artist.nurbs.utils
==================

.. py:module:: artist.nurbs.utils


Functions
---------

.. autoapisummary::

   artist.nurbs.utils.create_nurbs_evaluation_grid
   artist.nurbs.utils.create_planar_nurbs_control_points


Module Contents
---------------

.. py:function:: create_nurbs_evaluation_grid(number_of_evaluation_points: torch.Tensor, epsilon: float = 1e-07, device: torch.device | None = None) -> torch.Tensor

   Create a grid of evaluation points for a NURBS surface.

   Parameters
   ----------
   number_of_evaluation_points : torch.Tensor
       The number of nurbs evaluation points in east and north direction.
       Shape is ``[2]``.
   epsilon : float
       Offset for the NURBS evaluation points (default is 1e-7).
       NURBS are defined in the interval of [0, 1] but have numerical instabilities at their endpoints.
       Therefore, the evaluation points need a small offset from the endpoints.
   device : torch.device | None
       The device on which to perform computations or load tensors and models (default is None).
       If None, ``ARTIST`` will automatically select the most appropriate
       device (CUDA or CPU) based on availability and OS.

   Returns
   -------
   torch.Tensor
       The evaluation points.
       Shape is ``[number_of_evaluation_points_e * number_of_evaluation_points_n, 2]``.


.. py:function:: create_planar_nurbs_control_points(number_of_control_points: torch.Tensor, canting: torch.Tensor, device: torch.device | None = None) -> torch.Tensor

   Create planar NURBS control points for each facet.

   The generated control points form a flat, equidistant grid.
   The grid extent is derived from the norm of the canting vectors, which encode the
   dimensions of the facets.

   Parameters
   ----------
   number_of_control_points : torch.Tensor
       The number of NURBS control points.
       Shape is ``[2]``.
   canting : torch.Tensor
       The canting vector for each facet.
       Shape is ``[number_of_facets, 2, 4]``.
   device : torch.device | None
       The device on which to perform computations or load tensors and models (default is None).
       If None, ``ARTIST`` will automatically select the most appropriate
       device (CUDA or CPU) based on availability and OS.

   Returns
   -------
   torch.Tensor
       Planar control point grids for each facet.
       Shape is ``[number_of_facets, number_of_control_points_u_direction, number_of_control_points_v_direction, 3]``.