Vector functions

Common Vector Operations

Common Vector manipulation functions.

pyrr.vector.dot(*args, **kwargs)

Calculates the dot product of two vectors.

Parameters:
  • v1 (numpy.array) – an Nd array with the final dimension being size 3. (a vector)
  • v2 (numpy.array) – an Nd array with the final dimension being size 3 (a vector)
Return type:

If a 1d array was passed, it will be a scalar. Otherwise the result will be an array of scalars with shape vec.ndim with the last dimension being size 1.
pyrr.vector.interpolate(*args, **kwargs)

Interpolates between 2 arrays of vectors (shape = N,3) by the specified delta (0.0 <= delta <= 1.0).

Parameters:
  • v1 (numpy.array) – an Nd array with the final dimension being size 3. (a vector)
  • v2 (numpy.array) – an Nd array with the final dimension being size 3. (a vector)
  • delta (float) – The interpolation percentage to apply, where 0.0 <= delta <= 1.0. When delta is 0.0, the result will be v1. When delta is 1.0, the result will be v2. Values inbetween will be an interpolation.
Return type:

A numpy.array with shape v1.shape.
pyrr.vector.length(*args, **kwargs)

Returns the length of an Nd list of vectors or a single vector.

Parameters:vec (numpy.array) –

an Nd array with the final dimension being size 3 (a vector).

Single vector:

numpy.array([ x, y, z ])

Nd array:

numpy.array([
    [x1, y1, z1],
    [x2, y2, z2]
]).
Return type:If a 1d array was passed, it will be a scalar. Otherwise the result will be an array of scalars with shape vec.ndim with the last dimension being size 1.
pyrr.vector.normalise(*args, **kwargs)

normalizes an Nd list of vectors or a single vector to unit length.

The vector is not changed in place.

For zero-length vectors, the result will be np.nan.

Parameters:vec (numpy.array) –

an Nd array with the final dimension being vectors

numpy.array([ x, y, z ])

Or an NxM array:

numpy.array([
    [x1, y1, z1],
    [x2, y2, z2]
]).
Return type:A numpy.array the normalized value
pyrr.vector.normalize(*args, **kwargs)

normalizes an Nd list of vectors or a single vector to unit length.

The vector is not changed in place.

For zero-length vectors, the result will be np.nan.

Parameters:vec (numpy.array) –

an Nd array with the final dimension being vectors

numpy.array([ x, y, z ])

Or an NxM array:

numpy.array([
    [x1, y1, z1],
    [x2, y2, z2]
]).
Return type:A numpy.array the normalized value
pyrr.vector.set_length(*args, **kwargs)

Resizes an Nd list of vectors or a single vector to ‘length’.

The vector is not changed in place.

Parameters:vec (numpy.array) –

an Nd array with the final dimension being size 3 (a vector).

Single vector::
numpy.array([ x, y, z ])
Nd array::
numpy.array([
[x1, y1, z1], [x2, y2, z2]

]).
Return type:A numpy.array of shape vec.shape.
pyrr.vector.squared_length(*args, **kwargs)

Calculates the squared length of a vector.

Useful when trying to avoid the performance penalty of a square root operation.

Parameters:vec (numpy.array) – An Nd numpy.array.
Return type:If one vector is supplied, the result with be a scalar. Otherwise the result will be an array of scalars with shape vec.ndim with the last dimension being size 1.

Vector3

Provides functions for creating and manipulating 3D vectors.

pyrr.vector3.create(x=0.0, y=0.0, z=0.0, dtype=None)
pyrr.vector3.create_from_matrix44_translation(*args, **kwargs)
pyrr.vector3.create_from_vector4(*args, **kwargs)

Returns a vector3 and the W component as a tuple.

pyrr.vector3.create_unit_length_x(dtype=None)
pyrr.vector3.create_unit_length_y(dtype=None)
pyrr.vector3.create_unit_length_z(dtype=None)
pyrr.vector3.cross(v1, v2)

Calculates the cross-product of two vectors.

