def backward()

in pytorch3d/renderer/points/pulsar/renderer.py [0:0]
103 lines of code
15 McCabe index (conditional complexity)

    def backward(ctx, grad_im, *args):
        global GAMMA_WARNING_EMITTED
        (
            vert_pos,
            vert_col,
            vert_rad,
            cam_pos,
            pixel_0_0_center,
            pixel_vec_x,
            pixel_vec_y,
            focal_length,
            principal_point_offsets,
            bg_col,
            opacity,
            image,
            info,
        ) = ctx.saved_tensors
        if (
            (
                ctx.needs_input_grad[0]
                or ctx.needs_input_grad[2]
                or ctx.needs_input_grad[3]
                or ctx.needs_input_grad[4]
                or ctx.needs_input_grad[5]
                or ctx.needs_input_grad[6]
                or ctx.needs_input_grad[7]
            )
            and ctx.gamma < 1e-3
            and not GAMMA_WARNING_EMITTED
        ):
            warnings.warn(
                "Optimizing for non-color parameters and having a gamma value < 1E-3! "
                "This is probably not going to produce usable gradients."
            )
            GAMMA_WARNING_EMITTED = True
        if ctx.mode == 0:
            (
                grad_pos,
                grad_col,
                grad_rad,
                grad_cam_pos,
                grad_pixel_0_0_center,
                grad_pixel_vec_x,
                grad_pixel_vec_y,
                grad_opacity,
            ) = ctx.native_renderer.backward(
                grad_im,
                image,
                info,
                vert_pos,
                vert_col,
                vert_rad,
                cam_pos,
                pixel_0_0_center,
                pixel_vec_x,
                pixel_vec_y,
                focal_length,
                principal_point_offsets,
                ctx.gamma,
                ctx.max_depth,
                ctx.min_depth,
                bg_col,
                opacity,
                ctx.percent_allowed_difference,
                ctx.max_n_hits,
                ctx.mode,
                ctx.needs_input_grad[0],
                ctx.needs_input_grad[1],
                ctx.needs_input_grad[2],
                ctx.needs_input_grad[3]
                or ctx.needs_input_grad[4]
                or ctx.needs_input_grad[5]
                or ctx.needs_input_grad[6]
                or ctx.needs_input_grad[7],
                ctx.needs_input_grad[14],
                None,  # No debug information provided.
            )
        else:
            raise ValueError(
                "Performing a backward pass for a "
                "rendering with `mode != 0`! This is not possible."
            )
        return (
            grad_pos,
            grad_col,
            grad_rad,
            grad_cam_pos,
            grad_pixel_0_0_center,
            grad_pixel_vec_x,
            grad_pixel_vec_y,
            None,  # focal_length
            None,  # principal_point_offsets
            None,  # gamma
            None,  # max_depth
            None,  # native_renderer
            None,  # min_depth
            None,  # bg_col
            grad_opacity,
            None,  # percent_allowed_difference
            None,  # max_n_hits
            None,  # mode
            None,  # return_forward_info
        )