Surface Analysis: Slope vs Draft

If you were examining a drafted surface and checked against the same 'hinge' surface, they probably would give the same result. Slope is just capable of telling you a lot more than the draft check function which only says is this surface more or less than this angle. : : I'm trying to smarten up my surface of last week (the tangency problem one).

Slope is good for seeing discontinuity. So is Gaussian curvature (similar to slope, but not measured against plane), porcupine is excellent and so are highlight curves (zebra stripes) for seeing discontinuity between surface patches.

David Janes

I worked out that Slope also doesn't distinguish between whether the surface is sloping backwards or forwards. IOW 2 surfs with a 1 deg draft will be colored the same even if one is one the other half of the mold.

I find it very hard to make a surface that doesn't go crazy in porcupine.

What I sometimes do is pattern a bunch of intersection curves which gives me a relief map of the surface. Also it's always there. If I save a surface analysis it's hard to see the curves underneath to modify them.