mirror of
https://github.com/openmc-dev/openmc.git
synced 2026-07-28 14:15:42 -04:00
211 lines
9.1 KiB
ReStructuredText
211 lines
9.1 KiB
ReStructuredText
.. _usersguide_plots:
|
|
|
|
======================
|
|
Geometry Visualization
|
|
======================
|
|
|
|
.. currentmodule:: openmc
|
|
|
|
OpenMC is capable of producing two-dimensional slice plots of a geometry as well
|
|
as three-dimensional voxel plots using the geometry plotting :ref:`run mode
|
|
<usersguide_run_modes>`. The geometry plotting mode relies on the presence of a
|
|
:ref:`plots.xml <io_plots>` file that indicates what plots should be created. To
|
|
create this file, one needs to create one or more :class:`openmc.Plot`
|
|
instances, add them to a :class:`openmc.Plots` collection, and then use the
|
|
:class:`Plots.export_to_xml` method to write the ``plots.xml`` file.
|
|
|
|
-----------
|
|
Slice Plots
|
|
-----------
|
|
|
|
.. image:: ../_images/atr.png
|
|
:width: 300px
|
|
|
|
By default, when an instance of :class:`openmc.Plot` is created, it indicates
|
|
that a 2D slice plot should be made. You can specify the origin of the plot
|
|
(:attr:`Plot.origin`), the width of the plot in each direction
|
|
(:attr:`Plot.width`), the number of pixels to use in each direction
|
|
(:attr:`Plot.pixels`), and the basis directions for the plot. For example, to
|
|
create a :math:`x` - :math:`z` plot centered at (5.0, 2.0, 3.0) with a width of
|
|
(50., 50.) and 400x400 pixels::
|
|
|
|
plot = openmc.Plot()
|
|
plot.basis = 'xz'
|
|
plot.origin = (5.0, 2.0, 3.0)
|
|
plot.width = (50., 50.)
|
|
plot.pixels = (400, 400)
|
|
|
|
The color of each pixel is determined by placing a particle at the center of
|
|
that pixel and using OpenMC's internal ``find_cell`` routine (the same one used
|
|
for particle tracking during simulation) to determine the cell and material at
|
|
that location.
|
|
|
|
.. note:: In this example, pixels are 50/400=0.125 cm wide. Thus, this plot may
|
|
miss any features smaller than 0.125 cm, since they could exist
|
|
between pixel centers. More pixels can be used to resolve finer
|
|
features but will result in larger files.
|
|
|
|
By default, a unique color will be assigned to each cell in the geometry. If you
|
|
want your plot to be colored by material instead, change the
|
|
:attr:`Plot.color_by` attribute::
|
|
|
|
plot.color_by = 'material'
|
|
|
|
If you don't like the random colors assigned, you can also indicate that
|
|
particular cells/materials should be given colors of your choosing::
|
|
|
|
plot.colors = {
|
|
water: 'blue',
|
|
clad: 'black'
|
|
}
|
|
|
|
# This is equivalent
|
|
plot.colors = {
|
|
water: (0, 0, 255),
|
|
clad: (0, 0, 0)
|
|
}
|
|
|
|
Note that colors can be given as RGB tuples or by a string indicating a valid
|
|
`SVG color <https://www.w3.org/TR/SVG11/types.html#ColorKeywords>`_.
|
|
|
|
When you're done creating your :class:`openmc.Plot` instances, you need to then
|
|
assign them to a :class:`openmc.Plots` collection and export it to XML::
|
|
|
|
plots = openmc.Plots([plot1, plot2, plot3])
|
|
plots.export_to_xml()
|
|
|
|
# This is equivalent
|
|
plots = openmc.Plots()
|
|
plots.append(plot1)
|
|
plots += [plot2, plot3]
|
|
plots.export_to_xml()
|
|
|
|
To actually generate the plots, run the :func:`openmc.plot_geometry` function.
|
|
Alternatively, run the :ref:`scripts_openmc` executable with the ``--plot``
|
|
command-line flag. When that has finished, you will have one or more ``.png``
|
|
files. Alternatively, if you're working within a `Jupyter
|
|
<https://jupyter.org/>`_ Notebook or QtConsole, you can use the
|
|
:func:`openmc.plot_inline` to run OpenMC in plotting mode and display the
|
|
resulting plot within the notebook.
|
|
|
|
.. _usersguide_voxel:
|
|
|
|
-----------
|
|
Voxel Plots
|
|
-----------
|
|
|
|
.. image:: ../_images/3dba.png
|
|
:width: 200px
|
|
|
|
The :class:`openmc.Plot` class can also be told to generate a 3D voxel plot
|
|
instead of a 2D slice plot. Simply change the :attr:`Plot.type` attribute to
|
|
'voxel'. In this case, the :attr:`Plot.width` and :attr:`Plot.pixels` attributes
|
|
should be three items long, e.g.::
|
|
|
|
vox_plot = openmc.Plot()
|
|
vox_plot.type = 'voxel'
|
|
vox_plot.width = (100., 100., 50.)
