Know thy ally

When developing a technology demo it's a question of whether the hardware manufacturer wishes to target the developer or the end-user – the difference between now and the future.

Demos intended for developers need to be realistic. They need to provide real-world examples of new technology features that can be incorporated into games immediately. NVIDIA classically has done a better job than ATI in this realm. With the GeForce4 launch, the Squid demo was intended to demonstrate the use of fluid simulation on the GPU itself. In fact, they were incorporating a fluid model only recently described at SIGGRAPH. Today games like Morrowind and Tiger Woods Golf incorporate on-GPU calculations for their water effects. Simulation of physical dynamics is something NVIDIA seems excited with. From a technical standpoint, 'Nalu' is one of the most exciting demos from the GeForce 6800 demo suite due to the complexity of the hair model and how it moves in water. 'Clear Sailing' features adaptively tessellated waves, dynamic calculations for the foam and splash. These demos provide developers with ideas on how to incorporate GPU-based physics simulation while simultaneously entertaining the end-user. Most NVIDIA technology demos are designed from this perspective. Of exception are the two best NVIDIA tech demos of all time, Luxo Jr. and the Final Fantasy: The Spirits Within. Neither of these are publicly distributable due to the licensing agreements with Pixar and SquareEnix, respectively.

The Far Side of the World? (Clear Sailing - NVIDIA)

ATI has also incorporated novel SIGGRAPH algorithms in their demos such as their 'Rendering with Natural Light' demo in the Radeon 9700, however in general, their demos have classically targeted end-users more often than developers. Even as far back as the Rage 128, when FiringSquad was just starting, ATI had commissioned 'Rage Dawning.' Animusic was the DX9 demo most Radeon 9700 users ended up showing off. While it certainly highlighted the polygon performance, shadowing, and phong shading techniques available on the Radeon 9700, it was the content that was cool. In order to sync the motion with the music, it's likely that the physics are all pre-calculated and so it's just the job of the GPU to make the graphics happen. Today, with 'The Doublecross,' the animation is motion captured. This not only makes it look more realistic but frees the GPU from physics simulation.

Ruby and Optico (The Doublecross - ATI)

No one expects gameplay graphics to reach the level of quality offered in 'The Doublecross' – today's hardware just cannot handle it. However, by showing off what the GPU can do when elements of the animation have been precalculated, they are showing gamers what the games of the future will look like as developers are able to take advantage of faster CPUs.

Comparative Advantage

While developing demos for developers is intellectually challenging and important for pushing software development in the right direction, the best tech demo is still going up against the unaligned interests between software and hardware developers. Even if the technology demo looks great and represents a feasible feature for current games, it will not have a substantial impact on the way games are developed – market forces still drive developers to maintain platform neutrality. The idea that a good demo will encourage developers to make more computationally demanding games leading to increased sales of a particular graphics card is flawed. Instead it just preserves an overall consumer interest in upgrading graphics hardware (of all manufacturers) as games progress in their complexity. For that reason, while developer-oriented demos will continue to be important, the emphasis should be placed on user-oriented tech demos.