add open-usd exporter

doc/changelog.d/701.dependencies.md

@@ -0,0 +1 @@
+add open-usd exporter

pyproject.toml

@@ -82,7 +82,8 @@ doc = [
     "sphinxemoji==0.3.1",
 ]
 viz = [
-    "pyvista>=0.39.1"
+    "pyvista>=0.39.1",
+    "usd-core==24.3",
 ]
 
 [project.scripts]

src/ansys/mechanical/core/embedding/viz/usd_converter.py

@@ -0,0 +1,128 @@
+# Copyright (C) 2022 - 2024 ANSYS, Inc. and/or its affiliates.
+# SPDX-License-Identifier: MIT
+#
+#
+# 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.
+
+"""Converter to OpenUSD."""
+
+import typing
+
+import clr
+import numpy as np
+from pxr import Gf, Usd, UsdGeom
+
+clr.AddReference("Ansys.Mechanical.DataModel")
+clr.AddReference("Ansys.ACT.Interfaces")
+
+import Ansys  # isort: skip
+
+from .utils import bgr_to_rgb_tuple
+
+
+def _transform_to_rotation_quat(transform) -> Gf.Quatf:
+    transforms = [transform[i] for i in range(16)]
+    m = Gf.Matrix4d()
+    m.SetRow(0, transforms[0:4])
+    m.SetRow(1, transforms[4:8])
+    m.SetRow(2, transforms[8:12])
+    m.SetRow(3, transforms[12:16])
+
+    # TODO: m = m.GetTranspose() # if/when needed?
+
+    # Get quaternion from transformation matrix
+    quatd: Gf.Quatd = m.ExtractRotationQuat()
+
+    # Convert to single precision
+    quatf = Gf.Quatf(quatd)
+    return quatf
+
+
+def _reshape_3cols(arr: np.array, name: str):
+    err = f"{name} must be of the form (x0,y0,z0,x1,y1,z1,...,xn,yn,zn).\
+        Given {name} are not divisible by 3!"
+    assert arr.size % 3 == 0, err
+    numrows = int(arr.size / 3)
+    numcols = 3
+    arr = np.reshape(arr, (numrows, numcols))
+    return arr
+
+
+def _get_nodes_and_coords(tri_tessellation):
+    np_coordinates = _reshape_3cols(
+        np.array(tri_tessellation.Coordinates, dtype=np.double), "coordinates"
+    )
+    np_indices = _reshape_3cols(np.array(tri_tessellation.Indices, dtype=np.int32), "indices")
+    return np_coordinates, np_indices
+
+
+def _convert_tri_tessellation_node(
+    node: "Ansys.Mechanical.Scenegraph.TriTessellationNode",
+    stage: Usd.Stage,
+    path: str,
+    rgb: typing.Tuple[int, int, int],
+) -> Usd.Prim:
+    mesh_prim = UsdGeom.Mesh.Define(stage, path)
+    np_coordinates, np_indices = _get_nodes_and_coords(node)
+    mesh_prim.CreatePointsAttr(np_coordinates)
+    mesh_prim.CreateFaceVertexCountsAttr([3] * len(np_indices))
+    mesh_prim.CreateFaceVertexIndicesAttr(np_indices)
+    r, g, b = rgb
+    mesh_prim.GetDisplayColorAttr().Set([(r / 255, g / 255, b / 255)])
+    return mesh_prim
+
+
+def _convert_transform_node(
+    node: "Ansys.Mechanical.Scenegraph.TransformNode",
+    stage: Usd.Stage,
+    path: str,
+    rgb: typing.Tuple[int, int, int],
+) -> Usd.Prim:
+    prim = UsdGeom.Xform.Define(stage, path)
+    prim.AddOrientOp().Set(_transform_to_rotation_quat(node.Transform))
+    child_node = node.Child
+    if isinstance(child_node, Ansys.Mechanical.Scenegraph.TriTessellationNode):
+        _convert_tri_tessellation_node(
+            node.Child, stage, prim.GetPath().AppendPath("TriTessellation"), rgb
+        )
+    return prim
+
+
+def to_usd_stage(app: "ansys.mechanical.core.embedding.App", name: str) -> None:
+    """Convert mechanical scene to usd stage."""
+    stage = Usd.Stage.CreateNew(name)
+
+    root_prim = UsdGeom.Xform.Define(stage, "/root")  # "/hello"
+    # stage.SetDefaultPrim(root_prim)
+
+    category = Ansys.Mechanical.DataModel.Enums.DataModelObjectCategory.Body
+    bodies = app.DataModel.GetObjectsByType(category)
+    for body in bodies:
+        scenegraph_node = Ansys.ACT.Mechanical.Tools.ScenegraphHelpers.GetScenegraph(body)
+        _convert_transform_node(
+            scenegraph_node, stage, f"/root/body{body.ObjectId}", bgr_to_rgb_tuple(body.Color)
+        )
+
+    return stage
+
+
+def to_usd_file(app, path: str) -> None:
+    """Export mechanical scene to usd file."""
+    stage = to_usd_stage(app, path)
+    stage.GetRootLayer().Save()