Problem revolving: invalid brep

Grasshopper
1

Any clues what’s going wrong here? I’m getting “invalid brep” from RevSrf, while trying to create a bowl/pot shape by:

  • making a (poly?)curve to define the outside profile, horizontal from the origin out for the bottom, curving up for the side
  • offsetting that outside profile curve to get an inside profile curve
  • flipping the inside curve, so its start is up at the rim where the outside profile ended and its end is back on the z-axis
  • connecting the two, making one (poly?)curve of the two, with a little segment across the offset at the rim
  • revolving that result around the z-axis

Some similar attempts work (produce valid surfaces), but I haven’t figured out a pattern to which do and which don’t yet.

pot.gh (6.8 KB)

2

pot
pot836×258 18.7 KB

This produces a closed brep

pot2
pot2929×290 25.9 KB

And so does this. It was probably the flip going into the connect curves which was the problem

3

pot_2020Dec28a
pot_2020Dec28a1255×494 85.8 KB

pot_2020Dec28a.gh (6.3 KB)

4

Thank you.

Any hints to help me understand what’s wrong with using the flip?

5

Thanks! That’s tidy, and teaches me something.

6

The mystery to me is why a data tree goes into Brep Edges with two branches but comes out with only one branch?

pot_2020Dec28a2
pot_2020Dec28a2710×281 26.4 KB

If the input to RevSrf is flattened, the data tree going into Brep Edges has one branch with two items and comes out with two branches, as expected. That requires the input to Loft to be flattened, again as expected.

pot_2020Dec28a3
pot_2020Dec28a3710×293 27.3 KB

“Ours is not to reason why…” but to just deal with it. :sunglasses: