Split up mesh creation functions

Author: gnath-aswin

examples/example_2_core_mesh_generation_functions.ipynb

@@ -80,7 +80,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "from meshpy.mesh_creation_functions.beam_basic_geometry import create_beam_mesh_line\n",
+    "from meshpy.mesh_creation_functions.beam_line import create_beam_mesh_line\n",
     "\n",
     "mesh = Mesh()\n",
     "material = beam_mat(radius=0.01)\n",
@@ -129,7 +129,7 @@
  ],
  "metadata": {
   "kernelspec": {
-   "display_name": "meshpy",
+   "display_name": "Python 3",
    "language": "python",
    "name": "python3"
   },
@@ -143,7 +143,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.12.8"
+   "version": "3.12.9"
   }
  },
  "nbformat": 4,

src/meshpy/mesh_creation_functions/applications/__init__.py

@@ -0,0 +1,22 @@
+# The MIT License (MIT)
+#
+# Copyright (c) 2018-2025 MeshPy Authors
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+"""This module contains application-oriented beam mesh generation functions."""

src/meshpy/mesh_creation_functions/beam_fibers_in_rectangle.py renamed to src/meshpy/mesh_creation_functions/applications/beam_fibers_in_rectangle.py

@@ -30,7 +30,7 @@
 
 from meshpy.core.geometry_set import GeometryName as _GeometryName
 from meshpy.core.geometry_set import GeometrySet as _GeometrySet
-from meshpy.mesh_creation_functions.beam_basic_geometry import (
+from meshpy.mesh_creation_functions.beam_line import (
     create_beam_mesh_line as _create_beam_mesh_line,
 )
 from meshpy.utils.nodes import check_node_by_coordinate as _check_node_by_coordinate

src/meshpy/mesh_creation_functions/beam_honeycomb.py renamed to src/meshpy/mesh_creation_functions/applications/beam_honeycomb.py

@@ -27,7 +27,7 @@
 from meshpy.core.geometry_set import GeometrySet as _GeometrySet
 from meshpy.core.mesh import Mesh as _Mesh
 from meshpy.core.rotation import Rotation as _Rotation
-from meshpy.mesh_creation_functions.beam_basic_geometry import (
+from meshpy.mesh_creation_functions.beam_line import (
     create_beam_mesh_line as _create_beam_mesh_line,
 )
 from meshpy.utils.nodes import get_min_max_nodes as _get_min_max_nodes

src/meshpy/mesh_creation_functions/beam_stent.py renamed to src/meshpy/mesh_creation_functions/applications/beam_stent.py

@@ -27,10 +27,10 @@
 from meshpy.core.geometry_set import GeometrySet as _GeometrySet
 from meshpy.core.mesh import Mesh as _Mesh
 from meshpy.core.rotation import Rotation as _Rotation
-from meshpy.mesh_creation_functions.beam_basic_geometry import (
+from meshpy.mesh_creation_functions.beam_arc import (
     create_beam_mesh_arc_segment_via_rotation as _create_beam_mesh_arc_segment_via_rotation,
 )
-from meshpy.mesh_creation_functions.beam_basic_geometry import (
+from meshpy.mesh_creation_functions.beam_line import (
     create_beam_mesh_line as _create_beam_mesh_line,
 )
 from meshpy.utils.nodes import get_min_max_nodes as _get_min_max_nodes

src/meshpy/mesh_creation_functions/beam_wire.py renamed to src/meshpy/mesh_creation_functions/applications/beam_wire.py

@@ -25,7 +25,7 @@
 
 from meshpy.core.geometry_set import GeometryName as _GeometryName
 from meshpy.core.geometry_set import GeometrySet as _GeometrySet
-from meshpy.mesh_creation_functions.beam_basic_geometry import (
+from meshpy.mesh_creation_functions.beam_line import (
     create_beam_mesh_line as _create_beam_mesh_line,
 )
 from meshpy.utils.nodes import check_node_by_coordinate as _check_node_by_coordinate

