kaolin.render.camera

API

kaolin.render.camera.generate_perspective_projection(fovyangle, ratio=1.0, dtype=torch.float32)

Generate perspective projection matrix for a given camera fovy angle.

Parameters:
  • fovyangle (float) – field of view angle of y axis, \(tan(\frac{fovy}{2}) = \frac{y}{f}\).
  • ratio (float) – aspect ratio \((\frac{width}{height})\). Default: 1.0.
Returns:

camera projection matrix, of shape \((3, 1)\).
Return type:

(torch.FloatTensor)
kaolin.render.camera.generate_rotate_translate_matrices(camera_position, look_at, camera_up_direction)

generate rotation and translation matrix for given camera parameters. Formula is \(\text{P_cam} = \text{mtx} * \text{P_world} + \text{shift}\)

Parameters:
  • camera_position (torch.FloatTensor) – camera positions of shape \((\text{batch_size}, 3)\), it means where your cameras are
  • look_at (torch.FloatTensor) – where the camera is watching, of shape \((\text{batch_size}, 3)\),
  • camera_up_direction (torch.FloatTensor) – camera up directions of shape \((\text{batch_size}, 3)\), it means what are your camera up directions, generally [0, 1, 0]
Returns:

the camera rotation matrix of shape \((\text{batch_size}, 3, 3)\) and the camera transformation matrix of shape \((\text{batch_size}, 3)\)
Return type:

(torch.FloatTensor, torch.FloatTensor)
kaolin.render.camera.perspective_camera(points, camera_proj)

Projects 3D points on 2D images in perspective projection mode.

Parameters:
  • points (torch.FloatTensor) – 3D points in camera coordinate, of shape \((\text{batch_size}, \text{num_points}, 3)\).
  • camera_proj (torch.FloatTensor) – projection matrix of shape \((3, 1)\).
Returns:

2D points on image plane of shape \((\text{batch_size}, \text{num_points}, 2)\).
Return type:

(torch.FloatTensor)
kaolin.render.camera.rotate_translate_points(points, camera_rot, camera_trans)

rotate and translate 3D points on based on rotation matrix and transformation matrix. Formula is \(\text{P_new} = R * (\text{P_old} - T)\)

Parameters:
  • points (torch.FloatTensor) – 3D points, of shape \((\text{batch_size}, \text{num_points}, 3)\).
  • camera_rot (torch.FloatTensor) – rotation matrix, of shape \((\text{batch_size}, 3, 3)\).
  • camera_trans (torch.FloatTensor) – translation matrix, of shape \((\text{batch_size}, 3, 1)\).
Returns:

3D points in new rotation, of same shape than points.
Return type:

(torch.FloatTensor)