ACM S TUDENT C HAPTER M EETING ! Wednesday September 20, :00 – 3:00 PM Engineering Building 0012 T ERRAIN R ENDERING C OMPOSITE T EXTURES O BSTACLE A VOIDANCE Bill White will present an overview of several tutorials and panel discussions that took place at SIGGRAPH 2000 concerning research directions for the computer and video gaming industry. R ESEARCH D IRECTIONS IN C OMPUTER & V IDEO G AMES

The video gaming industry is booming! This year, for the first time, computer and video game revenue in the U.S. will exceed feature film revenue! Cinema-quality graphics have been achieved in affordable platforms, driven by advances in processor and memory technology.

Where does computer graphics fit in? Unfortunately, like the film industry, the computer game industry has limited resources (particularly time) for R&D. It relies instead on academia and game platform developers to provide the research that results in game advances.

What’s so different about games research? The momentum for graphics research in the past has come from applications in the film industry and the scientific community. Prioritized:  High quality images  Massive data sets Prioritized:  High quality images  Massive data sets Deprioritized:  Real-time processing  Inexpensive platform Deprioritized:  Real-time processing  Inexpensive platform Graphics research is being increasingly propelled by the video gaming and virtual reality industries. Prioritized:  High quality images  Massive data sets Prioritized:  High quality images  Massive data sets Reprioritized:  Real-time processing  Inexpensive platform Reprioritized:  Real-time processing  Inexpensive platform

Problem Area #1: Scene Complexity Unlike the simple games of yesteryear, modern games require multiple characters interacting in elaborate environments, with independent motion and (hopefully) realistic levels of detail. Approach A: Brute force modeling of vast numbers of polygons. Problem: Serious processing. Approach A: Brute force modeling of vast numbers of polygons. Problem: Serious processing. Approach B: Fast-processing, low-memory NURBS models of surfaces. Problem: Counterintuitive modeling. Approach B: Fast-processing, low-memory NURBS models of surfaces. Problem: Counterintuitive modeling. Approach C: Progressive meshes for continuous level-of-detail. Problem: Smooth interpolation. Approach C: Progressive meshes for continuous level-of-detail. Problem: Smooth interpolation.

Brute Force Large Poly-Count Display Tens of thousands of polygons rendered at once. The vertices of distant polygons might be merged to make larger, less detailed polygons. Active polygon list must be continually updated as player navigates playing field.

70,000 triangles 30,000 vertices 153 patches NURBS Surface Modeling Large models can be effectively stored in a fraction of the space and processed in a fraction of the time as polygonal models. Developing the vertex sets for such models is rather elaborate and counterintuitive.

Continuous Level-of-Detail Rather than using a single polygonal model for each object, use multiple models, displaying the more detailed one when the object is closer to the viewer. Artists are encouraged to composite multiple texture maps, to improve run-time performance by reducing retrieval time. This intensifies the problem of texture seams where the texture has been stitched together.

Problem Area #2: Realistic Behavior Having characters and objects within the game environment behave “appropriately” is a particular challenge to game developers. Physics in Games  How to efficiently program the laws of physics into a game? Physics in Games  How to efficiently program the laws of physics into a game? Emotion Synthesis How to mimic human behavior so characters not controlled by the player react in a seemingly emotional fashion? Emotion Synthesis How to mimic human behavior so characters not controlled by the player react in a seemingly emotional fashion? Steering Behavior  How to get large numbers of characters to behave like a group of individuals? Steering Behavior  How to get large numbers of characters to behave like a group of individuals?

Physics in Games Years of research in the field of scientific visualization have yielded several efficient methods for rendering rigid bodies and fluid dynamics. Everything gets a bit more complex when the game player is allowed to interact with the environment at will.

Steering Behavior Some game objects (enemy starfighters, attacking dinosaurs, etc.) tend to behave in “flocks” or “herds”, yielding behavior patterns that aren’t that difficult to program or that time-consuming to render. PursuitPursuit Obstacle Avoidance Neighbor Detection AlignmentAlignment Formation Cornering

Emotion Synthesis Having game characters react “emotionally” to the environment and the developments in the game’s storyline can greatly enhance the gaming experience. Programming the character to react to interactive (i.e., non- canned) stimuli can be incredibly difficult. One solution: Network multiple players together so each character is controlled by a separate emotion-driven player!