Surfaces, like curves, have child classes, but surfaces are far more complex and have a far greater number of child classes, including trim classes. There are also surface methods which allow you to project a curve onto the surface, create a curve-on-surface, and other methods which allow you to trim the surface using the curves on the surface.

Above is a surface node, its surface object and associated objects for control vertices (CVs) and curve-on-surface’s. To create a surface/surface node pair, first instantiate and create an AlSurface, then instantiate and create a surface node. The surface CVs are created automatically. To create a curve-on-surface, instantiate and set the data of an AlCurveOnSurface object, then add it to an AlSurface. While you are able to add rows of CVs you are not able to delete CVs. Make sure you create a surface node for each surface that you create; a surface without a surface node is not added to the universe, and if the pointer is lost, the surface would become wasted memory.