negative volume

It looks like scaling geometry with a negative factor generates objects with a negative volume.

Attachments:

box neg volume.gh, 6 KB

Replies to This Discussion

Permalink Reply by David Rutten on February 3, 2015 at 11:47am

˙ʇno ǝpᴉsuᴉ uoᴉʇɔǝɹᴉp lɐɯɹou ǝɥʇ sdᴉlɟ ʇɐɥʇ ǝsnɐɔǝq ǝq ʇsnW ¡ƃnq ɐ s,ʇI

Permalink Reply by Ethan Gross on February 3, 2015 at 12:45pm

Actually, I've found that negative volume is a useful way of seeing whether a brep needs to flipped.

Permalink Reply by David Rutten on February 3, 2015 at 1:25pm

Closed breps should always be oriented properly. Rhino starts doing all sorts of weird things if they aren't.

Permalink Reply by Ethan Gross on February 3, 2015 at 1:41pm

I was extruding a few dozen curves to a point in order to do a boolean split, so they were not closed breps themselves. When I baked them, some had outward normals and some inwards, with no seeming rhyme or reason, so I tried using the volume component in Gh to see what resulted. I know that it is meant for closed breps but in my case, it was reliably able to distinguish which needed to be flipped or not.

Permalink Reply by Matthew Johnson on September 23, 2019 at 8:03am