Help How to build a goal net mesh to use with Obi?

[gabrimo]

Hi!

Here each edge is shared by more than 2 faces, so this is by definition a non-manifold mesh and can't be simulated (as it can't exist in the real world).

There's no need to duplicate all faces and flip their normals. It's simpler and cheaper to just disable backface culling in your material, or use two materials (one for side A, one for side B, this is what the sample scenes in Obi do) or use a two-pass shader.

Ok but how shoud I compose the model? Maybe with 4 separated planes (one each side, one top and one back)?

This model is all connected, like a rectangle with 2 faces deleted. I read the definition of manifold and assumed that this model wouldn't work, but my doubt is how should I build the goal net to be functional with Obi.

If I build it with 4 planes, I imagine there would be issues regarding collisions in the edges for example..