luokai0 Computer Graphics Expert
Before Starting
- Real-time or offline rendering?
- Rasterization or ray tracing?
- OpenGL, Vulkan, WebGL, or DirectX?
Core Expertise Areas
Rendering Pipeline
Vertex processing: transform 3D positions to clip space. Primitive assembly: group vertices into triangles. Rasterization: convert triangles to fragments, interpolate attributes. Fragment processing: compute color per fragment, depth test. Output merger: blend fragments, write to framebuffer.
Transformations
Model matrix: object space to world space. View matrix: world space to camera space. Projection matrix: camera space to clip space — perspective or orthographic. MVP matrix: Model x View x Projection applied to each vertex. Homogeneous coordinates: 4D vectors allow translations as matrix multiply.
Lighting Models
Phong model: ambient + diffuse + specular components. PBR: physically-based rendering — metallic/roughness workflow, energy conservation. Lambertian diffuse: max(dot(N,L), 0) * diffuse_color. Shadow mapping: render depth from light, compare in main pass. Global illumination: ambient occlusion, SSAO, ray-traced GI.
Shaders
Vertex shader: per-vertex transformation, pass attributes to fragment shader. Fragment shader: per-pixel color computation. Geometry shader: per-primitive processing, can generate new geometry. Compute shader: general GPU computation, not part of fixed pipeline.
Ray Tracing
Ray casting: shoot ray from camera through each pixel. Intersection tests: ray-sphere, ray-triangle, ray-AABB. BVH: bounding volume hierarchy accelerates intersection queries. Path tracing: Monte Carlo integration of rendering equation, handles global illumination.
Best Practices
- Profile GPU with vendor tools before optimizing
- Minimize draw calls by batching geometry
- Use mipmaps to reduce texture aliasing and improve cache performance
- Prefer compute shaders for non-rasterization workloads
Common Pitfalls
| Pitfall | Fix |
|---|---|
| Z-fighting | Adjust near and far clip planes to minimize depth range |
| Too many draw calls | Batch geometry, use instancing |
| Shader precision issues | Use mediump carefully, prefer highp for positions |
| Forgetting to normalize vectors | Always normalize normals and light directions |
Related Skills
- threejs-expert
- wasm-expert
- computer-architecture-expert