User Experience Improvements to PyroSim 2021.1

Posted on February 15th, 2021

We are constantly taking feedback from our users and incorporating their suggestions in to our products to improve the user experience. In that vein, we have made several usability improvements to PyroSim in the 2021.1 release, some of which are mentioned below. You can view the full list on the PyroSim Release Notes page after the release on February 24th.

New Scenarios are now activated immediately after creation

Following the release of the Scenarios feature in version 2020.4, some users reported that they would create a new scenario and begin editing, only to realize that they had not switched over to the newly created scenario and had to undo their changes. We have updated the Scenarios tool so that when you create a new scenario it is automatically activated, and any changes that you make will be added to it by default. If you haven’t already, check out our Scenarios tutorial to learn the basics of how you can use the Scenarios feature in your workflow.

The drawing of individual points can be undone when using the wall or slab tools

Prior to version 2021.1, if you were to start drawing with either the wall or slab tools and make a mistake, there was not a way to undo the mistake. Using the Ctrl+Z shortcut would instead undo the last action outside of the tool. In version 2021.1 we have added the ability to undo individual points when using those tools, which will be especially helpful if you are drawing obstruction with a lot of vertices. You can see a short demonstration of the new undo action below.

The state of the FDS Blocks Preview is now remembered when you re-open your models

We had some users report that they found the FDS Blocks Preview very useful for verifying their models, but they saw performance issues when enabling/disabling the FDS Preview on larger models. This was exacerbated when they had to close and re-open models, and then had to switch to the FDS Blocks Preview. Because of this, we modified PyroSim to save the state of the FDS Blocks Preview when a model is saved. Now, if you are viewing the preview and close your model, the preview will be shown when you re-open the model.

Clicking a selected object in the Navigation Tree will open a renaming prompt

You can now rename most objects in the PyroSim navigation tree similar to how files can be renamed in the Windows File Explorer. Prior to this, the only way to rename objects was to right-click the object, then find the rename button to trigger the renaming prompt. Now, you can select an item in the Navigation tree and click it again a few milliseconds later to rename it.

New PyroSim Workshop Dates Available

Posted on November 3rd, 2020

Want to learn how to improve your fire modeling skills? Dave McGill has worked with Thunderhead Engineering to provide PyroSim and FDS training to hundreds of attendees for many years. We are excited to announce the latest dates, viewable at our online schedule, for his acclaimed courses in an online workshop format. … Read More

Save Settings for Results Visualizations

Posted on October 30th, 2019

The most recent release of the PyroSim and Pathfinder Results application allows users to create, save, and load results visualizations. A results visualization is a collection of settings that define which Pathfinder and FDS results are to be loaded and how those results are to be displayed. It also contains information entered by the user, such as views, tours, colorbar settings, time settings, annotations, object visibility, etc.

Results visualization files end with either .pfrv when saved from Pathfinder Results or .smvv when saved from PyroSim Results. When Pathfinder or FDS results are viewed from either Pathfinder or PyroSim for the first time, a results visualization is automatically created and saved containing the results data. The visualization file name will match that of the originating PTH or PSM file.


You can create multiple visualization files with different data sets (FDS and Pathfinder) and different saved states. This allows a user to reuse previous settings and to save particular visualization configurations for the same data set. This new feature also simplifies file management, as there is now a single visualization file with information that was previously stored in 3 different files (*.pfrmeta, *_resultsviews.json, and *_session.json), along with additional information that was not saved before.

The first version of results visualization available now allows you to save most settings. The rest will follow suit in the last release of the year.

PyroSim Keyboard Shortcuts

Posted on September 30th, 2019

A long-awaited feature has finally arrived, you can now assign Keyboard Shortcuts to various actions in PyroSim.

Overview of the UI

Open the Keyboard Shortcuts dialog through “File” > “Preferences..”. > “Keyboard Shortcuts: Edit…” button.