src/meshpy/mesh_creation_functions/beam_arc.py

@@ -0,0 +1,261 @@
+# The MIT License (MIT)
+#
+# Copyright (c) 2018-2025 MeshPy Authors
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+"""Functions to create beam meshes along arcs."""
+
+import warnings as _warnings
+
+import numpy as _np
+
+from meshpy.core.conf import mpy as _mpy
+from meshpy.core.mesh import Mesh as _Mesh
+from meshpy.core.rotation import Rotation as _Rotation
+from meshpy.mesh_creation_functions.beam_generic import (
+    create_beam_mesh_generic as _create_beam_mesh_generic,
+)
+from meshpy.utils.nodes import get_single_node as _get_single_node
+
+
+def create_beam_mesh_arc_segment_via_rotation(
+    mesh, beam_class, material, center, axis_rotation, radius, angle, **kwargs
+):
+    """Generate a circular segment of beam elements.
+
+    The circular segment is defined via a rotation, specifying the "initial"
+    triad of the beam at the beginning of the arc.
+
+    This function exists for compatibility reasons with older MeshPy implementations.
+    The user is encouraged to use the newer implementation create_beam_mesh_arc_segment_via_axis
+
+    Args
+    ----
+    mesh: Mesh
+        Mesh that the arc segment will be added to.
+    beam_class: Beam
+        Class of beam that will be used for this line.
+    material: Material
+        Material for this segment.
+    center: _np.array, list
+        Center of the arc.
+    axis_rotation: Rotation
+        This rotation defines the spatial orientation of the arc.
+        The 3rd base vector of this rotation is the rotation axis of the arc
+        segment. The segment starts in the direction of the 1st basis vector
+        and the starting point is along the 2nd basis vector.
+    radius: float
+        The radius of the segment.
+    angle: float
+        The central angle of this segment in radians.
+
+    **kwargs (for all of them look into create_beam_mesh_function)
+    ----
+    n_el: int
+        Number of equally spaced beam elements along the line. Defaults to 1.
+        Mutually exclusive with l_el.
+    l_el: float
+        Desired length of beam elements. Mutually exclusive with n_el.
+        Be aware, that this length might not be achieved, if the elements are
+        warped after they are created.
+
+    Return
+    ----
+    return_set: GeometryName
+        Set with the 'start' and 'end' node of the line. Also a 'line' set
+        with all nodes of the line.
+    """
+
+    # Convert the input to the one for create_beam_mesh_arc_segment_via_axis
+    axis = axis_rotation * [0, 0, 1]
+    start_point = center + radius * (axis_rotation * [0, -1, 0])
+    return create_beam_mesh_arc_segment_via_axis(
+        mesh, beam_class, material, axis, center, start_point, angle, **kwargs
+    )
+
+
+def create_beam_mesh_arc_segment_via_axis(
+    mesh,
+    beam_class,
+    material,
+    axis,
+    axis_point,
+    start_point,
+    angle,
+    **kwargs,
+):
+    """Generate a circular segment of beam elements.
+
+    The arc is defined via a rotation axis, a point on the rotation axis a starting
+    point, as well as the angle of the arc segment.
+
+    Args
+    ----
+    mesh: Mesh
+        Mesh that the arc segment will be added to.
+    beam_class: Beam
+        Class of beam that will be used for this line.
+    material: Material
+        Material for this segment.
+    axis: _np.array, list
+        Rotation axis of the arc.
+    axis_point: _np.array, list
+        Point lying on the rotation axis. Does not have to be the center of the arc.
+    start_point: _np.array, list
+        Start point of the arc.
+    angle: float
+        The central angle of this segment in radians.
+
+    **kwargs (for all of them look into create_beam_mesh_function)
+    ----
+    n_el: int
+        Number of equally spaced beam elements along the line. Defaults to 1.
+        Mutually exclusive with l_el.
+    l_el: float
+        Desired length of beam elements. Mutually exclusive with n_el.
+        Be aware, that this length might not be achieved, if the elements are
+        warped after they are created.
+
+    Return
+    ----
+    return_set: GeometryName
+        Set with the 'start' and 'end' node of the line. Also a 'line' set
