Why multiple `1.414` in `FOV_to_intrinsic`?
LeoXing1996 opened this issue · comments
LeoXing1996 commented
The formulation of calculating focal
from FOV
is
focal = 1. / np.tan(0.5 * fov * np.pi/180.)
However, in FOV_to_intrinsic
, 1.414
is multiplied at last.
Lines 140 to 149 in 4930760
Can anyone explain this? Thanks a lot.
Roland commented
I'm wondering about this as well. 1.414 is approximately sqrt(2), which is the diagonal of a unit square. Perhaps they are normalizing by the diagonal here? But their doc (https://github.com/NVlabs/eg3d/blob/main/docs/training_guide.md ) says the intrinsics are normalized by the height and the width instead of the diagonal, so this might be a bug?