Ok, my question - if I can sum up correctly is as follows:
How to generate a heightfield from the alpha component of a texture map, where parts of the map will be removed via. alpha test to leave holes (at some threshold - say zero in the alpha channel = invisible), without the alpha test removing bits of geometry that are `above sea level’ because the fragment is larger than the texel!
Thanks - !!!
http://www.thermoteknix.com/93288989/ogl.htm
[This message has been edited by Robbo (edited 04-03-2002).]