Our current backface culling code works 99.9% of the time. But it's clearly failing in edge cases
In La machine guns there is a giant missing poly in the floor
I thought it could have been a bad rom dump, or some other crazy error. However the poly data is there. It's just being backface culled.
Here it is marked in nik's debugging tool
Finding the actual rom model
All using the same matrix, so it's not a problem with the determinant
Flipping over the model
Oh hai there missing polygon >_<
Not sure how the hardware is doing the backface culling. Because some polys clearly we are meant to see their backfaces (for reflections etc). In my code I am calculate the matrix determinant, to see if the matrix flipped the poly winding, and if so to cull the vertices. But perhaps the h/w is doing something else.