The Scale parameter allows the geometry to be scaled while being revolved or extruded. All scaling is done with respect to the centroid of the geometry.
Some examples of scaling:
The examples above all use Linear Interpolation for the scaling. Some examples that involve other Interpolations while extruding:
If zero is entered for the Scale parameter, then the geometry will degenerate to a point:
NOTE: Some models that were created with Spirix can be found at https://3dwarehouse.sketchup.com/user.html?id=1824658900641239202016828