I know - more or less - how to draw closed 2D-shape outline from Bezier-like strokes with jit.gl.sketch, but I don’t know how to fill the shape.
Is there a way to build 2D shapes with jit.gl.nurbs from outline coordinates ?
I think this is a non-trivial problem to solve in Max, because holes can be caused by the sequence order of the points. But I can't tell offhand if that is the cause with your particular abstraction due to the shape complexity.
If that is the cause, the easiest solution is to start with a grid and distort it, rather than drawing the nurbs object directly. that way you can apply clipping to the amount each point is allowed to move so that the points do not move outside the grid pattern.
Well it is not too difficult to set restraints on distorting a grid. If you clip it so the grid cannot fold across the center line, it should work. Generally it is better to use the control matrix to modify an existing shape, rather than to input the shape directly.