Module: Gsplat::Backend::RubyAccumulate

Defined in:
lib/gsplat/backend/ruby/accumulate.rb

Overview

Brute-force Numo alpha compositor used as a rasterization reference.

Constant Summary collapse

ALPHA_CLAMP = 
0.999
ALPHA_SKIP = 
1.0 / 255.0
TRANSMITTANCE_STOP = 
1e-4

Class Method Summary collapse

Class Method Details

.forward(means2d, conics, opacities, colors, backgrounds, width, height) ⇒ Object

rubocop:disable Metrics/AbcSize, Metrics/ParameterLists



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# File 'lib/gsplat/backend/ruby/accumulate.rb', line 14

def forward(means2d, conics, opacities, colors, backgrounds, width, height)
  # rubocop:enable Metrics/ParameterLists
  inputs = validate_inputs(means2d, conics, opacities, colors, backgrounds, width, height)
  means2d, conics, opacities, colors, backgrounds = inputs
  camera_count, gaussian_count = means2d.shape[0...2]
  channel_count = colors.shape[-1]
  pixel_count = width * height
  pixels_x, pixels_y = pixel_coordinates(means2d.class, width, height)
  render_colors = means2d.class.zeros(camera_count, pixel_count, channel_count)
  render_alphas = means2d.class.zeros(camera_count, pixel_count)
  last_ids = Numo::Int32.zeros(camera_count, pixel_count)
  camera_count.times do |camera_index|
    composited, transmittance, camera_last_ids = composite_camera(
      means2d[camera_index, true, true],
      conics[camera_index, true, true],
      opacities[camera_index, true],
      colors[camera_index, true, true],
      pixels_x,
      pixels_y,
      gaussian_count
    )
    if backgrounds
      composited += transmittance.reshape(pixel_count, 1) *
                    backgrounds[camera_index, true].reshape(1, channel_count)
    end
    render_colors[camera_index, true, true] = composited
    render_alphas[camera_index, true] = 1 - transmittance
    last_ids[camera_index, true] = camera_last_ids + (camera_index * gaussian_count)
  end
  [
    render_colors.reshape(camera_count, height, width, channel_count),
    render_alphas.reshape(camera_count, height, width, 1),
    last_ids.reshape(camera_count, height, width)
  ]
end