Realtime raytracing a possibility?

[omega329]

http://graphics.cs.uni-sb.de/~woop/rpu/rpu.html
Interesting reading, appears to be from 2 1/2 years ago and running on a 66Mhz processor, frame rates are terrible, 1.2-10 FPS (but I'm used to that on freespace!). Given the state of modern technology, I think it may actually be possible to get realtime raytracing going in the gaming industry.

[mdhay]

It might happen. Hell, a 1900's officer once said: "Planes have no military value". Look at 'em now. ;)

[omega329]

In my opinion, it's less a question of if... and more a question of when.

[Linchpin]

Oh it will definitely be happening in the near futre , but not on this generation of consoles that's for sure . With Nvidia's buy out of Mental Images , the developers of the powerful and widely used production off-line renderer Mental Ray , I'm sure that real time Ray tracing will be the first thing that is on its way from this newly formed real time and off-line rendering partnership , in terms of fast real time raytracing capable hardware .

As for the previous link you posted with regards to that real-time raytracing engine, it isn't particularly high end .. the reflection and shadow raycasts are only using 4 rays in total for the sampling of the scene , so that means there can only be a total of 4 raytrace calculations per sample . So if a reflection needs a trace depth of 3 which would translate it to reflecting another reflective surface which is also reflecting another object and displaying reflective color information, then there can only be one trace depth calculation left over for the shadows so that means you cant have 2 shadows overlapping each other , or a shadow overlapping a reflection .. so as you'll notice in the scene with the car , the poles around it aren't casting shadows , as the car is clearly using a reflection trace depth of 3 for raytrace calculations ( reflecting the pole which is reflecting the sky ) .. So in effect only allowing one basic shadow cast which is from the car .

And I mean lets face it those effects arn't that amazing , it doesnt make you go wow holy cow those reflections are way better than enivonment mapped reflections . I mean how often will a gamer come across a refletive surface in game and take enough time to examine it to tell whether it is using an environment map or not , current gen game engines can hack up realistic reflections pretty well .

Taking triangles and tracing rays against them is really expensive in terms of rendering .Many production and visual effects companies steer away form using ray tracing even for their powerful off-line rendering render farms because of how resource hungry it is , they do use it , but not all the time . The classic way of raytracing of taking triangles and tracing rays against them wont necessarily be used for real time raytracing , as with the recent developments amongst the great minds of realtime rendering like John Carmack who are coming up with different methods of ray tracing such as "sparse voxel octree" raytracing which retrieves raycast information from compressed triangle data and also hybrid rendering which uses both the current rasterization methods mixed with sparse voxel octree ray tracing .

You can read an interview with John Carmack on the matter here http://www.pcper.com/article.php?aid=532&type=expert&pid=1
As John Carmack states perfectly ray traced shadows isn't a priority in current real time ray tracing as the current raster based shadowing methods can imitate them pretty well and render them a hell of a lot faster , and as for raytracing 3 reflection bounces or more realistically you can also hack those pretty cleverly in games with using multiple enviropnment maps , ray traced reflections isn't something that makes you truly go wow that is way better than the curent generation of graphics or non ray-traced rasterizing methods.
What John Carmack wants to do besides the obvious realistic reflection bounces route is to use raytracing to squeeze in much more texture detailing and for having a limitless geometry restricted game engine .

I think we will only see true ray tracing engine based games in the next 5 or so years on newer console systems , or on high end pc's a year or so before that .

[Darkdrium777]

PS3 real time raytracing (http://ca.youtube.com/watch?v=oLte5f34ya8)

We're definitely getting there. :)

[omega329]

It's three PS3 linked together, and the scene doesn't look complex enough for a game to be made from it.:| From that I'd expect realtime Raytracing to become a reality on the PS4

[Lance]

While real-time ray-tracing is possible, it is very very improbable that it will be actually used in games, for the simple reason that it is far less efficient than the methods currently in use, hence slower for any given level of chip performance. The competitive drive to get higher and higher levels of graphic excellence in games as a sales tool will keep the most efficient method in use, even though Intel is doing a lot of promotion in the media in an attempt to convince others to buy their own ray-tracing hardware. This argument has been much discussed at slashdot in recent weeks.

[Linchpin]

Yes the classic method of raytracing most probably wont appear in games . Intel is pushing for hardware and raw processor powered classic ray tracing methods which are very inefficient as compared to the advanced rasterizing methods used today . However the new type of real time raytracing and rasterizing/ray-trace hybrid methods that John Carmack mentions will probably be in use with game engines by the time the next generation of consoles are out.