Function generate_interpolated_path

utils/pose_utils.py:418–569

Creates a smooth spline path between input keyframe camera poses. Spline is calculated with poses in format (position, lookat-point, up-point). Args: poses: (n, 3, 4) array of input pose keyframes. n_interp: returned path will have n_interp * (n - 1) total poses. spline_degree: poly

(
    views,
    n_interp,
    spline_degree = 5,
    smoothness = 0.03,
    rot_weight = 0.1,
    lock_up = False,
    fixed_up_vector = None,
    lookahead_i = None,
    frames_per_colmap = None,
    const_speed = False,
    n_buffer = None,
    periodic = False,
    n_interp_as_total = False,
)

def generate_interpolated_path(
    views,
    n_interp,
    spline_degree = 5,
    smoothness = 0.03,
    rot_weight = 0.1,
    lock_up = False,
    fixed_up_vector = None,
    lookahead_i = None,
    frames_per_colmap = None,
    const_speed = False,
    n_buffer = None,
    periodic = False,
    n_interp_as_total = False,
):
  """Creates a smooth spline path between input keyframe camera poses.

  Spline is calculated with poses in format (position, lookat-point, up-point).
  Args:
    poses: (n, 3, 4) array of input pose keyframes.
    n_interp: returned path will have n_interp * (n - 1) total poses.
    spline_degree: polynomial degree of B-spline.
    smoothness: parameter for spline smoothing, 0 forces exact interpolation.
    rot_weight: relative weighting of rotation/translation in spline solve.
    lock_up: if True, forced to use given Up and allow Lookat to vary.
    fixed_up_vector: replace the interpolated `up` with a fixed vector.
    lookahead_i: force the look direction to look at the pose `i` frames ahead.
    frames_per_colmap: conversion factor for the desired average velocity.
    const_speed: renormalize spline to have constant delta between each pose.
    n_buffer: Number of buffer frames to insert at the start and end of the
      path. Helps keep the ends of a spline path straight.
    periodic: make the spline path periodic (perfect loop).
    n_interp_as_total: use n_interp as total number of poses in path rather than
      the number of poses to interpolate between each input.

  Returns:
    Array of new camera poses with shape (n_interp * (n - 1), 3, 4), or
    (n_interp, 3, 4) if n_interp_as_total is set.
  """
  poses = []
  for view in views:
    tmp_view = np.eye(4)
    tmp_view[:3] = np.concatenate([view.R.T, view.T[:, None]], 1)
    tmp_view = np.linalg.inv(tmp_view)
    tmp_view[:, 1:3] *= -1
    poses.append(tmp_view)
  poses = np.stack(poses, 0)

  def poses_to_points(poses, dist):
    """Converts from pose matrices to (position, lookat, up) format."""
    pos = poses[:, :3, -1]
    lookat = poses[:, :3, -1] - dist * poses[:, :3, 2]
    up = poses[:, :3, -1] + dist * poses[:, :3, 1]
    return np.stack([pos, lookat, up], 1)

  def points_to_poses(points):
    """Converts from (position, lookat, up) format to pose matrices."""
    poses = []