feat: matrix helper methods (#1806)

Co-authored-by: pyansys-ci-bot <[email protected]>
Co-authored-by: Roberto Pastor Muela <[email protected]>

Author: 3 people

doc/changelog.d/1806.added.md

@@ -0,0 +1 @@
+matrix helper methods

src/ansys/geometry/core/math/matrix.py

@@ -30,6 +30,7 @@
 from ansys.geometry.core.typing import Real, RealSequence
 
 if TYPE_CHECKING:
+    from ansys.geometry.core.math.frame import Frame
     from ansys.geometry.core.math.vector import Vector3D  # For type hints
 
 DEFAULT_MATRIX33 = np.identity(3)
@@ -308,3 +309,61 @@ def create_rotation(
             ]
         )
         return matrix
+
+    @classmethod
+    def create_matrix_from_rotation_about_axis(cls, axis: "Vector3D", angle: float) -> "Matrix44":
+        """
+        Create a matrix representing a rotation about a given axis.
+
+        Parameters
+        ----------
+        axis : Vector3D
+            The axis of rotation.
+        angle : float
+            The angle of rotation in radians.
+
+        Returns
+        -------
+        Matrix44
+            A 4x4 matrix representing the rotation.
+        """
+        axis_dir = axis.normalize()
+        x, y, z = axis_dir[0], axis_dir[1], axis_dir[2]
+
+        k = np.array([[0, -z, y], [z, 0, -x], [-y, x, 0]])
+
+        identity = np.eye(3)
+        cos_theta = np.cos(angle)
+        sin_theta = np.sin(angle)
+
+        # Rodrigues' rotation formula
+        rotation_3x3 = identity + sin_theta * k + (1 - cos_theta) * (k @ k)
+
+        # Convert to a 4x4 homogeneous matrix
+        rotation_matrix = np.eye(4)
+        rotation_matrix[:3, :3] = rotation_3x3
+
+        return cls(rotation_matrix)
+
+    @classmethod
+    def create_matrix_from_mapping(cls, frame: "Frame") -> "Matrix44":
+        """
+        Create a matrix representing the specified mapping.
+
+        Parameters
+        ----------
+        frame : Frame
+            The frame containing the origin and direction vectors.
+
+        Returns
+        -------
+        Matrix44
+            A 4x4 matrix representing the translation and rotation defined by the frame.
+        """
+        from ansys.geometry.core.math.vector import Vector3D
+
+        translation_matrix = Matrix44.create_translation(
+            Vector3D([frame.origin[0], frame.origin[1], frame.origin[2]])
+        )
+        rotation_matrix = Matrix44.create_rotation(frame.direction_x, frame.direction_y)
+        return translation_matrix * rotation_matrix

src/ansys/geometry/core/math/vector.py

@@ -32,6 +32,7 @@
 from ansys.geometry.core.math.point import Point2D, Point3D
 from ansys.geometry.core.misc.accuracy import Accuracy
 from ansys.geometry.core.misc.checks import check_ndarray_is_float_int
+from ansys.geometry.core.misc.measurements import Angle
 from ansys.geometry.core.misc.units import UNITS
 from ansys.geometry.core.typing import Real, RealSequence
 
@@ -163,6 +164,22 @@ def transform(self, matrix: "Matrix44") -> "Vector3D":
         result_vector = Vector3D(result_4x1[0:3])
         return result_vector
 
+    @check_input_types
+    def rotate_vector(self, vector: "Vector3D", angle: Real | Quantity | Angle) -> "Vector3D":
+        """Rotate a vector around a given axis by a specified angle."""
+        if self.is_zero:
+            raise Exception("Invalid vector operation: rotation axis cannot be zero.")
+
+        # Convert angle to Angle object and get its value in radians
+        angle = angle if isinstance(angle, Angle) else Angle(angle)
+        angle_m = angle.value.m_as(UNITS.radian)
+
+        axis = self.normalize()
+        parallel = axis * (vector.dot(axis))
+        perpendicular1 = vector - parallel
+        perpendicular2 = axis.cross(perpendicular1)
+        return parallel + perpendicular1 * np.cos(angle_m) + perpendicular2 * np.sin(angle_m)
+
     @check_input_types
     def get_angle_between(self, v: "Vector3D") -> Quantity:
         """Get the angle between this 3D vector and another 3D vector.

tests/test_math.py

@@ -24,6 +24,7 @@
 
 from beartype.roar import BeartypeCallHintParamViolation
 import numpy as np
+from pint import Quantity
 import pytest
 
 from ansys.geometry.core.math import (
@@ -628,6 +629,24 @@ def test_vector2d_errors():
         v1.get_angle_between(v2)
 
