Thursday, 16 December | 9:00 AM - 10:45 AM | Room E5

Presented in English / 영어로 발표 됨

Efficient Substitutes for Subdivision Surfaces in Feature-Quality Games

Wednesday, 15 December | 7:00 pm - 8:45 pm | Room E5

As real-time graphics aspires to movie-quality rendering, higher-order, smooth-surface representations take center stage. Catmull-Clark subdivision surfaces are the dominant higher-order surface type used in feature films, as they can model surfaces of arbitrary topological type and provide a compact representation for smooth surfaces that facilitate modeling and animation. But their use has been hindered in real-time applications because the exact evaluation of such surfaces on modern GPUs is neither memory nor performance efficient. The advent of DirectX 11, recent theoretical results in efficient substitutes for subdivision surfaces, and recent hardware advances offer the possibility to see real-time cinematic rendering in the near future.

This course covers the hardware tessellation part of the SIGGRAPH 2009 Course Efficient Substitutes for Subdivision Surfaces with the emphasis on character tessellation in movie-quality games. It adds additional material based on recent research findings and practical optimizations. The goal of this course is to familiarize attendees with the practical aspects of introducing substitutes in subdivision surfaces to increase efficiency in real-time applications.

The course begins by highlighting the properties that make SubD modeling attractive and introduces some recent techniques to capture these properties by alternative surface representations with a smaller foot-print. It lists and compares the new surface representations and focuses on their implementation on current and next-generation GPUs, then addresses crucial practical issues, such as watertight evaluation, creases and corners, view-dependent displacement occlusion mapping, and LOD computation. Finally and most importantly, it explains how these advanced techniques have been adopted into their gaming pipelines.



Intended Audience

Technical practitioners and software developers who use or intend to use subdivision surfaces in real-time applications.

Presentation Language

Presented in English / 영어로 발표 됨


Basic knowledge of geometric modeling algorithms, in particular subdivision surfaces, and some familiarity with the graphics pipeline of modern GPUs.


  Applications (character tessellation, ocean rendering, hair simulation, terrain rendering, etc.)
  Several Demos

Overview of Various Tessellation Schemes
  Phong Tessellation
  PN Triangles and PN Quads
  Approximating Catmull-Clark Subdivision Surfaces (ACC)

DirectX 11 Tessellation Pipeline & Tessellation Patterns

Sample CodeWalk-Through 
  Phong Tessellation Sample Code
  PN Triangles Sample Code
  ACC Sample Code

Practical Concerns
  Corners and Creases 
  Tessellation Factors

In Real Game: Metro 2033

Final Remarks

Q and A

Tianyun Ni
NVIDIA Corporation

Instructor Bios

Tianyun Ni is a senior graphics R&D engineer on NVIDIA's Developer Technology Team. She obtained her computer science from the University of Florida in 2008. She has published a number of papers on a variety of topics and regularly speaks at graphics and game development conferences around the world, including SIGGRAPH, GDC, etc.). Her most recent work involves finding applications for Direct3D 11 and developing advanced technologies to harness the computing power of next-generation GPUs.