2023.02.26

atmosphere

每个pixel 做不同的jitter来消除一些模式化的artifact， 外太空边界

some PBR demos

https://guardhei.github.io/2022/03/unity-srp-pbr/#:~:text=The%20classic%20Moving%20Frostbite%20to%20Physically%20Based%20Rendering,given%20their%20own%20improvements%20%28such%20as%20multiscattering%20compensation%29.

Important Sampling – Mipmap Filtered Samples

https://developer.nvidia.com/gpugems/gpugems3/part-iii-rendering/chapter-20-gpu-based-importance-sampling
基本原理是
if the PDF of a sample direction is small (that is, if the sample is not very probable), we want the sample to bring illumination from the environment map averaged over a large area(bigger mip level) thereby providing a better approximation of the overall integration.
Alt text
Alt text
但是为什么前面要加个1/2呢，因为是会对应到面积，边长的平方是面积，面积是4倍，边长是2倍
Alt text
这里也解释了为啥UE做reflection capture的时候要手动生成mip chain

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tag:

    缺失模块。
    1、请确保node版本大于6.2
    2、在博客根目录（注意不是yilia根目录）执行以下命令：
    npm i hexo-generator-json-content --save

    3、在根目录_config.yml里添加配置： 

      jsonContent:
    meta: false
    pages: false
    posts:
      title: true
      date: true
      path: true
      text: false
      raw: false
      content: false
      slug: false
      updated: false
      comments: false
      link: false
      permalink: false
      excerpt: false
      categories: false
      tags: true

刚柔并济<br><br>安适如常<br>