Nope. It's an interactive graphicsQuote:> Just a stupid question:

> Can OpenGL do Ray Tracing?

format. Immediate mode kind of prevents

any sort of ray tracing or ray casting

rendering, but you can do enough tricks

to make it look cool (like using

OpenGL lights to mimic radiosity; that's

cool stuff!).

-Mike

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"Back off man, I'm a scientist." -Peter, Ghostbusters

NoQuote:> Just a stupid question:

> Can OpenGL do Ray Tracing?

Basicly it can only do the rendering, with additions like stencils, light

and tesselation... etc...

Still pretty fancy tho...

The math for raytracing is extensive.... far to extensive for even a high

end PC, so even with OpenGL, you would end up with a single frame every 20

minutes...

19.99999 minutes to calculate the frame

0.00001 minutes for OpenGL to draw it

So there would be no speed increase in using OpenGL for raytracing, you

could just as well use the WinAPI SetPixel (orwhateveritsnameis), and you

wouldnt see any difference..

IMO ofcause ;)

Lars

>Just a stupid question:

>Can OpenGL do Ray Tracing?

You might want to use raytracing to produce realistic shadows and

reflections. There are many ways to simulate these effects in OpenGL without

raytracing.

OpenGL can be used as part of the ray intersection test. For example, the

scene can be rendered from the viewpoint, with a unique color assigned to

each primitive in the scene. This color can be read back to determine the

primitive intersected by a ray at a given pixel. If the exact geometry is

used in this algorithm, some aliasing may result. To reduce these aliasing

artifacts, bounding volumes could be rendered instead.

By changing the viewpoint and view direction, this algorithm can be used for

intersection testing of secondary rays as well.

A ray tracing application might also use OpenGL for display of the final

image. In this case, the application would be responsible for computing the

color value of each pixel. The pixels can then be rendered as individual

GL_POINTS primitives, or stored in an array and displayed via a call to

glDrawPixels().

-Paul Martz

Hewlett Packard Workstation Systems Lab

To reply, remove "DONTSPAM" from email address.

There is no OpenGL function for raytracing. Any lighting done is per-vertex,

and objects don't reflect light. Simple, yet effective and efficient.

However, you could use textures on every object, and then do your own

raytracing/raycastig computations. Each texture would represent the lighting

effect on your objects. Of course, it wouldn't be dynamic, but then again,

neither is raytracing.

I've used it myself to implement correct shadows on objects, but it isn't

dynamic.

Quote:> Just a stupid question:

> Can OpenGL do Ray Tracing?

> > Just a stupid question:

> > Can OpenGL do Ray Tracing?

> No

> Basicly it can only do the rendering, with additions like stencils, light

> and tesselation... etc...

> Still pretty fancy tho...

> The math for raytracing is extensive.... far to extensive for even a high

> end PC, so even with OpenGL, you would end up with a single frame every 20

> minutes...

> 19.99999 minutes to calculate the frame

> 0.00001 minutes for OpenGL to draw it

(Forget Quake3 over the Internet, now THAT's lag)

btw - Only kidding.

Quote:> So there would be no speed increase in using OpenGL for raytracing, you

> could just as well use the WinAPI SetPixel (orwhateveritsnameis), and you

> wouldnt see any difference..

> IMO ofcause ;)

> Lars

1. ANNOUNCE(POV-Ray): Ray tracing of trimmed rational surfaces

Hello,

I would like to announce new unofficial version of POV-Ray 3.02. This version

extends latest POV-Ray by ability of ray tracing trimmed rational (bezier)

surface patches. In addition it renders current "bicubic_patch" nearly at same

speed as method from official POV-Ray 3.02 but it does not require big ammount

of precomputed data. You can download source code of this patch from:

ftp://atrey.karlin.mff.cuni.cz/pub/local/0rfelyus/povray-3.02/

There are also binaries for Linux and MS DOS(compiled with DJGPP v2). Please

send me your comments, advices or reminders. Also I would like to see beautiful

pictures which you render with this version.

Dan

ps: if you are interested in algorithm I use than look at: Tomoyuki Nishita,

Thomas W. Sederberg and Masanori Kakimoro: Ray Tracing Trimmed Ratinnal Surface

Patches [proceedengs of SIGGRAPH '90; Computer Graphics, vol 24, Num 4, August

1990]

3. POV-Ray and volume ray tracing?

4. Paint Shop Pro vs. Picture It

5. Moray bundled with Ray Tracing Worlds with POV-Ray

6. FS: 3DS4, Animator Pro, Inside 3DS....Now Reduced!!

7. FS: BOOK - Ray Tracing Worlds with POV-RAY (book+disks)

8. manipulating bmp files in a database

9. Ray-z-Buffer Approach for Ray Tracing

10. Ray tracing: ray-object intersection

11. Ray-tracing using non linear ray...

12. Fastest way to generate eye rays in Ray Tracing

13. ANNOUNCE(POV-Ray): Ray tracing of trimmed rational surfaces

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