Plot with mesh deformation

This tutorial shows different commands for plotting a deformed mesh without data.

A mesh is represented in DPF by a MeshedRegion. You can store multiple MeshedRegion objects in a DPF collection called MeshesContainer.

You can obtain a MeshedRegion by creating your own from scratch or by getting it from a result file. For more information, see the Create a mesh from scratch and Get a mesh from a result file tutorials.

PyDPF-Core has a variety of plotting methods for generating 3D plots with Python. These methods use VTK and leverage the PyVista library.

Load data to plot

import ansys.dpf.core as dpf
from ansys.dpf.core import examples, operators as ops

# Download and get the path to an example result file
result_file_path_1 = examples.download_piston_rod()

# Create a model from the result file
model_1 = dpf.Model(data_sources=result_file_path_1)

Get the deformation field

To deform the mesh, a nodal 3D vector field specifying the translation of each node in the mesh is needed.

The following DPF objects can represent such a field and are accepted as inputs for the deform_by parameter of all plot methods:

• A Field

• A FieldsContainer

• A result object

• An Operator

Here, we use the displacement operator, which outputs a nodal 3D vector field of distances. One can get the operator from the Model with the data source already connected. For more information about extracting results from a result file, see the Import Data tutorials section.

disp_op = model_1.results.displacement()

# Define the scale factor to apply to the deformation
scl_fct = 2.0

Plot a deformed model

Plot the overall mesh loaded by the model with Model.plot(). To add deformation, pass the displacement operator to the deform_by argument.

Note

The DpfPlotter displays the mesh with edges, lighting and axis widget enabled by default. You can pass additional PyVista arguments to all plotting methods to change the default behavior (see options for pyvista.plot()).

model_1.plot(deform_by=disp_op, scale_factor=scl_fct)

([], <pyvista.plotting.plotter.Plotter object at 0x0000013BD49A4290>)

Plot a single mesh

Get the mesh

meshed_region_1 = model_1.metadata.meshed_region

Plot the deformed mesh using MeshedRegion.plot()

Use the MeshedRegion.plot() method and pass the displacement operator to the deform_by argument.

meshed_region_1.plot(deform_by=disp_op, scale_factor=scl_fct)

([], <pyvista.plotting.plotter.Plotter object at 0x0000013BD44D8250>)

Plot the deformed mesh using DpfPlotter

1. Create an instance of DpfPlotter.

2. Add the mesh to the scene using add_mesh(), passing the displacement operator to the deform_by argument.

3. Render and show the figure using show_figure().

plotter_1 = dpf.plotter.DpfPlotter()
plotter_1.add_mesh(meshed_region=meshed_region_1, deform_by=disp_op, scale_factor=scl_fct)
plotter_1.show_figure()

([], <pyvista.plotting.plotter.Plotter object at 0x0000013BD9DBE9D0>)

You can also plot data contours on a deformed mesh. For more information, see Plot contours.

Plot several meshes

Build a collection of meshes

Use the split_mesh operator to split the mesh based on the material of each element. This operator returns a MeshesContainer with meshes labeled according to the split criterion. For more information, see the Split a mesh and Extract a mesh in split parts tutorials.

meshes = ops.mesh.split_mesh(mesh=meshed_region_1, property="mat").eval()
print(meshes)

DPF  Meshes Container
  with 2 mesh(es)
  defined on labels: body mat

  with:
  - mesh 0 {mat:  1, body:  1, } with 17281 nodes and 9026 elements.
  - mesh 1 {mat:  2, body:  2, } with 17610 nodes and 9209 elements.

Plot the deformed meshes

Use MeshesContainer.plot() and pass the displacement operator to deform_by. This plots all MeshedRegion objects in the MeshesContainer and colors them based on the split criterion.

meshes.plot(deform_by=disp_op, scale_factor=scl_fct)

([], <pyvista.plotting.plotter.Plotter object at 0x0000013BD49E9D50>)

You can also plot data on a collection of deformed meshes. For more information, see Plot contours.