Boss Failure

G’day McNeel,

The attached file has a closed polysurface and two rounded corner squares that are duplicates. The red one fails to boss (with 10 degree taper) to the polysurface but the green one succeeds. If you mirror the polysrf and red curve upside down (about any horizontal plane), then it works as expected (see model).

This is just a demo. I managed to resolve my real model with the mirroring trick.

Boss Failure.3dm (235.7 KB)


Dir command on the curves should do the trick.
Boss extrudes curves normal to the curve plane.

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Hi Nick - thanks, I see that.
RH-65555 Boss - extrusion direction misses


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No, it’s not a problem. What was interesting was that a planar curves direction had any bearing on the boss command. I hadn’t even considered it would, instead testing if the bossing direction (positive or negative Z) or a change from positive to negative Z height between the curve and the surface were to blame.
The fact that this has not previously been brought up also shows the fix is well known or Boss isn’t used regularly, both of which are interesting too.

I’ve been using Rhino for over a decade and don’t recall having heard of Boss.