hedphelym wrote:When you split the mesh like that, does that not cause renders to take longer? or that light leaks into model?
(If I understand the splitting correctly, then you "detach" the faces based on smoothing angle \ texture), correct?
The render won't take longer because the intersection only uses the geometry information, it doesn't know which mesh a triangle belongs to.
As long as you can ensure that a vertex is exported with the exact same coordinates, you won't get more light leaks.
And you're correct regarding the splitting: if you have 2 faces sharing an edge and want each face to have its own set of normals, then you'll have to output the edge vertices twice to be able to assign different normals (or UV values, that's mostly the same issue).