From 6f0d79543164304dd580fa4440267a7fffc8fe01 Mon Sep 17 00:00:00 2001 From: Jet Hughes Date: Thu, 30 Mar 2023 13:19:09 +1300 Subject: [PATCH] vault backup: 2023-03-30 13:19:09 --- content/notes/10-3d-Cameras.md | 40 ++++++++++++++++++++++++++++++++++ content/notes/cosc-342.md | 1 + 2 files changed, 41 insertions(+) create mode 100644 content/notes/10-3d-Cameras.md diff --git a/content/notes/10-3d-Cameras.md b/content/notes/10-3d-Cameras.md new file mode 100644 index 000000000..ca22325bd --- /dev/null +++ b/content/notes/10-3d-Cameras.md @@ -0,0 +1,40 @@ +--- +title: "10-3d-Cameras" +tags: +- lecture +- cosc342 +--- + + +CAMERAS AND PROJECTIONS +- Cameras project the 3D world onto a 2D image + - Input is 3D points: (𝑥, 𝑦, 𝑧) + - Output is 2D points: (𝑢, 𝑣) +![matrix|100](https://i.imgur.com/bMo02GG.png) + - What form should P have? +> [!INFO] need to apply a transformation to convert 3d coords to 2d coords +> P should be a 3 row and 4 column matrix + +WHICH CUBE LOOKS RIGHT? +![](https://i.imgur.com/sYpeZvX.png) +> [!INFO] each cube is a projection of 3d points onto 2d space. +> middle cube is perspective transformation +> left is isometric +> right is orthographic + +ORTHOGRAPHIC PROJECTION +- Simple way to go from 3D to 2D +- Delete one dimension! +- Deleting X projects to the X -Y plane +![matrix equation](https://i.imgur.com/J2fPAp5.png) +- This is not how our eyes work +> [!INFO] z coordinate is removed since the third column is zero + +PERSPECTIVE PROJECTION +- Our view of the world: + - Distant objects looks smaller + - Parallel lines in 3D converge in 2D +- The pinhole camera + - A simple, but useful, model + - There is a central point of projection (the pinhole, often a lens in reality) + - Light travels from the world, through the pinhole, to the image plane \ No newline at end of file diff --git a/content/notes/cosc-342.md b/content/notes/cosc-342.md index a3668c19b..758af0b60 100644 --- a/content/notes/cosc-342.md +++ b/content/notes/cosc-342.md @@ -27,6 +27,7 @@ tags: - [x] [[06-homographies]] - [[08-visual-tracking-and-matching]] - [[09-3d-geometry]] +- [[10-3d-Cameras]] # Info