I understand that calulating tangents from vertices directly will be not efficient. But I’m scoping rather on the just matrix multiplication only. Because I’ve seen some artifacts, when the normals on the surface are inverted according to negative scale component of matrices (normals seems to be derived from tangents). When I’m changing the code responsible to this stuff (namely multiplaying tangents by the same matrices as the positions were multiplied, but with scale reverted to 1,1,1) the artifacts disappears, and everything (including shading also) looks fine.