grooves.
By default, the knurl will be rendered along the entire length (along the z axis in shader space) of the cylinder. However, you can set minimum and maximum bounding z values with the zmin and zmax parameters. The surface will not have a knurl pattern cut outside these boundaries. In addition, you can make the knurl smoothly fade out instead of abruptly stopping at these boundaries by setting the dampzone parameter. This parameter controls the width of the zone in which the depth of the grooves goes to zero. This zone is inside the zmin and zmax boundaries.
Remember to set the displacement bounds attribute when using this shader.
This shader can have problems with aliasing.
Pixar Animation Studios