Jan

06-26-2008, 11:41 AM

Hi there

Small question: When i don't do back-face culling and am looking on the back-side of a triangle, and i want to rotate the light vector into the tangent-space of that triangle, i do need to invert the normal of the triangle.

The question is, do i also need to invert the tangent and bi-tangent or do they stay the same, when i use the same texture-coordinates to sample from the normal-map ? My data is too fuzzy to see whether one or the other is correct, so i thought i'd ask people who know for sure.

Thanks,

Jan.

Small question: When i don't do back-face culling and am looking on the back-side of a triangle, and i want to rotate the light vector into the tangent-space of that triangle, i do need to invert the normal of the triangle.

The question is, do i also need to invert the tangent and bi-tangent or do they stay the same, when i use the same texture-coordinates to sample from the normal-map ? My data is too fuzzy to see whether one or the other is correct, so i thought i'd ask people who know for sure.

Thanks,

Jan.