GIRAFFE feature and sigma fields

generator_feature_and_sigma.py

# adapted from https://github.com/autonomousvision/giraffe (MIT License)
n_iter = n_boxes if not_render_background else n_boxes + 1
# ...
for i in range(n_iter):
    if i < n_boxes:  # Object
        p_i, r_i = self.get_evaluation_points(pixels_world,
            camera_world, di, transformations, i)
        z_shape_i, z_app_i = z_shape_obj[:, i], z_app_obj[:, i]
        feat_i, sigma_i = self.decoder(p_i, r_i, z_shape_i, z_app_i)
        # ...
    else:  # Background
        p_bg, r_bg = self.get_evaluation_points_bg(pixels_world,
            camera_world, di, bg_rotation)
        feat_i, sigma_i = self.background_generator(
            p_bg, r_bg, z_shape_bg, z_app_bg)
        # ...
    feat.append(feat_i)
    sigma.append(sigma_i)
# ...