Pytorch3D Rendering 的一些疑难杂症


  1. 有了相机内参 K,而render又需要NDC坐标系,那要怎么定义相机?
  2. 图像的黄蓝色反了?
  3. render 完的图像锯齿很严重?怎么抗锯齿(Antialiasing)?
  4. 皮肤表面反光太强,光滑得像镜面一样,怎样更自然?
  5. 怎么物体只剩半截,更远的部分似乎被截掉了?
  6. 没解决的问题:PBR(physical based rendering)
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A camera is a mapping between the 3D world (object space) and a 2D image.

In general, the camera projection matrix P has 11 degrees of freedom: \[ P=K[R\ \ \ t] \]

Component # DOF Elements Known As
K 5 \(f_x, f_y, s,p_x, p_y\) Intrinsic Parameters; camera calibration matrix
R 3 \(\alpha,\beta,\gamma\) Extrinsic Parameters
t (or \(\tilde{C}\)) 3 \((t_x,t_y,t_z)\) Extrinsic Parameters

3D world frame ----- R, t ----> 3D camera frame ------ K -----> 2D image

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Difficult situations:

  1. The Academic page is powered by Jekyll, while the blog website is powered by Hexo.
  2. And they are maintained in two separated repositories on Github.
  3. Besides [username].github.io, I have a domain jyzhu.top, and want to use my custom domain.
  4. All in all, I hope to visit the academic page is at jyzhu.top, while visit the blog is at jyzhu.top/blog.

Now let's configure.

  1. Rename the blog repo as blog; rename the academic page repo as [username].github.io.

  2. Edit the blog's Hexo config file:

    url: https://jyzhu.top/blog
    root: /blog/

    While no need to move all the files into a subfolder blog of your repo.

    The Jekyll config is simple. Nothing needs to specify.

  3. Edit the Github repo settings. Set the academic repo's custom domain as jyzhu.top. A CNAME file will be automatically added in the root. Now obviously, the jyzhu.top successfully refers to the academic page.

    Then you know what, everything is done! Because all other repos with github page turns on, are automatically mapped to subpaths of [username].github.io by Github. Then coz [username].github.io is mapped to [url], everything will be there, including [url]/blog for the blog repo.

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