Hm, okay. Thanks for your feedback.

So you suggest using normal transformation functions instead of LookAt, right? But this approach doesn't work, either. The first snippet I posted contained the MatrixTransform function. It was wrong at first, but JSoftware provided us with a new matrix and I modified the code. Nevertheless, the effect is still far from what's desired.

Maybe it's something wrong with the shader? Maybe I'm looking for a bug in a wrong place?