Before I set off on another completely uncharted journey, I thought I’d ask…
If in a 3D game I’ve decided all the scenery is going to remain in the same position and I’m going to move the camera around, do I need to use the CreateLookAt and create an imaginary point on a sphere around ‘me’ in space to LookAt? If that’s the case can I simply use a projection or normalised copy of my rotation vector?
Create look at takes a Target Position in your world so yes you can just rotate a point around with some matrices then add that to the cameras position then pass that back to the CreateLookAt function as the Target Vector.
You can alternately just create a matrix with create world or any of the rotation methods and grab the forward from it to add to your cameras position then pass it to create look at.
The two methods are a little different CreateWorld takes a Forward Vector as if its just a direction were CreateLookAt takes a actual position to look at in world space and figures out the forward direction by comparison to the previous position you just gave it.
CreateWorld is for creating (world) objects orientation matrices in world space for all your game objects that are typically drawn, However this can include the camera as if it were a physical object in your world that moves and looks around though the camera is typically not drawn.
CreateLookAt is for creating the special requisite (view) matrice that typically endures for a single frame unchanged, from one of those objects that acts as your camera.