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GAP-LAB-CUHK-SZ / Total3DUnderstanding

Implementation of CVPR'20 Oral: Total3DUnderstanding: Joint Layout, Object Pose and Mesh Reconstruction for Indoor Scenes from a Single Image
MIT License
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The set up of camera coordinate system #4

Closed ysunbp closed 4 years ago

ysunbp commented 4 years ago

Hi! Can I ask a question in your paper? In your paper, it stated that: "We set up the world system located at the camera center with its vertical (y-) axis perpendicular to the floor, and its forward (x-) axis toward the camera, such that the camera pose R( ;) can be decided by the pitch and roll angles ( ; )." I do not quite understand how can the y-axis which is perpendicular to the floor be set while the x-axis is set towards the camera. In this case, the x and y-axis are not perpendicular if the camera is not looking at the horizontal direction. Or if the meaning of towards does not imply that the x-axis is parallel to the camera's optic axis, but just an axis that passes through the camera center and perpendicular to the y-axis defined. I am quite confused about this part. Could you please elaborate a bit? Thanks.

yinyunie commented 4 years ago

Hi, Yes, 'toward' here does not mean 'parallel'. The x-axis of the world coordinates passes through the camera center, perpendicular to the y-axis, and coplanar with the 'forward' axis of the camera and the y-axis (see the figure below). 1594480504(1)