I need to transform the vertex and index data of a mesh from a GLTF file into that of an OBJ file for the purposes of applying V-HACD.
I notice they aren't too dissimilar by comparing the mesh data of a cube in both formats:
| OBJ Verts | GLTF Verts | OBJ Index | GLTF Index |
|---|---|---|---|
| -100 | -1 | 1 | 3 |
| -100 | 0 | 2 | 6 |
| 100 | -0 | 0 | 0 |
| -100 | -100 | 3 | 10 |
| 100 | -100 | 6 | 19 |
| 100 | 100 | 2 | 8 |
| -100 | 0.375 | 7 | 23 |
| -100 | 1 | 4 | 14 |
| -100 | 0 | 6 | 20 |
| -100 | -1 | 5 | 15 |
| 100 | -0 | 0 | 2 |
| -100 | -100 | 4 | 13 |
| 100 | -100 | 6 | 18 |
| -100 | 100 | 0 | 1 |
| 100 | 0.125 | 2 | 7 |
| 100 | 0.25 | 3 | 11 |
| 100 | 0 | 5 | 16 |
| 100 | 0 | 7 | 22 |
| 100 | 1 | 1 | 3 |
| -100 | -100 | 3 | 9 |
| -100 | -100 | 2 | 6 |
| 100 | 100 | 3 | 10 |
| 100 | 0.375 | 7 | 21 |
| -100 | 0 | 6 | 19 |
| _ | _ | 7 | 23 |
| _ | _ | 5 | 17 |
| _ | _ | 4 | 14 |
| _ | _ | 5 | 15 |
| _ | _ | 1 | 4 |
| _ | _ | 0 | 2 |
| _ | _ | 6 | 18 |
| _ | _ | 4 | 12 |
| _ | _ | 0 | 1 |
| _ | _ | 3 | 11 |
| _ | _ | 1 | 5 |
| _ | _ | 5 | 16 |
When attempting to use the GLTF data V-HACD throws an assertion error:
i < m_dim[0] && i >= 0 && j < m_dim[1] && j >= 0 && k < m_dim[2] && k >= 0
I'm guessing the vertex ordering is incompatible.