Merge pull request #48 from scientificcomputing/dokken/pyvista-second-order

VTK second order cells for pyvista backend

Author: jorgensd

pyproject.toml

@@ -3,7 +3,7 @@ requires = ["setuptools>=61.0.0", "wheel"]
 
 [project]
 name = "io4dolfinx"
-version = "1.1.2"
+version = "1.2.0"
 description = "Checkpointing functionality for DOLFINx meshes/functions with ADIOS2"
 authors = [
     { name = "Jørgen S. Dokken", email = "dokken@simula.no" }, 
@@ -99,7 +99,7 @@ tag = true
 sign_tags = false
 tag_name = "v{new_version}"
 tag_message = "Bump version: {current_version} → {new_version}"
-current_version = "1.1.2"
+current_version = "1.2.0"
 
 
 [[tool.bumpversion.files]]

src/io4dolfinx/backends/pyvista/backend.py

@@ -44,6 +44,14 @@
     74: "pyramid",
 }
 
+_quadratric_vtk = {
+    21: "interval",
+    22: "triangle",
+    23: "quadrilateral",
+    24: "tetrahedron",
+    25: "hexahedron",
+}
+
 
 read_mode = ReadMode.serial
 
@@ -161,9 +169,14 @@ def read_mesh_data(
         if (cell_type := cell_types[0]) in _first_order_vtk.keys():
             cell_type = _first_order_vtk[cell_type]
             order = 1
+        elif cell_type in _quadratric_vtk.keys():
+            cell_type = _quadratric_vtk[cell_type]
+            order = 2
         elif cell_type in _arbitrary_lagrange_vtk.keys():
             cell_type = _arbitrary_lagrange_vtk[cell_type]
             order = _cell_degree(cell_type, cells.shape[1])
+        else:
+            raise NotImplementedError(f"Cell type {cell_type} not supported in Pyvista backend.")
         perm = dolfinx.cpp.io.perm_vtk(dolfinx.mesh.to_type(cell_type), cells.shape[1])
         cells = cells[:, perm]
         lvar = int(basix.LagrangeVariant.equispaced)