Repository navigation
Camera intrinsics overwritten #82
Description
Hi, I am trying to understand the Fast BEV projection code. I noticed that in the NuScenesMultiView_Map_Dataset2 , or more precisely in the NuScenesMultiViewDataset the camera intrinsics are overritten with the identity matrix. Why is that done? In the following pipelines this is not set back to the original values.
new_info = dict(
sample_idx=data_info['sample_idx'],
img_prefix=[None] * n_cameras,
img_info=[dict(filename=x) for x in data_info['img_filename']],
lidar2img=dict(
extrinsic=[tofloat(x) for x in data_info['lidar2img']],
intrinsic=np.eye(4, dtype=np.float32),
lidar2img_aug=data_info['lidar2img_aug'],
lidar2img_extra=data_info['lidar2img_extra']
)
)
Activity
arnoldfychen commentedon May 17, 2024
My understanding:
I guess the code owner wanted to re-establish the intrinsic item in lidar2img (used later in FastBEV's _compute_projection() for scaling) in NuScenesMultiViewDataset's get_data_info(), so, assigned it with an identity matrix, as you know, the value of a matrix doesn't change when the matrix multiply with an identity matrix, i.e., I@A = A
BaophanN commentedon Jan 3, 2025
I am also confused with this. Since I want to adopt FastBEV as a view transformer module using OpenLane-V2 dataset. In Openlane-V2, extrinsics are sensor2ego matrix. Can you help me clarify is it true that extrinsics from nuscnenes also use sensor2ego matrix?
venkataramanas1 commentedon May 13, 2025
Have you up the project ? can you provide me steps to build and run properly ?