+        with all nodes of the line.
+    """
+
+    # The angle can not be negative with the current implementation.
+    if angle <= 0.0:
+        raise ValueError(
+            "The angle for a beam arc segment has to be a positive number!"
+        )
+
+    # Shortest distance from the given point to the axis of rotation gives
+    # the "center" of the arc
+    axis = _np.asarray(axis)
+    axis_point = _np.asarray(axis_point)
+    start_point = _np.asarray(start_point)
+
+    axis = axis / _np.linalg.norm(axis)
+    diff = start_point - axis_point
+    distance = diff - _np.dot(_np.dot(diff, axis), axis)
+    radius = _np.linalg.norm(distance)
+    center = start_point - distance
+
+    # Get the rotation at the start
+    # No need to check the start node here, as eventual rotation offsets in
+    # tangential direction will be covered by the create beam functionality.
+    tangent = _np.cross(axis, distance)
+    tangent /= _np.linalg.norm(tangent)
+    start_rotation = _Rotation.from_rotation_matrix(
+        _np.transpose(_np.array([tangent, -distance / radius, axis]))
+    )
+
+    def get_beam_geometry(alpha, beta):
+        """Return a function for the position and rotation along the beam
+        axis."""
+
+        def beam_function(xi):
+            """Return a point and the triad on the beams axis for a given
+            parameter coordinate xi."""
+            phi = 0.5 * (xi + 1) * (beta - alpha) + alpha
+            arc_rotation = _Rotation(axis, phi)
+            rot = arc_rotation * start_rotation
+            pos = center + arc_rotation * distance
+            return (pos, rot, phi * radius)
+
+        return beam_function
+
+    # Create the beam in the mesh
+    return _create_beam_mesh_generic(
+        mesh,
+        beam_class=beam_class,
+        material=material,
+        function_generator=get_beam_geometry,
+        interval=[0.0, angle],
+        interval_length=angle * radius,
+        **kwargs,
+    )
+
+
+def create_beam_mesh_arc_segment_2d(
+    mesh, beam_class, material, center, radius, phi_start, phi_end, **kwargs
+):
+    """Generate a circular segment of beam elements in the x-y plane.
+
+    Args
+    ----
+    mesh: Mesh
+        Mesh that the arc segment will be added to.
+    beam_class: Beam
+        Class of beam that will be used for this line.
+    material: Material
+        Material for this segment.
+    center: _np.array, list
+        Center of the arc. If the z component is not 0, an error will be
+        thrown.
+    radius: float
+        The radius of the segment.
+    phi_start, phi_end: float
+        The start and end angles of the arc w.r.t the x-axis. If the start
+        angle is larger than the end angle the beam faces in counter-clockwise
+        direction, and if the start angle is smaller than the end angle, the
+        beam faces in clockwise direction.
+
+    **kwargs (for all of them look into create_beam_mesh_function)
+    ----
+    n_el: int
+        Number of equally spaced beam elements along the line. Defaults to 1.
+        Mutually exclusive with l_el.
+    l_el: float
+        Desired length of beam elements. Mutually exclusive with n_el.
+        Be aware, that this length might not be achieved, if the elements are
+        warped after they are created.
+
+    Return
+    ----
+    return_set: GeometryName
+        Set with the 'start' and 'end' node of the line. Also a 'line' set
+        with all nodes of the line.
+    """
+
+    # The center point has to be on the x-y plane.
+    if _np.abs(center[2]) > _mpy.eps_pos:
+        raise ValueError("The z-value of center has to be 0!")
+
+    # Check if the beam is in clockwise or counter clockwise direction.
+    angle = phi_end - phi_start
+    axis = _np.array([0, 0, 1])
+    start_point = center + radius * (_Rotation(axis, phi_start) * [1, 0, 0])
+
+    counter_clockwise = _np.sign(angle) == 1
+    if not counter_clockwise:
+        # If the beam is not in counter clockwise direction, we have to flip
+        # the rotation axis.
+        axis = -1.0 * axis
+
+    return create_beam_mesh_arc_segment_via_axis(
+        mesh,
+        beam_class,
+        material,
+        axis,
+        center,
+        start_point,
+        _np.abs(angle),
+        **kwargs,
+    )