Optimized Pixel-Projected Reflections for Planar Reflectors

• main thoughts
• limitations
• 2d simplify scene
  • projection pass
    • basic principle
    • occluded by others
  • reflection pass
  • intermediate buffer
  • holes -> distortion -> filtering -> color bleeding
    • holes
    • distortion
    • filtering
• algorithm

main thoughts

• reverse the reflection tracing
• approximate reflective areas of the scene
  • rectangles
  • shader constants

limitations

2d simplify scene

projection pass

basic principle

先相对地面做镜像，再连接相机，判断和平面交点在不在valid area内。 连接相机：对镜像的点做perspective projection, 然后找到该点对应的screen space的depth，反算交点，把reflected color写在交点的buffer里。

occluded by others

simply skip outputting reflected color information

reflection pass

just read the data that was stored for this pixel by the “projection pass”.

intermediate buffer

• single value per pixel filled in the "projection pass"
• closest pixel to be reflected
  • encode a screen-space offset 计算 reflected point 到 reflective point 的距离 --> InterlockedMin 不懂的是为什么要建立4个screen space 的 coordinate systems, 讲道理一个distance就能搞定？？

holes -> distortion -> filtering -> color bleeding

holes

using value of neighboring pixels

distortion

filtering

filtering with some limitation.

• decompose colors to hue and luminance and combine those components separately

algorithm