Pyrr

0.10.3 verified Fri May 01 auth: no python

Pyrr provides 3D mathematical functions (matrices, quaternions, vectors, eulers) using NumPy arrays. Current version: 0.10.3. Infrequent releases, last stable in 2022.

pip install pyrr

Common errors

error ImportError: cannot import name 'matrix44' from 'pyrr' ↓

cause After 0.9.0, some submodules like 'pyrr.matrix44' are still present but functions have been renamed. However, the import itself should work if the module exists. This error may occur if the package is not installed correctly or if there's a naming confusion.

fix

Run pip install --upgrade pyrr. Then use from pyrr.matrix44 import create_from_translation.

error ValueError: The truth value of an array with more than one element is ambiguous. ↓

cause Using a Pyrr object (e.g., Vector3) in a boolean context (if vec: ...). Pyrr objects inherit NumPy array behavior and cannot be used as booleans directly.

fix

Use if vec.any(): or if vec.all(): depending on intent.

error AttributeError: 'Matrix44' object has no attribute 'create_look_at' ↓

cause Using old API. `create_look_at` is a module-level function, not a method on Matrix44. Also, it was renamed in 0.9.0.

fix

Use from pyrr.matrix44 import create_look_at and call create_look_at(eye, target, up).

Warnings

breaking In version 0.8.0, the parameter order for `euler.create_from_euler` changed from (pitch, roll, yaw) to (roll, pitch, yaw). Code using the old order will produce incorrect rotations. ↓

fix Update calls: `euler.create_from_euler(roll, pitch, yaw, ...)` instead of `(pitch, roll, yaw, ...)`.

breaking In version 0.9.0, many matrix functions with '_matrix' in the name were deprecated. For example, `matrix44.create_look_at_matrix` is deprecated in favor of `matrix44.create_look_at`. ↓

fix Use the new function names without '_matrix'. Check the deprecation warnings in your code.

gotcha Pyrr internally uses NumPy arrays. Directly mutating the underlying array can cause unexpected behavior. Always use the provided methods or create new objects. ↓

fix Avoid modifying `obj.flat` or `.data`; use obj.copy() or constructors.

Imports

Matrix44
```
from pyrr import Matrix44
```
Correct import path
Quaternion
```
from pyrr import Quaternion
```
Vector3
```
from pyrr import Vector3
```
matrix44
wrong
```
from pyrr import matrix44
```
correct
```
from pyrr.matrix44 import create_from_translation
```
Submodule functions must be imported explicitly; top-level only has classes.
euler
```
from pyrr import euler
```

Quickstart

Creates a translation matrix, a rotation quaternion, and applies it to a vector.

import numpy as np
from pyrr import Matrix44, Vector3, Quaternion

# Create a translation matrix
trans = Matrix44.from_translation([1, 2, 3])
print(trans)

# Create a rotation quaternion (90 degrees around Y axis)
rot = Quaternion.from_axis_rotation([0.0, 1.0, 0.0], np.pi/2)
print(rot)

# Apply rotation to a vector
vec = Vector3([1, 0, 0])
transformed = rot * vec
print(transformed)