Real Time Path Tracing in the Viewport - A New Level of Photorealism
OTOY's 3D rendering tools, including Octane Render™ and Brigade™, are the premier rendering solutions for next generation 'path traced' games and films.
Path tracing significantly reduces the cost and complexity of high quality rendering by automatically generating effects traditionally handled through manual post processing – including spectral rainbows, lens flares, unbiased motion blur and depth of field.
“A year ago, path tracing was considered too expensive to be used even in high-end Hollywood blockbusters. Today, thanks to advances in GPU rendering, OTOY is bringing real time path-tracing technology to millions of artists by leveraging GPU hardware that costs only a few hundred dollars. This is a game-changer on any budget,” said Jules Urbach, CEO of OTOY.“Autodesk is the leader in 3D design software for film and video game production. We are incredibly excited about our partnership and proud to be bringing their industry leading tools to an ever-expanding market through our cloud solutions,” said Alissa Grainger, President of OTOY.
Another test in my never relenting quest for real-time photorealistic graphics. This time I was inspired by one of the first animations rendered with unbiased Monte Carlo path tracing. The animation was made by Daniel Martinez Lara from Pepeland in 1999 and can be seen here:
http://www.youtube.com/watch?v=VNyknZ2zrsM
It’s one of the first animations that uses Arnold, the Monte Carlo path tracing based production renderer developed by Marcos Fajardo, that is currently taking Hollywood VFX by storm: it was used in e.g. Cloudy with a Chance of Meatballs, 2012, Alice in Wonderland and the Assassin’s Creed: Brotherhood and Revelations CG trailers and is giving PRMan and mental ray a run for their money (probably making them obsolete soon, mainly because of ease of use and huge artist time savings). The animation shows a very lifelike clay figure coming to life. Despite the simplicity of the scene, the whole looks very believable thanks to physically accurate global illumination and materials and an extensive use of depth-of-field and camera shake.
In an attempt to reproduce that particular scene, I’ve used the animated Ogre model from a ray tracing demo developed by Javor Kalojanov which can be found at http://javor.tech.officelive.com/tmp.aspx. The Ogre model (which was created by William Vaughan) consists of 50,855 triangles and was also used in the excellent paper “Two-level grids for ray tracing on GPUs” by Javor Kalojanov and Philipp Slusallek (really great people btw, whom I've had the pleasure to meet in person recently. The conversations I've had with them inspired me to finally try triangles as primitive for my real-time path tracing experiments (instead of just spheres), which led to this Ogre demo. To my surprise, triangle meshes are not that much slower to intersect compared to spheres. I think this is due to the fact that the cost of primitive intersection is becoming increasingly smaller compared to the cost of shading).
The following videos show an animated Ogre path traced in real-time with real-time, per frame update of the acceleration structure of the Ogre’s 50k triangle mesh (watch in 480p):
Path tracing is performed entirely on the GPU, in this case a GTS 450 (a low-end GPU by today’s standards). The framerate of the walk animation is about 4 fps max on my card but should be around 15-20 fps on a GTX 580. The image converges extremely fast to a very high quality result (in about 1-2 seconds). The movement of the Ogre (translation, rotation, animation) is actually much more fluid in real life without Fraps, the overhead of the video capturing software almost halfs performance.
The images below were each rendered at 20 samples per pixel in under 2 seconds on a GTS 450 (it would take less then 0.5 seconds on a GTX 580):
Note the very subtle color bleeding from the ground plane onto the Ogre:
With a glossy floor:
If you’re interested in trying this scene out yourself, send me an e-mail at sam [dot] lapere [at] live [dot] be. A CUDA enabled GPU is required (minimum compute capability 1.1).
I’m planning to build a (very) simple game with this tech. The possibilities are really endless. We're on the cusp of having truly photorealistic games.
"We have fully working and VERY fast SSS ready for release in the next test version. It renders about as fast (a tiny bit slower) as a glossy specular material. And, it's unbiased/bruteforce SSS, eg no bias introducing photon grids or other precomputed approximations.
[...]
This is the prime new feature in the next test release, along with instancing support and FAST voxelisation, and another suprise feature, aswell as the soon to be publically released first of a series of new products, OctaneRender for 3DS Max."
"Bidirectional pathtracing (and PMC) should make renders like this one converge MUCH faster and bidirectional pathtracing + PMC is something we will be starting work on next, after 2.5 is out.GPU rendering is going to redefine every area of rendering from movies, animation, visualization and design to games, simulation and virtual reality. Truly the most exciting time for rendering in decades. I'm very happy that this paradigm shift is in full swing and that things are evolving at nauseating speed :-)
PMC + bidirectional will be ideal, it will be as efficient as the popular standard in CPU based unbiased engines (MLT+bidir), and this combined with the power of GPUs should really take things to a new level."
