inner_product ( u,  v )

oppositely_directed_line ( line )

clip_segment_with_planes (
        xyz_1,
        xyz_2,
        planes,
        )

Plane normals point towards unclipped half-space.

transform_plane ( plane,  transform )

The transform need not be orthogonal.

box_line_intercepts ( line,  xyz_region )

line_perpendicular_to_screen (
        window_x,
        window_y,
        transform,
        )

Returned line is transformed from screen coordinates using the given transform

box_entry_point ( line,  xyz_region )

Place where directed line enters box, or None if no intersection.

per_model_clip_planes ( clip_plane_model )

Returned planes are in screen coordinates. Normal points toward unclipped half-space.

clip_plane_points ( window_x,  window_y )

Find points on near and far clip planes under the specified window position. The returned points are in eye coordinates.

clip_planes ( transform,  clip_plane_model=None )

Returned planes are transformed from screen coordinates using the given transform. Plane normals point toward unclipped half-space.

box_intercepts (
        window_x,
        window_y,
        box_to_screen_transform,
        box,
        clip_plane_model=None,
        )

Find points under the specified window position intersecting surface of a box. The box is specified as (xyz_min, xyz_max). The returned points are in box coordinates. The segment inside the box is clipped by near and far clip planes. It is also clipped by per-model clip planes if the clip_plane_model is provided.