DmitryM

08-01-2009, 08:59 AM

For each face of the mesh I'm calculating the quaternion representing the tangent space derived from UV coordinates.

Then I'm calculating mean quaternion of the faces that share a vertex. This is another big problem, but not major to this topic. For now it's just an arithmetic mean (sum divided by number).

Now I have a normal specified by graphics artist that must represent the axis for the resulting tangent space of the vertex.

The problem is: how to calculate the angle for this quaternion to have it as close to the target quaternion (calculated from faces) as possible?

Then I'm calculating mean quaternion of the faces that share a vertex. This is another big problem, but not major to this topic. For now it's just an arithmetic mean (sum divided by number).

Now I have a normal specified by graphics artist that must represent the axis for the resulting tangent space of the vertex.

The problem is: how to calculate the angle for this quaternion to have it as close to the target quaternion (calculated from faces) as possible?