|How To Make A Virtual Camera Viewing System|
HTML-Version by Azure
The following algorithms describe how to create a "virtual camera" viewing system in which you have a camera positioned anywhere in a 3D world pointing to an arbitrary focus point. Camera Z panning (roll) is also possible by defining a direction vector.
O = observer position (camera) A = aimpoint position (focus) R = direction point position (up) N = normalize (Ax - Ox, Ay - Oy, Az - Oz) D = normalize (Rx - Ox, Ry - Oy, Rz - Oz) V = D - (D . N) * N U = cross product (V,N) | Ux Uy Uz | View Matrix = | Vx Vy Vz | | Nx Ny Nz |Before rotating, you must translate all points so that their origin is point A ; after rotating you must translate the Z offsets using the distance from point O to A, ie. the length of the N vector before normalizing.
Note that "." means dot product and "*" means multiplying each component of the N vector with the dot product. (scalar / vector multiplication)
I use the above algorithms in my 3D engine and they work perfectly.
Thanks must go to Silver Eagle/Pygmy Projects, Celebrandil/Phenomena and Scout/C-Lous for their (kind) support.