I was wondering if it is possible somehow to find two orthogonal vectors on a mesh, but starting from screen space.
I know that I can bring two points (e.g. currPixel and currPixel + (1,0)) to object space if I have also depth info. In such way I can find a vector that is on the mesh in object space.
Now we all know that in 3D there are an infinite number of perpendicular vectors to another one so if I just take one of them I have no guarantee it would be on the surface of the mesh. Taking perpendicular vectors in screenspace is of no help as they may well map to non-orthogonal vector in object space.
Is it possible, starting from the data I have (persp. matrix, viewMatrix, modelMatrix, depth info and screenspace info), to obtain the said vector or is it an impossible task?
Edited by cifa, 12 August 2014 - 02:08 PM.