Say i have 3 vectors (Left, Up and In)representing a rotation matrix that is my spaceship orientation. And a vector (Pos) that represents position in 3d space.

How do i adjust the position vector to move the spaceship forward along the local z vector?

I tried this code but it doesn’t work properly:

//Move ship

Vector v(In.x, In.y, In.z);

v.Scale(flight_speed);

Pos += v;