Dataset question

[sobikim]

Hi. Thank you for the great work!

I want to train MeshRCNN on a custom dataset.
When creating a dataset, if I know the focal length and sensor size of the actual camera, can I calculate "rot_mat" and "trans_mat" using those values? (Are "rot_mat", "trans_mat" only used to convert 3D model to 2D in MeshRCNN?)
Or should I assume sensor width=32mm and calculate "focal_length", "rot_mat", "trans_mat" like Pix3D dataset?
(Are "rot_mat" and "trans_mat" used in MeshRCNN besides converting 3D model to 2d?)

I would be very appreciate if you have time to reply.