Raytracing FPS

0.00001 fps !!

Unless your code is extremely severely and totally optimized !! B

But in certain cases, you can do it nearly
realtime (say 15-20fps and even 30fps), but you must limit
the number of effects, the raytracing depth to 1 or 2 and
no antialiasing at all !!!

It depends on the scene, the number/kind of effects and the raytracer itself.
You will find more informations about it with the search function and at www.openrt.de .

www.realstorm.com/
http://www.demoscene.hu/~picard/h7/

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Original post by programering what's the fps for raytracing?

same as the kmh for a vehicle.

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Original post by Trienco Quote: Original post by programering what's the fps for raytracing? same as the kmh for a vehicle.

Hehe :)

The last one I tried managed to run smoothly on my old 386 computer..it was called Wolfenstein 3D

Wolfenstein 3D and Doom use "Ray-Casting" not exactly "Ray-Tracing". Ray Casting is a subset of ray tracing, it is faster because it uses geometric contraints (walls and floor are always perpendicular).

"The last one I tried managed to run smoothly on my old 386 computer..it was called Wolfenstein 3D" Luctus

OMG

Ray-Tracing is pretty much never used for animating a game. The time it takes is simply too long. Depending on the complexity of the scene being rendered, a ray trace can take anywhere from a few seconds to a few hours. The problem is that raytracing provides a lot of realism at the expense of speed. Therefore, games tend to use less intensive techniques. Raytracing is mainly used for art or animations which can be produced in advance. Real-time in-game rendering must be handled by something more efficient.

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Original post by unreason Ray-Tracing is pretty much never used for animating a game. The time it takes is simply too long. Depending on the complexity of the scene being rendered, a ray trace can take anywhere from a few seconds to a few hours. The problem is that raytracing provides a lot of realism at the expense of speed. Therefore, games tend to use less intensive techniques. Raytracing is mainly used for art or animations which can be produced in advance. Real-time in-game rendering must be handled by something more efficient.

its your last phrase i disagree with.

'something less advanced' would be better, since raytracing is actually much more efficient in terms of time complexity.

if even half as much effort was put into hardware raytracing as in hardware rasterization, people wouldnt even know anymore what rasterization was.

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If ray tracing was really that much more efficient, some company would have come out of nowhere and ripped both ATI and NVIDIA a new one. Since it hasn't, we can probably conclude that ray tracing just isn't the best tool for the job. :)

hmm, if everybody thinks as you do, it's pretty obvious there will never be any company coming-out-of-nowhere-and-ripping-nv/ati-apart with a realtime rt hardware.

it's just a financial risk that big companies can't or don't want to take, the easier-short-term-highest profit way seems to almost always be the choosen one :/

I have to agree with sBibi. The big companies arent going to shell out the money to completely change their rendering pipeline its too expensive, just look at the automobile industry you wont be seeing a water powered car for a long time regardless of whether the technology is there or not.

Sorry, AP above was me.

Raytracing hardware could just support triangles, and use those to simulate all other primitives. Special primitives are not really that useful anyway; it's quite complicated to build arbitrary scenes with torii, spheres, cylinders and so on, even if you use CSG.

Using raytracing would however solve a lot of problems: Reflections, refractions, shadows (even real soft shadows) all come with the basic algorithm. And as scene complexity increases, the gap between raytracing and rasterizing quickly closes.

The reason that NVidia & ATi are not supporting raytracing yet is the fact that all games use polygon engines. Switching to raytracing now would also mean dropping backward compatibility. If someone finds a way to raytrace data that is meant to be rendered on a rasterizer, or the other way round, it might happen.

BTW there are already raytracers that are implemented in hardware. And I think future pixel shaders will support raytracing even better.

I don't see why you portray the "big companies" as being opposed to ray tracing. The fact is that these companies have a lot of very smart people who think about these things all the time. Why do you think nvidia gives gazillion dollar fellowships to guys like tim purcell?

Now they just aren't going to replace rasterization. You can't just expect the next gen of cards to just support glBegin(GL_RAY_TRACING) out of the blue. They are doing it gradually with programmability. Features like pixel shader branching are absolutely critical for a gpu ray tracer. If Pixar still does rasterization for first-hit visibility, chances are the real-time guys will be doing so for at least ten years to come.

PS. I was the AP above who came to the defense of poor innocent rasterization. Need to work on my logging in skills.
PPS. I love how this thread got started with a completely inane question like "what's the fps for raytracing"
PPPS. The answer is 42.

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Original post by Pragma I don't see why you portray the "big companies" as being opposed to ray tracing. The fact is that these companies have a lot of very smart people who think about these things all the time. Why do you think nvidia gives gazillion dollar fellowships to guys like tim purcell?

not opposed to it bcause theyre evil, or think raytracing is evil: its just that they have a whole load of factories, customers and an entire game development industry built around rasterization.

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Now they just aren't going to replace rasterization. You can't just expect the next gen of cards to just support glBegin(GL_RAY_TRACING) out of the blue. They are doing it gradually with programmability. Features like pixel shader branching are absolutely critical for a gpu ray tracer. If Pixar still does rasterization for first-hit visibility, chances are the real-time guys will be doing so for at least ten years to come.

yeah i also wonder whatpixars reasons are for this. first hit acceleration is a waste of effort in any even slightly complex scene, since the first hits only make up a small part of the total workload.

also, i dont think gradually introducing raytracing trough pixel shaders is very likely. raytracing can benefit hugely from fixed pipelines, and an architecture specificly designed for raytracing. besides raytracing doesnt really need that much of a programmable pipeline, since the basic algorithm does everything you want without having to hack away at it.

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Original post by Eelco yeah i also wonder whatpixars reasons are for this. first hit acceleration is a waste of effort in any even slightly complex scene, since the first hits only make up a small part of the total workload.

I get the impression from talking to artists that production rendering tends to use ray tracing very sparingly. To continue using pixar as an example (since renderman seems to set the trends in graphics), they use shadow maps for shadows. So as far as I can guess the only objects which they actually do any ray tracing on would be stuff like mirrors.

Another major advantage of rasterization to consider in this context is that it is much clearer how to support micropolygon rendering in a rasterizer than a ray tracer. I suspect this is a main obstacle in making a renderman implementation that works purely with ray tracing. It believe it's been done, but I honestly have no idea how this can be done efficiently.