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View Full Version : Where can i get the tutorials about ray tracing?



soso
04-15-2002, 09:56 AM
Where can i get the tutorials about ray tracing? Anyone can let me know that? Thanks.

davepermen
04-15-2002, 10:04 AM
well.. not here

but you can try in google.. or on flipcode there are discussionthreads about raytracing, often there are links in, too..

oh, and in every good mathbook with vector-geometry you get plenty of infos you need http://www.opengl.org/discussion_boards/ubb/wink.gif (ray-sphere ray-plane ray-whatever http://www.opengl.org/discussion_boards/ubb/smile.gif)

have fun searching, but not on opengl.org.. its the last place for raytracing..

V-man
04-15-2002, 02:54 PM
Real time raytracing should become part of everyday video cards someday. It's pretty much a guarantee that it will, and opengl will need to deal with that. glEnable/glDisable perhaps, glBeginScene/glEndScene


V-man

jwatte
04-15-2002, 06:36 PM
OpenGL isn't very well suited for submitting geometry to a ray tracer. Neither is Direct3D IM. You really need more scene graph information than that to do a decent job of ray tracing.

Maj
04-16-2002, 12:29 AM
Or something inbetween (http://www.openrt.de) .

Devulon
04-16-2002, 02:09 AM
There is one huge problem that ray tracing and other global illumination/drawing techniques. And that is the word global. Ray tracing requires access to the entire scene, fixed at a point in time. Lots of times in opengl models and even the environment are being generated and sent to the card as geometry is being greated. For example, skinned characters with skeletal animation. For it to be possible for a video card to do ray tracing it would require having all the geometry and all the textures and everything all at once. This is a little unreasonable even for a card with 128 Megs, even 256 for that matter. Doing something along the lines of quake/2/3 with a bsp and PVS would help a lot. The problem is that often a mirror (its reflection anyway) can see things that the camera can't. So you would have to be very careful about culling objects. In the end the majority of data would still be needed and we are back to the original problem of needing the entire world/environment all at once.

Its and interesting idea but for realtime it has a lot of problems. It requires too much memory and it tends to be quite slow. Ray Tracing is about building a high quality scene with "more correct" light object interaction. It really isn't about speed.

Devulon

AdrianD
04-16-2002, 05:59 AM
Actually, the newest hype to accelerate Realtime Raytracing is to use OPENGL.

if you want to learn more about realtime raytacing check out this sites:
http://www.acm.org/tog/resources/RTNews/demos/overview.htm
http://www.acm.org/pubs/tog/editors/erich/
http://www.cfxweb.net/article.php?sid=997&mode=&order=0
http://lycium.cfxweb.net/

this are sites where i got all the informations, that i needed to develop my own little raytracer (i just wanted to do this since i saw the first Reaytracer-pics on the Amiga.....loooong time ago)

imho in most cases RTR doesn't make any sence, if you have a GF3 or RADEON card.
but it's a very nice way to learn more about collisions/intersections and really good math optimizations.



[This message has been edited by AdrianD (edited 04-16-2002).]