13.1.9. Plotting OpenSees Tcl Output¶

OpenSees Tcl users can also take advantage of the plotting functions of OpenSeesPy Get_Rendering library. In order to do that, a Tcl script Get_Rendering.tcl to create an output database is used. First the user need to source Get_Rendering.tcl into the OpenSees tcl model file and then call the procedure to create an output database. This procedure does what createODB() does in OpenSeesPy. Once the output database is created, users can call plot_model(), plot_modeshape(), plot_deformedshape() and animate_deformedshape() commands. Compatibility with other commands will be added in the next release.

Download the Tcl script here Get_Rendering.tcl.

createODB "ModelName" "LoadCaseName" Nmodes

`ModelName` (str)	Name of the model the user wants to save database with. Folder name will be ModelName_ODB
`LoadCaseName` (str)	`"none"` or `"LoadCaseName"`. Name of the subfolder to save load case output data.
`Nmodes` (int)	`0` or `Nmodes (int)`. Number of modes to be saved for visualization.

Note: To record modeshape data, this procedure utilizes an internal Eigenvalue analysis. Make sure your model is well defined to avoid errors.

Example: Here is a minimal example of how to use Get_Rendering.tcl.

# source the script in the beginning of the Tcl script.
source Get_Rendering.tcl

# create model here.
# define nodes, elements etc.
# Once the model definition is finished, call the procedure to record the first 3 modeshapes.
# When recording modeshapes, use "none" for the loadCaseName.

createODB "3DBuilding" "none"  3

# The above command will save all the data in a folder named "3DBuilding_ODB" and ...
# ... a sub-folder "Modeshapes".

# Now to record data from a dynamic loadcase, assign a name for load case folder and ...
# ... the number 0 to Nmodes to avoid performing Eigenvalue analysis again.

createODB "3DBuilding" "Dynamic" 0

# The above command will save the node displacement data to a sub-folder "Dynamic" in ...
# ... the "3DBuilding_ODB" folder.

Now open a python terminal or Jupyter notebook and type the following. Make sure you install the latest version of OpenSeesPy first. Or, put the following lines in a Python script and run.

import openseespy.postprocessing.Get_Rendering as opsplt

# render the model with node and element tags on it
opsplt.plot_model("nodes","elements",Model=3DBuilding")

# plot mode shape 2 with a scale factor of 100
opsplt.plot_modeshape(2, 100, Model="3DBuilding")

# animate the deformed shape for dynaic analysis and save it as a 3DBuilding.mp4 file.
opsplt.animate_deformedshape(Model="3DBuilding", LoadCase="Dynamic", dt=0.01, Movie="3DBuilding")

All figures are interactive and can be saved as a .png file from the plot window.