 
+def test_rotate_vector():
+    """Test the rotate_vector method."""
+    # Define the vectors and angle
+    axis = Vector3D([0.0, 0.0, 1.0])
+    vector = Vector3D([1.0, 0.0, 0.0])
+
+    angle = Quantity(np.pi / 2)  # 90 degrees
+
+    # Expected result after rotating vector around axis by 90 degrees
+    expected_vector = Vector3D([0.0, 1.0, 0.0])
+
+    # Call the method under test
+    result_vector = axis.rotate_vector(vector, angle)
+
+    # Assert that the result matches the expected vector
+    assert np.allclose(result_vector, expected_vector)
+
+
 def test_matrix():
     """Simple test to create a ``Matrix``."""
     # Create two matrix objects
@@ -828,6 +847,82 @@ def test_create_rotation_matrix():
     assert np.array_equal(expected_matrix, rotation_matrix)
 
 
+def test_create_matrix_from_rotation_about_axis_x():
+    """Test the create_matrix_from_rotation_about_axis method for rotation about the x-axis."""
+    axis = Vector3D([1.0, 0.0, 0.0])
+    angle = np.pi / 2  # 90 degrees
+    expected_matrix = Matrix44([[1, 0, 0, 0], [0, 0, -1, 0], [0, 1, 0, 0], [0, 0, 0, 1]])
+
+    result_matrix = Matrix44.create_matrix_from_rotation_about_axis(axis, angle)
+
+    print(result_matrix)
+    assert np.allclose(result_matrix, expected_matrix)
+
+
+def test_create_matrix_from_rotation_about_axis_y():
+    """Test the create_matrix_from_rotation_about_axis method for rotation about the y-axis."""
+    axis = Vector3D([0.0, 1.0, 0.0])
+    angle = np.pi / 2  # 90 degrees
+    expected_matrix = Matrix44([[0, 0, 1, 0], [0, 1, 0, 0], [-1, 0, 0, 0], [0, 0, 0, 1]])
+
+    result_matrix = Matrix44.create_matrix_from_rotation_about_axis(axis, angle)
+    assert np.allclose(result_matrix, expected_matrix)
+
+
+def test_create_matrix_from_rotation_about_axis_z():
+    """Test the create_matrix_from_rotation_about_axis method for rotation about the z-axis."""
+    axis = Vector3D([0.0, 0.0, 1.0])
+    angle = np.pi / 2  # 90 degrees
+    expected_matrix = Matrix44([[0, -1, 0, 0], [1, 0, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]])
+
+    result_matrix = Matrix44.create_matrix_from_rotation_about_axis(axis, angle)
+    assert np.allclose(result_matrix, expected_matrix)
+
+
+def test_create_matrix_from_rotation_about_arbitrary_axis():
+    """Test the create_matrix_from_rotation_about_axis method for
+    rotation about an arbitrary axis.
+    """
+    axis = Vector3D([1.0, 1.0, 1.0]).normalize()
+    angle = np.pi / 3  # 60 degrees
+    # Expected matrix calculated using external tools or libraries
+    expected_matrix = Matrix44(
+        [
+            [0.66666667, -0.33333333, 0.66666667, 0],
+            [0.66666667, 0.66666667, -0.33333333, 0],
+            [-0.33333333, 0.66666667, 0.66666667, 0],
+            [0, 0, 0, 1],
+        ]
+    )
+
+    result_matrix = Matrix44.create_matrix_from_rotation_about_axis(axis, angle)
+    assert np.allclose(result_matrix, expected_matrix)
+
+
+def test_create_matrix_from_mapping():
+    """Test the create_matrix_from_mapping method."""
+    # Define the frame with origin and direction vectors
+    origin = Vector3D([1.0, 2.0, 3.0])
+    direction_x = Vector3D([1.0, 0.0, 0.0])
+    direction_y = Vector3D([0.0, 1.0, 0.0])
+    frame = Frame(origin, direction_x, direction_y)
+
+    # Create the expected translation matrix
+    expected_translation_matrix = Matrix44.create_translation(origin)
+
+    # Create the expected rotation matrix
+    expected_rotation_matrix = Matrix44.create_rotation(direction_x, direction_y)
+
+    # Create the expected result by multiplying the translation and rotation matrices
+    expected_matrix = expected_translation_matrix * expected_rotation_matrix
+
+    # Call the method under test
+    result_matrix = Matrix44.create_matrix_from_mapping(frame)
+
+    # Assert that the result matches the expected matrix
+    assert np.allclose(result_matrix, expected_matrix)
+
+
 def test_frame():
     """``Frame`` construction and equivalency."""
     origin = Point3D([42, 99, 13])