in shap_e/models/nn/pointnet2_utils.py [0:0]
def farthest_point_sample(xyz, npoint, deterministic=False):
"""
Input:
xyz: pointcloud data, [B, N, 3]
npoint: number of samples
Return:
centroids: sampled pointcloud index, [B, npoint]
"""
device = xyz.device
B, N, C = xyz.shape
centroids = torch.zeros(B, npoint, dtype=torch.long).to(device)
distance = torch.ones(B, N).to(device) * 1e10
if deterministic:
farthest = torch.arange(0, B, dtype=torch.long).to(device)
else:
farthest = torch.randint(0, N, (B,), dtype=torch.long).to(device)
batch_indices = torch.arange(B, dtype=torch.long).to(device)
for i in range(npoint):
centroids[:, i] = farthest
centroid = xyz[batch_indices, farthest, :].view(B, 1, 3)
dist = torch.sum((xyz - centroid) ** 2, -1)
mask = dist < distance
distance[mask] = dist[mask]
farthest = torch.max(distance, -1)[1]
return centroids