""" Adapted from https://github.com/yanx27/Pointnet_Pointnet2_pytorch/blob/master/provider.py """ import numpy as np def normalize_data(batch_data): """Normalize the batch data, use coordinates of the block centered at origin, Input: BxNxC array Output: BxNxC array """ B, N, C = batch_data.shape normal_data = np.zeros((B, N, C)) for b in range(B): pc = batch_data[b] centroid = np.mean(pc, axis=0) pc = pc - centroid m = np.max(np.sqrt(np.sum(pc**2, axis=1))) pc = pc / m normal_data[b] = pc return normal_data def shuffle_data(data, labels): """Shuffle data and labels. Input: data: B,N,... numpy array label: B,... numpy array Return: shuffled data, label and shuffle indices """ idx = np.arange(len(labels)) np.random.shuffle(idx) return data[idx, ...], labels[idx], idx def shuffle_points(batch_data): """Shuffle orders of points in each point cloud -- changes FPS behavior. Use the same shuffling idx for the entire batch. Input: BxNxC array Output: BxNxC array """ idx = np.arange(batch_data.shape[1]) np.random.shuffle(idx) return batch_data[:, idx, :] def rotate_point_cloud(batch_data): """Randomly rotate the point clouds to augument the dataset rotation is per shape based along up direction Input: BxNx3 array, original batch of point clouds Return: BxNx3 array, rotated batch of point clouds """ rotated_data = np.zeros(batch_data.shape, dtype=np.float32) for k in range(batch_data.shape[0]): rotation_angle = np.random.uniform() * 2 * np.pi cosval = np.cos(rotation_angle) sinval = np.sin(rotation_angle) rotation_matrix = np.array( [[cosval, 0, sinval], [0, 1, 0], [-sinval, 0, cosval]] ) shape_pc = batch_data[k, ...] rotated_data[k, ...] = np.dot( shape_pc.reshape((-1, 3)), rotation_matrix ) return rotated_data def rotate_point_cloud_z(batch_data): """Randomly rotate the point clouds to augument the dataset rotation is per shape based along up direction Input: BxNx3 array, original batch of point clouds Return: BxNx3 array, rotated batch of point clouds """ rotated_data = np.zeros(batch_data.shape, dtype=np.float32) for k in range(batch_data.shape[0]): rotation_angle = np.random.uniform() * 2 * np.pi cosval = np.cos(rotation_angle) sinval = np.sin(rotation_angle) rotation_matrix = np.array( [[cosval, sinval, 0], [-sinval, cosval, 0], [0, 0, 1]] ) shape_pc = batch_data[k, ...] rotated_data[k, ...] = np.dot( shape_pc.reshape((-1, 3)), rotation_matrix ) return rotated_data def rotate_point_cloud_with_normal(batch_xyz_normal): """Randomly rotate XYZ, normal point cloud. Input: batch_xyz_normal: B,N,6, first three channels are XYZ, last 3 all normal Output: B,N,6, rotated XYZ, normal point cloud """ for k in range(batch_xyz_normal.shape[0]): rotation_angle = np.random.uniform() * 2 * np.pi cosval = np.cos(rotation_angle) sinval = np.sin(rotation_angle) rotation_matrix = np.array( [[cosval, 0, sinval], [0, 1, 0], [-sinval, 0, cosval]] ) shape_pc = batch_xyz_normal[k, :, 0:3] shape_normal = batch_xyz_normal[k, :, 3:6] batch_xyz_normal[k, :, 0:3] = np.dot( shape_pc.reshape((-1, 3)), rotation_matrix ) batch_xyz_normal[k, :, 3:6] = np.dot( shape_normal.reshape((-1, 3)), rotation_matrix ) return batch_xyz_normal def rotate_perturbation_point_cloud_with_normal( batch_data, angle_sigma=0.06, angle_clip=0.18 ): """Randomly perturb the point clouds by small rotations Input: BxNx6 array, original batch of point clouds and point normals Return: BxNx3 array, rotated batch of point clouds """ rotated_data = np.zeros(batch_data.shape, dtype=np.float32) for k in range(batch_data.shape[0]): angles = np.clip( angle_sigma * np.random.randn(3), -angle_clip, angle_clip ) Rx = np.array( [ [1, 0, 0], [0, np.cos(angles[0]), -np.sin(angles[0])], [0, np.sin(angles[0]), np.cos(angles[0])], ] ) Ry = np.array( [ [np.cos(angles[1]), 0, np.sin(angles[1])], [0, 1, 0], [-np.sin(angles[1]), 0, np.cos(angles[1])], ] ) Rz = np.array( [ [np.cos(angles[2]), -np.sin(angles[2]), 0], [np.sin(angles[2]), np.cos(angles[2]), 0], [0, 0, 1], ] ) R = np.dot(Rz, np.dot(Ry, Rx)) shape_pc = batch_data[k, :, 0:3] shape_normal = batch_data[k, :, 3:6] rotated_data[k, :, 0:3] = np.dot(shape_pc.reshape((-1, 3)), R) rotated_data[k, :, 