|
|
vox_plot.pixels = (400, 400, 200)
|
|
|
|
The voxel plot data is written to an :ref:`HDF5 file <io_voxel>`. The voxel file
|
|
can subsequently be converted into a standard mesh format that can be viewed in
|
|
`ParaView <https://www.paraview.org/>`_, `VisIt
|
|
<https://wci.llnl.gov/simulation/computer-codes/visit>`_, etc. This typically
|
|
will compress the size of the file significantly. The provided
|
|
:ref:`scripts_voxel` script can convert the HDF5 voxel file to VTK formats. Once
|
|
processed into a standard 3D file format, colors and masks can be defined using
|
|
the stored ID numbers to better explore the geometry. The process for doing this
|
|
will depend on the 3D viewer, but should be straightforward.
|
|
|
|
.. note:: 3D voxel plotting can be very computer intensive for the viewing
|
|
program (Visit, ParaView, etc.) if the number of voxels is large (>10
|
|
million or so). Thus if you want an accurate picture that renders
|
|
smoothly, consider using only one voxel in a certain direction.
|
|
|
|
----------------
|
|
Projection Plots
|
|
----------------
|
|
|
|
.. only:: html
|
|
|
|
.. image:: ../_images/hexlat_anim.gif
|
|
:width: 200px
|
|
|
|
The :class:`openmc.ProjectionPlot` class presents an alternative method of
|
|
producing 3D visualizations of OpenMC geometries. It was developed to overcome
|
|
the primary shortcoming of voxel plots, that an enormous number of voxels must
|
|
be employed to capture detailed geometric features. Projection plots perform
|
|
volume rendering on material or cell volumes, with colors specified in the same
|
|
manner as slice plots. This is done using the native ray tracing capabilities
|
|
within OpenMC, so any geometry in which particles successfully run without
|
|
overlaps or leaks will work with projection plots.
|
|
|
|
One drawback of projection plots is that particle tracks cannot be overlaid on
|
|
them at present. Moreover, checking for overlap regions is not currently
|
|
possible with projection plots. The image heading this section can be created by
|
|
adding the following code to the hexagonal lattice example packaged with OpenMC,
|
|
before exporting to plots.xml.
|
|
|
|
::
|
|
|
|
r = 5
|
|
import numpy as np
|
|
for i in range(100):
|
|
phi = 2 * np.pi * i/100
|
|
thisp = openmc.ProjectionPlot(plot_id = 4 + i)
|
|
thisp.filename = 'frame%s'%(str(i).zfill(3))
|
|
thisp.look_at = [0, 0, 0]
|
|
thisp.camera_position = [r * np.cos(phi), r * np.sin(phi), 6 * np.sin(phi)]
|
|
thisp.pixels = [200, 200]
|
|
thisp.color_by = 'material'
|
|
thisp.colorize(geometry)
|
|
thisp.set_transparent(geometry)
|
|
thisp.xs[fuel] = 1.0
|
|
thisp.xs[iron] = 1.0
|
|
thisp.wireframe_domains = [fuel]
|
|
thisp.wireframe_thickness = 2
|
|
|
|
plot_file.append(thisp)
|
|
|
|
This generates a sequence of png files which can be joined to form a gif. Each
|
|
image specifies a different camera position using some simple periodic functions
|
|
to create a perfectly looped gif. :attr:`ProjectionPlot.look_at` defines where
|
|
the camera's centerline should point at. :attr:`ProjectionPlot.camera_position`
|
|
similarly defines where the camera is situated in the universe level we seek to
|
|
plot. The other settings resemble those employed by :class:`openmc.Plot`, with
|
|
the exception of the :class:`ProjectionPlot.set_transparent` method and
|
|
:attr:`ProjectionPlot.xs` dictionary. These are used to control volume rendering
|
|
of material volumes. "xs" here stands for cross section, and it defines material
|
|
opacities in units of inverse centimeters. Setting this value to a large number
|
|
would make a material or cell opaque, and setting it to zero makes a material
|
|
transparent. Thus, the :class:`ProjectionPlot.set_transparent` can be used to
|
|
make all materials in the geometry transparent. From there, individual material
|
|
or cell opacities can be tuned to produce the desired result.
|
|
|
|
Two camera projections are available when using these plots, perspective and
|
|
orthographic. The default, perspective projection, is a cone of rays passing
|
|
through each pixel which radiate from the camera position and span the field of
|
|
view in the x and y positions. The horizontal field of view can be set with the
|
|
:attr: `ProjectionPlot.horizontal_field_of_view` attribute, which is to be
|
|
specified in units of degrees. The field of view only influences behavior in
|
|
perspective projection mode.
|
|
|
|
In the orthographic projection, rays follow the same angle but originate from
|
|
different points. The horizontal width of this plane of ray starting points may
|
|
be set with the :attr: `ProjectionPlot.orthographic_width` element. If this
|
|
element is nonzero, the orthographic projection is employed. Left to its default
|
|
value of zero, the perspective projection is employed.
|
|
|
|
Lastly, projection plots come packaged with wireframe generation that can target
|
|
either all surface/cell/material boundaries in the geometry, or only wireframing
|
|
around specific regions. In the above example, we have set only the fuel region
|
|
from the hexagonal lattice example to have a wireframe drawn around it. This is
|
|
accomplished by setting the :attr: `ProjectionPlot.wireframe_domains`, which may
|
|
be set to either material IDs or cell IDs. The
|
|
:attr:`ProjectionPlot.wireframe_thickness` attribute sets the wireframe
|
|
thickness in units of pixels.
|
|
|
|
.. note:: When setting specific material or cell regions to have wireframes
|
|
drawn around them, the plot must be colored by materials if wireframing
|
|
around specific materials and similarly colored by cell instance if
|
|
wireframing around specific cells.
|