voxcity.simulator_gpu.visibility.SurfaceViewFactorCalculator
============================================================

.. py:class:: voxcity.simulator_gpu.visibility.SurfaceViewFactorCalculator(domain, n_azimuth: int = 120, n_elevation: int = 20, ray_sampling: str = 'grid', n_rays: int = None, precompute_directions: bool = True)

   GPU-accelerated Surface View Factor calculator.

   Computes view factors for building surface faces by tracing rays from
   face centers through the voxel domain.

   This emulates voxcity.simulator.visibility.view.get_surface_view_factor
   using Taichi GPU acceleration.


   .. py:attribute:: domain


   .. py:attribute:: nx


   .. py:attribute:: ny


   .. py:attribute:: nz


   .. py:attribute:: dx


   .. py:attribute:: dy


   .. py:attribute:: dz


   .. py:attribute:: meshsize


   .. py:attribute:: n_azimuth
      :value: 120



   .. py:attribute:: n_elevation
      :value: 20



   .. py:attribute:: ray_sampling
      :value: 'grid'



   .. py:attribute:: n_rays


   .. py:method:: compute_surface_view_factor(face_centers: numpy.ndarray, face_normals: numpy.ndarray, voxel_data: numpy.ndarray = None, target_values: Tuple[int, Ellipsis] = (0, ), inclusion_mode: bool = False, tree_k: float = 0.6, tree_lad: float = 1.0, boundary_epsilon: float = None, workspace=None) -> numpy.ndarray

      Compute view factors for building surface faces.

      :param face_centers: Array of face center positions (n_faces, 3) in world coords
      :param face_normals: Array of face normal vectors (n_faces, 3)
      :param voxel_data: 3D voxel class array
      :param target_values: Target voxel values for visibility
      :param inclusion_mode: If True, count hits on targets; if False, count unblocked rays
      :param tree_k: Tree extinction coefficient
      :param tree_lad: Leaf area density
      :param boundary_epsilon: Epsilon for boundary detection
      :param workspace: Optional pre-allocated SurfaceViewWorkspace whose Taichi fields are
                        reused instead of allocating new ones on every call.

      :returns: 1D array of view factor values for each face