SIGGRAPH 2011 Talks – Part 2

This is the second in a series of posts on the SIGGRAPH 2011 Talk program – Part 1 can be found here. These posts focus on talks with relevant content for real-time rendering researchers and practitioners, including game developers.

Building Blocks

One of the talks in this session looks relevant – KinectFusion: Real-Time Dynamic 3D Surface Reconstruction and Interaction describes the use of a Kinect camera to acquire real-time dense 3D models of an entire room and its contents, enabling some interesting augmented reality and interaction possibilities. The reconstruction appears to require a high-end GPU to achieve real-time performance so this isn’t something for current generation consoles, but it definitely could be feasible on future platforms. It may also be interesting in the context of digitizing real-world objects as part of the film or game modeling process. The authors are from Microsoft Research Cambridge, except for one from Imperial College London.

Walk the Line

Two academic research talks in this session are potentially relevant for games and other real-time applications that use stylized rendering or deformations:

  • Parameterizing Animated Lines for Stylized Rendering – this talk describes a paper from the 2011 NPAR (Non-Photorealistic Animation and Rendering) conference (which is co-located with SIGGRAPH this year). It shows a way to have details along an outline track the geometry cleanly as the scene animates in 3D. Material from the NPAR paper can be found here. The authors are from École d’Ingénieurs Télécom ParisTech, except for one from Adobe.
  • Multiperspective Rendering for Anime-Like Exaggeration of Joint Models – this talk describes a more unusual type of stylization, where the model deforms in a stylized way as it animates, inspired by anime visual conventions. The authors are from Hitachi, except for one from The University of Tokyo.

1000 Points of Light

This session contains one game talk, as well as two relevant CG feature animation talks:

  • Lighting Tokyo for Pixar’s “Cars 2” – rendering cities at night is challenging (definitely for games, but even for CG feature animation) due to the extreme dynamic range and large number of lights. Tokyo, with its massive quantities of illuminated billboards and neon signs, is one of the most famous and extreme examples of this type of lighting situation. This talk covers the techniques used by Pixar Animation Studios to light a stylized version of nighttime Tokyo for the movie Cars 2 – note that the speaker will also present a Studio Talk on a similar topic.
  • “Megamind” – Lighting Metro City at Night – this task covers a similar challenge as the previous one, but with a distinct set of solutions from a different company (DreamWorks Animation) for a different film (Megamind).
  • Deferred Shading Techniques Using Frostbite in Need for Speed The Run – this talk will cover the tile-based deferred lighting architecture used in the Frostbite 2 engine, with emphasis on the PS3 implementation as used in the Electronic Arts game Need for Speed The Run (the talk was originally intended to cover the XBox 360 and Battlefield 3 as well, but has been refocused – the removed material will be covered in more depth in this course). It makes for an interesting combination with the previous two talks since it will show how the current state-of-the-art in game technology solves a similar problem as film (albeit at smaller scale) in real time.

Fur and Feathers

The three CG feature animation talks in this session cover fur and feather techniques which are too computationally costly to be feasible for most real-time applications today. They also don’t seem amenable to “animation baking” precomputation approaches since the resulting data would most likely be too heavy. However, these techniques should be able to run in real-time on future hardware platforms, making these talks of interest to forward-looking real-time researchers:

  • Quill: Birds of a Feather Tool – this talk describes a specialized pipeline developed by Animal Logic to procedurally model, animate and simulate feathers while avoiding intersections and rendering at various levels of detail.
  • Dynamic, Penetration-Free Feathers in “Rango” – somewhat similar to the previous talk, but focusing more narrowly on interpenetration avoidance and from the perspective of a different company (Industrial Light and Magic).
  • Accurate Contact Resolution for Interpolated Hairs – another ILM / Rango talk, but focusing on a different problem – handling collision between hairs and other geometry. The solution needed to be very fast and cheap since it was intended for use on interpolated hairs (it is common in CG feature animation and VFX to fully simulate a relatively small number of “guide hairs” and then interpolate a much larger number of cheap “interpolated hairs” between them).

