GAMES202 Lecture 01 - Introduction and Overview

I. Overview

A course at intermediate level: connecting basic knowledge and research
Real-Time High Quality Rendering
- Speed: More than 30 FPS, for VR/AR 90 FPS or above
- Interactivity: Each frame generated on the fly
Real-Time High Quality Rendering
- Realism: Advanced approaches to make rendering more realistic
- Dependability: All-time correctness (exact or approximate), no tolerance to (uncontrollable) failures
  - Requirement: No artifacts.
Real-Time High Quality Rendering
- What is rendering? Calculating light which human eyes perceive
  - 3D Scene -> Image

The topics are diverse: The course will be organized by topics.

4 Different Parts on Real-Time Rendering:

Topics:

Shadow and Environment Mapping
Interactive Global Illumination Techniques
Precomputed Radiance Transfer
Real-Time Ray Tracing
Participating Media Rendering, Image Space Effects, etc.
- Single scattering, image space reflection
Non-Photorealistic Rendering
- ~~Genshin Impact~~, the Legend of Zelda
Antialiasing and Supersampling
- TAA, DLSS
Chatting about tech and games

Generally speaking, not about a specific engine or API, and not quite about offline rendering.

3D modeling or game development, or specific API
- Using OpenGL
  - But when finishing assignments, basic knowledge of OpenGL is required.
  - Shader Language is important! GLSL, for example.
Expensive light transport techniques
Neural Rendering (Why?)
- Not high-quality: cannot do cheery-picking (as of when the course is being conducted)
- Cannot be real-time: computational cost too high
Specific optimization and high performance computing
- Purely technical.

Understand the different between science and technology
- Science: knowledge
- Technology: Implementing & Engineering. Requires skills that turn science knowledge into products

Real-time rendering:
- fast & approximate offline rendering + systematic engineering
Fact:
- in real-time rendering technologies, the industry is way ahead of the academia.
Practice makes perfect.

Computer Graphics is AWESOME!

As of now, current CG algorithms are able to generate photorealistic images
- Complex geometry, lighting, materials, shadows, ...
- Computer-generated movies/special effects (difficult or impossible to tell real from rendered)
But accurate algorithms (esp. ray tracing) are very slow:
- Therefore, the phrase offline rendering
  - Rendering 1 frame in Zootopia can take up to 10,000 CPU core hours
Proper approximations can lead to plausible results but run much faster

Interactive 3D graphics pipeline as in OpenGL
- Earliest SGI machines (Clark 82) to today
- Most of focus on more geometry, texture mapping
- Some tweaks for realism (shadow mapping, accum. buffer)
20 years ago - Into the Game Industry
- Interactive 3D geometry with simple texture mapping, fake shadows (OpenGL, DirectX)
10~20 years ago - Programmable Shaders
- A giant leap since the emergence of programmable shaders
- Complex environment lighting, real materials (velvet, satin, paints), soft shadows
Today
- Stunning graphics, extended to VR and even movies
In the future

Programmable graphics hardware (shader) (20 years ago)
- Compute Shader
Precomputation-based methods (15 years ago)
- Complex visual effects are (partially) pre-computed
- Minimum rendering cost at runtime
- Relighting
  - Fix geometry
  - Fix viewpoint
  - Dynamically change lighting
- Interactive Ray Tracing (8~10 years ago: CUDA + OptiX)
  - Hardware development allows ray tracing on GPUs at low sampling rates (~1 samples per pixel (SPP))
  - Followed by post-processing to denoise