Thorsten Froehlich wrote:

> No, you are wrong.  The terms forward and backward ray tracing refer to the
> direction you follow the photons.
> In this sense photon mapping qualifies as forward ray tracing (if I
> understand how works correctly).

This is true - forward ray-tracing is the same as in the real-world where photons
leave a light source, interact with objects and go off to infinity or are
effectively destroyed (absorption) by objects, POV-Ray approximates this using
backwards ray-tracing, which most people tend to think of as the only kind of
ray-tracing or regular ray-tracing.
I saw this thing on some science show in Oz where a student had used regular
ray-tracing (forward) to show what moving at the speed of light would look like -
he made the speed of light really slow for this (1 m/s), and found that moving
objects seem to bend, and contract in really weird ways

See http://www.abc.net.au/quantum/stories/s118127.htm
Make sure U visit the link at the bottom of the page

Apart from that and MegaPOV photons I don't know of any examples of forward
ray-tracing - probably because it is so damn slow.

Pabs

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