How to convert matrix4x4 to AffineXf3f?

[czc98]

Hi!
How should the rigidB2A parameter be set for the findSignedDistance function when there are two individual 4x4 matrices of the mesh?
I looked at the documentation but I'm not clear on the difference between matrix and affine.

[Fedr]

Hi,

Our Matrix4<T> struct has build-in conversion operator AffineXf3<T>() const. So you can easily convert Matrix4f m into affine transformation by typing AffineXf3f(m).

rigidB2A is the transformation from B-object space to A-object space. If you know the transformations of A and B in some common space, e.g. in world space:

AffineXf3f xfA;
AffineXf3f xfB;

then xfA.inverse() will be the transformation from common space to A-object space and you can compute:

AffineXf3f rigidB2A = xfA.inverse() * xfB;