Parameters:
  • v1 (numpy.array) – an Nd array with the final dimension being size 3. (a vector)
  • v2 (numpy.array) – an Nd array with the final dimension being size 3. (a vector)
Return type:

A np.array with shape v1.shape.
pyrr.vector3.generate_normals(v1, v2, v3, normalize_result=True)

Generates a normal vector for 3 vertices.

The result is a normalized vector.

It is assumed the ordering is counter-clockwise starting at v1, v2 then v3:

v1      v3
  \    /
    v2

The vertices are Nd arrays and may be 1d or Nd. As long as the final axis is of size 3.

For 1d arrays::
>>> v1 = numpy.array( [ 1.0, 0.0, 0.0 ] )
>>> v2 = numpy.array( [ 0.0, 0.0, 0.0 ] )
>>> v3 = numpy.array( [ 0.0, 1.0, 0.0 ] )
>>> vector.generate_normals( v1, v2, v3 )
array([ 0.,  0., -1.])
For Nd arrays::
>>> v1 = numpy.array( [ [ 1.0, 0.0, 0.0 ], [ 1.0, 0.0, 0.0 ] ] )
>>> v2 = numpy.array( [ [ 0.0, 0.0, 0.0 ], [ 0.0, 0.0, 0.0 ] ] )
>>> v3 = numpy.array( [ [ 0.0, 1.0, 0.0 ], [ 0.0, 1.0, 0.0 ] ] )
>>> vector.generate_normals( v1, v2, v3 )
array([[ 0.,  0., -1.],
       [ 0.,  0., -1.]])
Parameters:
  • v1 (numpy.array) – an Nd array with the final dimension being size 3. (a vector)
  • v2 (numpy.array) – an Nd array with the final dimension being size 3. (a vector)
  • v3 (numpy.array) – an Nd array with the final dimension being size 3. (a vector)
  • normalize_result (boolean) – Specifies if the result should be normalized before being returned.
pyrr.vector3.generate_vertex_normals(vertices, index, normalize_result=True)

Generates a normal vector for each vertex.

The result is a normalized vector.

The index array should list the faces by indexing into the vertices array. It is assumed the ordering in index is counter-clockwise.

The vertices and index arrays are Nd arrays and must be 2d, where the final axis is of size 3.

An example::
>>> vertices = numpy.array( [ [ 1.0, 0.0, 0.0 ], [ 0.0, 0.0, 0.0 ], [ 0.0, 1.0, 0.0 ] ] )
>>> index = numpy.array( [ [ 0, 2, 1 ] ] )
>>> vector.generate_vertex_normals( vertices, index )
array([[ 0.,  0., 1.], [ 0.,  0., 1.], [ 0.,  0., 1.]])
Parameters:
  • vertices (numpy.array) – an 2d array with the final dimension being size 3. (a vector)
  • index (numpy.array) – an Nd array with the final dimension being size 3. (a vector)
  • normalize_result (boolean) – Specifies if the result should be normalized before being returned.
class pyrr.vector3.index
x = 0
y = 1
z = 2
class pyrr.vector3.unit
x = array([1., 0., 0.])
y = array([0., 1., 0.])
z = array([0., 0., 1.])

Vector4

Provides functions for creating and manipulating 4D vectors.

pyrr.vector4.create(x=0.0, y=0.0, z=0.0, w=0.0, dtype=None)
pyrr.vector4.create_from_matrix44_translation(*args, **kwargs)
pyrr.vector4.create_from_vector3(*args, **kwargs)
pyrr.vector4.create_unit_length_w(dtype=None)
pyrr.vector4.create_unit_length_x(dtype=None)
pyrr.vector4.create_unit_length_y(dtype=None)
pyrr.vector4.create_unit_length_z(dtype=None)
class pyrr.vector4.index
w = 3
x = 0
y = 1
z = 2
class pyrr.vector4.unit
x = array([1., 0., 0., 0.])
y = array([0., 1., 0., 0.])
z = array([0., 0., 1., 0.])