Extra edges after complex subtraction about three-bvh-csg HOT 8 CLOSED

Can you please produce a simpler example that just includes the two geometries and the clipping operation and the wireframe?

Sure. here's a stripped down version.

from three-bvh-csg.

Looks like the eges issue can't be easily reproduced at the moment - we can track it down when it arrises another time:

from three-bvh-csg.

Interesting - I'm also seeing that "intersectionEdges" is reporting some odd extraneous edges:

Can you please produce a simpler example that just includes the two geometries and the clipping operation and the wireframe?

isWaterTight reports true for this mesh,

Also note that is water tight is not documented and not currently fully functional.

from three-bvh-csg.

I fixed #183 in v0.0.15 which seemed to be related but it does not seem to have fixed this issue. Are you seeing this same kind of issue with any simpler models? Ideally generated models from the three.js primitives?

from three-bvh-csg.

I've not yet seen it happen from a single subtraction between two threejs primitives, but I have seen it happen after multiple consecutive subtractions. I'll see if I can produce a simpler example on the latest update this week. Thank you for investigating!

from three-bvh-csg.

It looks this this is happening as part of the "full triangle" accumulation step - ie the step where unclipped triangles are appended to the result.

These edges look like they intersect the the clip volume but the intersection detection skips triangles marked as "degenerate". It seems they're inadvertently being added to the result geometry elsewhere, instead.

They're gone if we filter triangles with area === 0 when building the result geometry:

These degenerate triangles are in the original model, as well - 563 of them. I guess these will have to be filtered out during the clip process. I'll just have to think abut the right place to do it.

from three-bvh-csg.

#193 should fix it:

from three-bvh-csg.

I still want to check out the "intersection edges" issue listed above, though.

from three-bvh-csg.