Ray

Rays are stand-ins for lightrays heading from the camera through the scene.

class padvinder.ray.Ray(position=(0, 0, 0), direction=(1, 0, 0))

Bases: object

A ray consists of a starting position and a direction. Both are specified as vectors.

The starting position is a point in the scene, the ray begins in. The direction is where the ray is heading in and is always normalized.

Parameters:

• position (numpy.ndarray_like) – an array of three dimension
• direction (numpy.ndarray_like) – Direction must have the same number of dimension as position. The direction vector will be stored normalized to a length of one and can not initially have lenght zero.

Raises:

• ValueError – Raises a ValueError if the input contains NaNs or Infs.
• ZeroDivisionError – Raises a ZeroDivisionError if the direction vector has length zero

Examples

>>> Ray((0, 0, 0), (1, 0, 0))
Ray([0.0, 0.0, 0.0], [1.0, 0.0, 0.0])
>>> Ray((3.0, 2.3, -5.1), (-10.0, 34.0, -2.0))
Ray([3.0, 2.3, -5.1], [-0.28171808,  0.95784149, -0.05634362])

position

Return the ray’s position.

direction

Return the ray’s normalized direction.

point(distance)

Returns a point lying t-units from the origin on the ray.

Parameters:distance (float) – The number of units along the ray to get the point of Returns:point on ray – where the point is calculated as ray_origin + distance*ray_direction Return type:numpy.ndarray_like

Examples

>>> Ray((0, 0, 0), (1, 0, 0)).point(10)
[10.0, 0.0, 0.0]