Re: Re: [GD-Consoles] transforms

[<ali...@nt...>]

> From: "R & D (GameBrains)" <res...@ga...>

> Excuse the follow-up question if it is naiive :-) but 
> without the angles, doesn't positioning code like physics
> become problematic?  It is easy to look at a car bouncing 
> off a guardrail and calculate a reflected angle and new 
> heading vector from an angle, but how would I go about 
> doing that with matrices only?

A matrix specifies 4 vectors: position, direction (local Z axis), up (local Y), and left/right (local X).  You can rotate a matrix about its "axes" by multiplying it with a rotation transformation matrix.  Perspective transform is another simple matrix multiply.  Almost everything else is just vector maths, no need to mess around with trig functions.


alistair