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aharley / simple_bev

A Simple Baseline for BEV Perception
MIT License
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What is the use of xyz_camB? #33

Open sithu31296 opened 1 year ago

sithu31296 commented 1 year ago

Hello, I want to know why need to calculate xyz_camB in thisline and what is z after that line? And another is why the vertical dimension is Y instead of Z?

Please enlighten me!

aharley commented 1 year ago

In that context, camB is the camera where we captured the image, and camA is the camera which defines the 3D/BEV grid. (The 3D grid faces the same way as this camera.) We compute xyz_camB so that we can collect z from it (i.e., depth), and then collect bilinear samples for 3D points which have positive z values.

For your second question: I use Y for vertical because that's the standard I learned in computer vision: X=right and Y=down (in an image), and Z=forward (aka depth).