camera Intrinsics parameters：cx and cy are not used

[Dan-JIE]

Why are cx and cy not used in projection? Generally speaking, cx and cy affect the correspondence between pix and points. But in the source code, I found that cx and cy are not used at all. I would be very grateful if you can answer my doubts.

[AsherJingkongChen]

I assume that your cx and cy refers to intr.params[2:4], which are not used at all.

They should assume the center of the image as the principal point.

You can see the 2D points in NDC space are translated into screen space by half of the image size. See the rasterizer.