Mixed Grill

This session contains two film talks, one game talk, and one academic research talk; all four are relevant:

  • The Power of Atomic Assets: An Automated Approach to Pipeline on “Legend of the Guardians: The Owls of Ga’Hoole” – games and movies share the challenge of structuring a production pipeline (software tools as well as workflow practices) to handle large numbers of assets. This talk will describe the system used at Animal Logic to handle the assets for the film Legend of the Guardians: The Owls of Ga’Hoole.
  • Animation Workflow in Killzone 3: A Fast Facial Retargeting System for Game Characters – handling facial motion capture data is tricky, especially retargeting to (possibly multiple) in-game models. This talk describes a technique used by Guerrilla Games to animate a large number of different faces for the extensive cut-scenes in the game Killzone 3.
  • Adaptive Importance Sampling for Multi-Ray Gathering – importance sampling (basically sampling a function more densely in areas that are estimated to have higher impact on the result) has recently become a key technology for production rendering. There was a whole SIGGRAPH course about it last year, and Pixar has added native support to the latest version of Renderman. Importance sampling is typically thought of as a ray tracing technique, but it is also important for image-based lighting (IBL) sources such as environment maps. Importance-sampled IBL is currently useful for game light baking tools, and is likely to be done in real-time on future platforms. This talk describes importance sampling improvements developed at Rhythm & Hues. Talk materials including an abstract and movie are available here.
  • High-Resolution Relightable Buildings From Photographs – efficient digitization of real-world scenes and objects is useful for both film and game development. Tools such as Crazybump are widely used in the game industry to infer relightable surface details from photographs, but do not always work as well as could be hoped. This research talk looks like it could offer some improvements in this area, making it of wide interest. The authors are from The University of Manchester, Loughborough University, and Dolby Canada.

From the Ground Up

All three CG feature animation talks in this session are relevant for game developers:

  • We Built This City: Big City Design and Implementation in “Kung Fu Panda 2” – games and movies sometimes contain large urban environments, which are very difficult to construct within reasonable time and staffing constraints. This talk will detail how DreamWorks Animation solved this problem for the film Kung Fu Panda 2.
  • The Visual Style of “Legend of the Guardians: The Owls of Ga’Hoole” – finding a good visual style is another difficult task shared by film and games; my feeling is that films tend to have more established processes for look and style development. This talk will detail the visual style established by Animal Logic for the movie Legend of the Guardians: The Owls of Ga’Hoole. I saw a similar presentation at FMX 2011, and it was full of interesting and relevant content.
  • Clouds in the Skies of Rio – in most games and films, clouds are off in the distance and can be handled with straightforward methods. But sometimes the camera needs to get up close and personal with the clouds, which can pose some interesting modeling and rendering challenges. Although cloud rendering techniques used in film can rarely run in real-time on current platforms, the way in which the clouds are art-directed and authored can be of interest. This talk discusses how Blue Sky Studios handled cloud authoring and rendering for the movie Rio.

Directing Destruction

Mixing simulation with manual control to create large, physically-believable and art-directed effects is a tough challenge which VFX and CG feature animation professionals have been focusing on for some time. The techniques used rarely lend themselves to real-time computation on current hardware. However, in many cases these effects can be pre-computed, and on future hardware they are likely to run in real time (perhaps with some reduction in scale). The four talks in this session discuss various case studies of this type:

  • End of Line: Character Destruction in “Tron: Legacy” – this talk discusses the tools developed by Digital Domain for the character destruction effects in Tron: Legacy.
  • Kali: High-Quality FEM Destruction in Zack Snyder’s “Sucker Punch” – in this talk, The Moving Picture Company discusses a finite-element simulation toolkit developed in partnership with Pixelux, with examples of its use in the film Sucker Punch. It is interesting to note that the tool is based on the same Digital Molecular Matter technology used in the games Star Wars: The Force Unleashed and Star Wars: The Force Unleashed II.
  • Directing Hair Motion on “Tangled” – this talk discusses the system developed by Walt Disney Animation Studios to animate the main character’s hair (almost a character in itself) in the movie Tangled.
  • Choreographing Destruction: Art Directing a Dam Break in “Tangled” – another Tangled talk from Walt Disney Animation, this one describes the way in which a complex water and rigid body simulation was art-directed for the “dam break” sequence.

Crowds

Scenes with large crowds are another differentiating factor between film and games. Sufficiently large crowds pose authoring and rendering challenges even for film; the solutions to these may be of interest to game developers working with smaller real-time crowds on next generation platforms. The three talks in this session discuss crowd case studies from three CG animated feature films:

  • Crowds on “Cars 2” – this talk discusses how Pixar Animation Studios improved their production pipeline to enable higher productivity when managing assets and controlling agent behaviors for Cars 2 crowd shots.
  • Synthesizing Complexity for Characters and Landscapes in “Rio” – this talk covers the systems used at Blue Sky Studios to procedurally generate large varied crowds of people and flocks of birds for the movie Rio, as well as the renderer enhancements done to efficiently ray-trace the resulting massive geometric detail.
  • Staging Carnival: Ray Tracing Crowds in “Rio” – another Blue Sky Studios talk about Rio, this time focusing on a specific case study (the carnival crowds).

There are eight more Talk sessions with relevant content, which I will cover in a subsequent blog post.

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