Warp wrote:
> 
> Jim Kress <nos### [at] kressworkscom> wrote:
> > Got any suggestions how I would do this?  I've looked through the Internet
> > and have not been able to find an algorithum (or code) that would show me
> > how this is done.
> 
>   I have never read or thought about the details of raytracing a triangle,
> but the basic algorithm is:
>   1. Calculate the intersection point of the ray and the plane (eg. the
>      value t for P*t+D, where P is the starting point of the ray and D is
>      the direction of the ray).

I suppose you meant P + t*D  ?


>   2. See if the intersection point is inside the boundaries defined by the
>      triangle (the first fast test is if t<0, then the ray did not hit the
>      triangle).

There are some discussions about this topic in this thread:
http://groups.google.com/groups?th=53321682e5f42db6

This search may also be useful:
http://www.google.com/search?q=ray+triangle+intersection


>   3. You'll have to perform the test with *each* triangle in the mesh
>      (except the current one), unless you implement some space subdivision
>      algorithm, eg. an octree (but that would make the algorithm a lot more
>      complicated, though faster).
> 
>   I can't say right now how step 2 is implemented.
>...



Tor Olav

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