code: def _trefoil_knot(t: torch.Tensor, z_scale: float = 0.5):
      x = t.sin() + 2 * (2 * t).sin()
      y = t.cos() - 2 * (2 * t).cos()
      z = -(3 * t).sin() * z_scale
      return torch.stack((x, y, z), dim=-1)
  
file_path: pytorch3d/pytorch3d/implicitron/tools/eval_video_trajectory.py
imports: import logging
  import math
  from typing import Optional, Tuple
  import torch
  from pytorch3d.implicitron.tools import utils
  from pytorch3d.implicitron.tools.circle_fitting import fit_circle_in_3d
  from pytorch3d.renderer import look_at_view_transform, PerspectiveCameras
  from pytorch3d.transforms import Scale
label_desc: Use image node_id 7 for calling a global function with example usage: _trefoil_knot(t, z_scale) and returns: torch