04:05 <awygle> there's a red... region? being rendered on my model, is there a way i can tell which group or constraint is causing this? i'm assuming it's either overconstrained or one of those angry NURBS issues...

04:20 <swivel> awygle: in the popup window with all the groups listed, it usually says "SOLVE FAILED! redundant constraints" when it's overconstrained

04:21 <swivel> with a list of relevant constraints...

04:22 <awygle> hm not seeing that, must be NURBS then i guess

04:23 <swivel> this is one area solvespace could use some wokr

04:23 <swivel> *work

04:23 <awygle> oh, i found the chord tolerance and made it tighter and now it's happy. odd. but helpful

04:27 <awygle> can i move a workplane?

04:28 <awygle> i accidentally made this one floating 2mm above the plane it's supposed to coincide with, and it's in the middle of the stack so if i delete it it might mess up a bunch of other stuff

04:32 <awygle> i guess moving it might mess things up too. darn. oh well, i'll just delete it i suppose

05:47 <awygle> hm okay now i have a more serious NURBS problem, is there any way to figure out why it can't perform the Boolean operation?

05:48 <awygle> googling basically tells me it has something to do with surfaces being too exactly coincident, is that right?

06:02 <awygle> (i have now resolved the situation by displacing some workplanes by a millimeter, but would still like an answer to the general question if possible)

08:02 <whitequark> awygle: red regions being rendered (as opposed to there being errors in the property browser) are always caused by solid operation failures

08:03 <whitequark> the answer to the general question is... well... I don't know either. I'm not a NURBS person.

08:03 <whitequark> they fail seemingly at random all the time and the only two options available are: use OpenCASCADE, or write our own backend that works as well as OpenCASCADE.

08:04 <whitequark> the former is not really viable for a number of reasons, and the latter requires a lot of capital.

08:04 <whitequark> increasing chord tolerance improves the result where the NURBS operations are using the piecewise linear representation for something (I think it's computing some sort of intersection)

08:07 <awygle> I see. Well, "offset work planes by 1mm until red goes away" has been sufficient so far, guess I'll keep doing that.

08:07 <awygle> What's up with this "force to triangle mesh" option? The docs seem to be saying that even though that makes things work, I probably don't want it?

08:21 <whitequark> you probably don't want it because you probably are using a tool using exact representations of surfaces for a reason

08:22 <whitequark> it depends on why you're modeling. if you want to 3d print stuff, or to display it on a webpage, it's fine.

08:22 <whitequark> if you want to send it to a machine shop that wants STEP with NURBS solids, nope.

08:25 <awygle> I am planning to 3D print prototypes for injection molded parts, so probably I need the NURBS.

08:34 <whitequark> yep.

08:41 <awygle> Got it. Thanks again!