Connecting Intersecting Tubular Meshes for Water Flow

[doknicilija98]

Hello,

I have two intersecting meshes that are tubular and hollow inside, as shown in the picture below. My goal is to connect these tubes in a way that allows water to flow seamlessly through them.

I have tried using the Boolean operations like mm.BooleanOperation.InsideA and mm.BooleanOperation.Intersectionbut they return empty meshes and undesired results.

Could you please explain how I should proceed with connecting these tubular meshes?

[Grantim]

Hello!

I think in this case you need mm.BooleanOperation.Union operation

[Grantim]

Could you please provide meshes? It will be very helpful to diagnose the problem

[doknicilija98]

Does this error message help in any way?

Bad contour on 2 mesh A faces, probably mesh B has self-intersections on contours lying on these faces.

I got it by running the following code

result = mm.boolean(meshA, meshB, mm.BooleanOperation.Union)
result_mesh = result.mesh
if not result.valid():
    print(result.errorString)

[Grantim]

It means that boolean operation cannot be performed because of self-intersections on meshB, you can try heal it with https://github.com/MeshInspector/MeshLib/blob/master/python_scripts/healer.py this script or with something like this:
https://github.com/MeshInspector/MeshLib/blob/master/test_python/test_fixSelfIntersections.py

But really each mesh with self-intersections may require different approach

[doknicilija98]

meshB has many independent, nonoverlapping parts. Is there a way to split those and then remove parts that have self-intersection?

[Grantim]

Something like this should work

selfies = mm.localFindSelfIntersections(mesh)

components = mm.getAllComponents(mesh)

removeCompomemnts = mm.FaceBitSet()
for c in components:
    if (c & selfies).count() > 0:
        removeCompomemnts |= c

mesh.deleteFaces(removeCompomemnts)

# optionaly
mesh.pack()

assert mm.localFindSelfIntersections(mesh).count() == 0