DirectX 11 almost done!

[Eric Veteran]

Raytracing is slow on computers designed specifically for it. It would be unbearable on a cheap GPU.

[Kushan]

Raytracing is slow on computers designed specifically for it. It would be unbearable on a cheap GPU.

Raytracing is an interesting one. While yes, it's slower than rasterisation (the thing all graphics cards today use) in most cases, it's not affected as much by things like the number of triangles or reflections in a scene.

To put it in simple terms, when you rasterise a scene, you have to pretty much go through every single triangle in it and draw it in some way (there are ways to optimise this, of course). But with ray tracing, you "bounce" a ray off of the triangles until you hit a light source, then you stop.

What does this mean? Well, if you double the number of triangles in a scene, a rasteriser will only be able to draw half as many frames in the same amount of time. A ray tracer, however, only needs to bounce the ray a few more times. This means that there becomes a point when ray tracing is actually FASTER than rasterisation (We haven't quite hit that point yet, but we're not far off). What's more, ray tracing can do all sorts of groovy effects that rasterisation simply cant without some cheap tricks - such as real reflections (or portals, if you will).

[Borbus]

Ray tracing is by no means new, but I'm not sure if it has been done in real time before. Any high quality 3D renderer will use ray tracing but they can take hours for a single frame, hardly a decent fps :p

[Kushan]

Ray tracing is by no means new, but I'm not sure if it has been done in real time before. Any high quality 3D renderer will use ray tracing but they can take hours for a single frame, hardly a decent fps :p

Technically, wolfenstein 3D uses a special form of ray tracing called ray casting.

[The_Decryptor Veteran]

Ray tracing is by no means new, but I'm not sure if it has been done in real time before. Any high quality 3D renderer will use ray tracing but they can take hours for a single frame, hardly a decent fps :p

I can ray-trace a simple scene at 3-4fps (640x480)

And I'm on a low end C2D.

My graphics card can render simple scenes (a few objects) at 800x600 faster than my CPU can at 320x240.

[mildpanda]

haha, i been using ray tracing since... 3Ds Max 5 (i started with 5, so don't know about earlier versions... i guess this is a joke :p (april fool maybe)

[Kushan]

have you been using ray tracing in REAL TIME, at 30FPS or better, though?

[toadeater]

Good luck finding hardware that will run ray tracing faster than a slideshow.

This was developed by Intel for Nehalem, and later 8-core CPUs which will debut in 2010 or maybe late 2009. Intel wants physics and graphics done on CPUs instead of Nvidia and ATI cards. Games are ignoring CPUs lately and there's little reason to buy something like Nehalem unless Intel comes up with one. Good for us because we won't need new CPUs anytime soon, bad for Intel.

The only problem with Intel's plan is that ray tracing is ****ing slow. :laugh: Even 8-core CPUs still won't be enough for true realtime ray tracing of modern 3D games. This is not "simple scenes at 320x240." What Intel plans has to be some sort of "pseudo ray tracing," which won't be much more than an alternative to GPU-based graphics, only no game developer is going to use it because consoles won't use it.