3:6] = np.dot(shape_normal.reshape((-1, 3)), R) return rotated_data def rotate_point_cloud_by_angle(batch_data, rotation_angle): """Rotate the point cloud along up direction with certain angle. Input: BxNx3 array, original batch of point clouds Return: BxNx3 array, rotated batch of point clouds """ rotated_data = np.zeros(batch_data.shape, dtype=np.float32) for k in range(batch_data.shape[0]): # rotation_angle = np.random.uniform() * 2 * np.pi cosval = np.cos(rotation_angle) sinval = np.sin(rotation_angle) rotation_matrix = np.array( [[cosval, 0, sinval], [0, 1, 0], [-sinval, 0, cosval]] ) shape_pc = batch_data[k, :, 0:3] rotated_data[k, :, 0:3] = np.dot( shape_pc.reshape((-1, 3)), rotation_matrix ) return rotated_data def rotate_point_cloud_by_angle_with_normal(batch_data, rotation_angle): """Rotate the point cloud along up direction with certain angle. Input: BxNx6 array, original batch of point clouds with normal scalar, angle of rotation Return: BxNx6 array, rotated batch of point clouds iwth normal """ rotated_data = np.zeros(batch_data.shape, dtype=np.float32) for k in range(batch_data.shape[0]): # rotation_angle = np.random.uniform() * 2 * np.pi cosval = np.cos(rotation_angle) sinval = np.sin(rotation_angle) rotation_matrix = np.array( [[cosval, 0, sinval], [0, 1, 0], [-sinval, 0, cosval]] ) shape_pc = batch_data[k, :, 0:3] shape_normal = batch_data[k, :, 3:6] rotated_data[k, :, 0:3] = np.dot( shape_pc.reshape((-1, 3)), rotation_matrix ) rotated_data[k, :, 3:6] = np.dot( shape_normal.reshape((-1, 3)), rotation_matrix ) return rotated_data def rotate_perturbation_point_cloud( batch_data, angle_sigma=0.06, angle_clip=0.18 ): """Randomly perturb the point clouds by small rotations Input: BxNx3 array, original batch of point clouds Return: BxNx3 array, rotated batch of point clouds """ rotated_data = np.zeros(batch_data.shape, dtype=np.float32) for k in range(batch_data.shape[0]): angles = np.clip( angle_sigma * np.random.randn(3), -angle_clip, angle_clip ) Rx = np.array( [ [1, 0, 0], [0, np.cos(angles[0]), -np.sin(angles[0])], [0, np.sin(angles[0]), np.cos(angles[0])], ] ) Ry = np.array( [ [np.cos(angles[1]), 0, np.sin(angles[1])], [0, 1, 0], [-np.sin(angles[1]), 0, np.cos(angles[1])], ] ) Rz = np.array( [ [np.cos(angles[2]), -np.sin(angles[2]), 0], [np.sin(angles[2]), np.cos(angles[2]), 0], [0, 0, 1], ] ) R = np.dot(Rz, np.dot(Ry, Rx)) shape_pc = batch_data[k, ...] rotated_data[k, ...] = np.dot(shape_pc.reshape((-1, 3)), R) return rotated_data def jitter_point_cloud(batch_data, sigma=0.01, clip=0.05): """Randomly jitter points. jittering is per point. Input: BxNx3 array, original batch of point clouds Return: BxNx3 array, jittered batch of point clouds """ B, N, C = batch_data.shape assert clip > 0 jittered_data = np.clip(sigma * np.random.randn(B, N, C), -1 * clip, clip) jittered_data += batch_data return jittered_data def shift_point_cloud(batch_data, shift_range=0.1): """Randomly shift point cloud. Shift is per point cloud. Input: BxNx3 array, original batch of point clouds Return: BxNx3 array, shifted batch of point clouds """ B, N, C = batch_data.shape shifts = np.random.uniform(-shift_range, shift_range, (B, 3)) for batch_index in range(B): batch_data[batch_index, :, :] += shifts[batch_index, :] return batch_data def random_scale_point_cloud(batch_data, scale_low=0.8, scale_high=1.25): """Randomly scale the point cloud. Scale is per point cloud. Input: BxNx3 array, original batch of point clouds Return: BxNx3 array, scaled batch of point clouds """ B, N, C = batch_data.shape scales = np.random.uniform(scale_low, scale_high, B) for batch_index in range(B): batch_data[batch_index, :, :] *= scales[batch_index] return batch_data def random_point_dropout(batch_pc, max_dropout_ratio=0.875): """batch_pc: BxNx3""" for b in range(batch_pc.shape[0]): dropout_ratio = np.random.random() * max_dropout_ratio # 0~0.875 drop_idx = np.where( np.random.random((batch_pc.shape[1])) <= dropout_ratio )[0] if len(drop_idx) > 0: dropout_ratio = ( np.random.random() * max_dropout_ratio ) # 0~0.875 # not need batch_pc[b, drop_idx, :] = batch_pc[ b, 0, : ] # set to the first point return batch_pc