From: Jon M. Taylor <taylorj@ecs.csus.edu>
  To  : ggi-develop@eskimo.com
  Date: Wed, 19 Aug 1998 18:11:28 -0700 (PDT)

Re: LibGGI3D RFC

On Wed, 19 Aug 1998, Neal Tucker wrote:

> > > > III. Design specifics.
> > > > 
> > > > * struct camera { float x1, y1, z1, x2, y2, z2 }. Every LibGGI3D display
> > > > will have a camera struct attached to it.  A generic hook for arbitrary
> > > > display data should also be present - the shaders might use it.  void
> > > > *private_data. 
> 
> I'm just skimming this thread, but this caught my eye...
> Don't you need at least three points to define a camera
> (i.e. position, view direction, top-of-head direction)?

	Yeah, I goofed.  Using three angles (theta, phi and alpha) do
define the viewing direction is better.  Technically, you also need the
dimensions of the viewing plane which will be mapped onto the 2D
framebuffer.

Jon

---
'Cloning and the reprogramming of DNA is the first serious step in 
becoming one with God.'
	- Scientist G. Richard Seed