restrict_xyz

[Yzichen]

GaussianFormer/model/encoder/gaussian_encoder/refine_module.py

Lines 47 to 53 in 3bf28d5

	if restrict_xyz:
	assert unit_xyz is not None
	unit_prob = [unit_xyz[i] / (pc_range[i + 3] - pc_range[i]) for i in range(3)]
	unit_sigmoid = [4 * unit_prob[i] for i in range(3)]
	if phi_activation == 'loop':
	unit_sigmoid[2] = unit_prob[2]
	self.unit_sigmoid = unit_sigmoid

Is your intention to limit the offset of gs to [2.0, 2.0, 0.5]? But why calculate the unit_sigmoid in this way? Where does the 4 come from?

[huang-yh]

Sorry for the confusion.

1. Yes, the optimization of the xyzs of Gaussians would be very unstable otherwise.
2. That is a heuristic design given that the maximum derivative of the sigmoid function is 1/4.