About this project
A test bench for the mesh post-processing stack. A rounded body and a small cylinder placed well away from it are unioned into one result, and that union node carries three post-processing steps in order: repair, remesh, decimate. Each step has its own switch, so the stack can be applied one layer at a time to the same mesh. This is a lab scene, not a part.
The source geometry
The body is a rounded box with a 4 mm corner radius at 64 segments, which is where its triangle count comes from. Its width, depth and height are fixed rather than exposed as controls. The cylinder sits at a distance from the body, so after the union it is a disconnected shell. That is the island the repair step is there to catch.
Repair
Repair removes degenerate triangles and disconnected islands. Island triangle limit, 50 to 300 in steps of 10, is the number that matters: any disconnected component below that triangle count is discarded. Move it and the cylinder disappears and returns. Hole filling, winding repair and vertex welding are present but switched off, so what you see is island removal alone.
Remesh
Remesh rebuilds the triangulation towards a target edge length, 0.25 to 2 mm, with edge collapse, split, flip and vertex projection active. Target edge length is the dominant control: small values give an even, dense mesh, large values a coarse one. Passes, 1 to 6, decide how close the result gets to that target.
Decimate
Decimate reduces the triangle count after remeshing. Fraction retained runs 0.25 to 1 and maximum allowed error 0 to 0.05, and the two interact: the error cap can stop the reduction before the requested fraction is reached. Boundary protection is on at a high weight with a 60 degree crease angle, weighting boundaries and creases against collapse.