Hello, in my project I have a model (a car) from which I want to compute a ray onto its x-axis. the position is actually (-10/0/0) and the direction vector is (1/0/0). Now I want to rotate the model for example 20° around the y-axis. I thought, I compute the new direction vector like this: dir.x = cos(20*pi/180); dir.y = 1.0f; dir.z = sin(20*pi/180); Is that right or am I doing it the wrong way? How should I do it otherwise? Thanks in advance!

The rotation formulas are incomplete. Look e.g. here for the complete formulas.