renderer.set_shader_program(&distant_shprog, &shdata);
renderer.set_texture("transmittance_lookup", &transmittance_lookup.get_target_texture(0), &sampler);
fullscreen_mesh.draw(renderer);
renderer.set_shader_program(&distant_shprog, &shdata);
renderer.set_texture("transmittance_lookup", &transmittance_lookup.get_target_texture(0), &sampler);
fullscreen_mesh.draw(renderer);