voxcity.simulator_gpu.solar.svf.SVFCalculator
=============================================

.. py:class:: voxcity.simulator_gpu.solar.svf.SVFCalculator(domain, n_azimuth: int = 80, n_elevation: int = 40)

   GPU-accelerated Sky View Factor calculator.

   Computes SVF by tracing rays from each surface to the hemisphere.
   SVF = fraction of hemisphere visible from surface.


   .. py:attribute:: domain


   .. py:attribute:: nx


   .. py:attribute:: ny


   .. py:attribute:: nz


   .. py:attribute:: dx


   .. py:attribute:: dy


   .. py:attribute:: dz


   .. py:attribute:: n_azimuth
      :value: 80



   .. py:attribute:: n_elevation
      :value: 40



   .. py:attribute:: n_directions
      :value: 3200



   .. py:attribute:: max_dist


   .. py:attribute:: directions


   .. py:attribute:: solid_angles


   .. py:attribute:: total_solid_angle


   .. py:method:: compute_svf(surf_pos: ti.template(), surf_dir: ti.template(), is_solid: ti.template(), n_surf: taichi.i32, svf: ti.template())

      Compute Sky View Factor for all surfaces.

      Uses PALM's methodology (radiation_model_mod.f90):
      - For upward surfaces: vffrac_up = (cos(2*elev_low) - cos(2*elev_high)) / (2*n_azim)
      - For vertical surfaces: vffrac_vert = (sin(az2) - sin(az1)) * elev_terms / (2*pi)
        where az is measured relative to surface normal and elev_terms accounts for
        the elevation integration.

      :param surf_pos: Surface positions (n_surf, 3)
      :param surf_dir: Surface directions (n_surf,)
      :param is_solid: 3D field of solid cells
      :param n_surf: Number of surfaces
      :param svf: Output SVF values (n_surf,)



   .. py:method:: compute_svf_with_canopy(surf_pos: ti.template(), surf_dir: ti.template(), is_solid: ti.template(), lad: ti.template(), n_surf: taichi.i32, ext_coef: taichi.f32, svf: ti.template(), svf_urban: ti.template())

      Compute SVF including canopy absorption.

      Uses PALM's methodology (radiation_model_mod.f90):
      - For upward surfaces: vffrac_up = (cos(2*elev_low) - cos(2*elev_high)) / (2*n_azim)
      - For vertical surfaces: vffrac_vert = (sin(az2) - sin(az1)) * elev_terms / (2*pi)

      :param surf_pos: Surface positions
      :param surf_dir: Surface directions
      :param is_solid: 3D solid field
      :param lad: 3D Leaf Area Density field
      :param n_surf: Number of surfaces
      :param ext_coef: Extinction coefficient
      :param svf: Output SVF with canopy (n_surf,)
      :param svf_urban: Output SVF without canopy (n_surf,)