Yet another shape.

 From:  Michael Gibson
694.4 In reply to 694.1 
These are definitely drawing out some really good information!

The key part at the start here is again to break things down into components.

This is a good example that sometimes the components can be pretty subtle - in this case I'd say that there is a kind of underlying surface sheet giving the main form. That's one component. One important thing about NURBS shape design is sometimes you want to focus on just a larger surface sheet and then give it the exact final shape by trimming it down. So sometimes you don't want to focus so much on the outline as the way to start the surface, kind of see the outline as being applied to a more simple surface. Like in this case you would probably go crazy trying to figure out how to sweep or loft that kind of 3-spoked shape directly.

I think that is generally a common way to go down a bad path, I mean trying too hard to construct a surface directly along a boundary where it isn't a natural fit.

So in this case there will be maybe a slightly squished sphere as the base shape (or you could make something more custom by sweeping or lofting), that will get trimmed by a curve projected on to the front of it. Each of the dimples is another component - those will be formed by cutting into the main surface with a small concave shape and then blending them.

Then the outside rim is a sweep along the outer trim curve.

So you can kind of get the feel for this type of "construction" or "drawing" based modeling - I try to construct each piece more by drawing and applying curves and assembling pieces together, not so much by squishing points around. That's the big fundamental difference in technique from a polygon/subd modeler.

But it's getting pretty late over here, I'll do the actual steps tomorrow.

- Michael