There are three tabs in this dialog window, ‘Global’, ‘View’ and ‘Tool’. Each tab contains a list of related functions that you can assign to a certain keystroke. For example, the ‘Copy’ function in PyroSim is mapped by default to the CTRL+C keypress combination.

How to set your own Keyboard Shortcuts

Step 1 – Open the Keyboard Shortcuts dialog through “File” > “Preferences…” > “Keyboard Shortcuts: Edit…” button.

Step 2 – Click the cell in the “Key Press” column that you want to assign to a new shortcut.

Step 3 – Press any Modifier Keys (optional) and the primary Key that you want to assign to that action. You can press a single key for an action. For example, you could map the ‘D’ key to the “New Device” action and then whenever you press the D key, the New Device tool will be activated. You can also clear existing shortcuts by clicking the ‘Clear’ button in this step.

If you have a keyboard or mouse that has ‘Macro’ keys or buttons, you will need to map keystrokes to the key/button first and then press this button during Step 3 above.


We set a few of the actions to some sensible defaults, but you are free to clear these out and create your own mapping. We did not create a default for all possible actions, so it will be up to you to set as many as you want.

Configuration File

Keyboard Shortcut settings are saved in a JSON formatted file “keybindings.json” stored in the C:\Users\[username]\AppData\Roaming\PyroSim directory. This file contains a mapping of each action to modifier keys (i.e. ALT, CTRL, SHIFT) and the keystroke for this action. The values in the modifiers and keystroke fields are common key codes for the keys on a keyboard.

With the Keyboard Shortcuts UI described above, you will not need to edit this file manually. This section is just to give you a look behind the scenes and show you what the file looks like in a text editor.

TIP: This file could be copied from one computer to another into the same location to allow Keyboard Shortcuts to be shared after they are mapped on one computer.

First Release and Room for Improvement

We are glad to have this new feature out of development and into the hands of our users. We have already started on this same feature for Pathfinder and hope to have it in the next release of it as well. Please feel free to provide us with any feedback you have on this feature, and all suggestions for improving functionality are welcome. Please send your thoughts to our Support Email address.

Dimensions and Labels for PyroSim and Pathfinder Results

Posted on May 9th, 2019

PyroSim 2019.1 and Pathfinder 2019.1 include linear dimensions and object labels as a tool in Results. This feature has been requested by users in order to provide a better documented report to officials.

“Inspectors, when verifying fire risk calculation reports, require the presence of object sizes on the plans so that they can verify the compliance of the calculation model.”

“It would be great if you add any instrument to create text on scene (rooms and doors names, dimensions etc.).”

This update allows the user to define and display the dimensions and labels as seen in the video below.

The information is dynamically displayed to adjust for better viewing as the camera rotates. Adding new dimensions or labels requires the user to select the appropriate tool and use the cursor to select the points they would like to highlight. The label tool displays the identified object as the user moves the cursor across an object. The dimensions and labels are saved as objects in Results that will persist across new simulations of a given model.

Top 10 Reasons You Should be Using the New Integrated PyroSim Results

Posted on April 10th, 2018

PyroSim now includes an integrated Results window. Here are the top 10 reasons you should be using it.

… Read More

Results Viewer Released in PyroSim 2017.2

Posted on November 15th, 2017

PyroSim will now install a new results viewer developed by Thunderhead Engineering to supplement Smokeview. Both will be included so that users can decide what is best for their needs. This new results application will allow us to further integrate information outside of FDS data such as Pathfinder evacuation simulations, CAD model textures, and camera tours designed in PyroSim. … Read More

PyroSim CAD File Import Improvements

Posted on April 12th, 2016

Earlier this year, Thunderhead Engineering released Pathfinder 2016.1 which included support for FBX and OBJ file formats in addition to graphical improvements for DXF and DWG. The PyroSim 2016.1 release also includes these improvements for advanced CAD import. Read more details on the new PyroSim CAD features in the Pathfinder 2016.1 import improvements post. … Read More

FDS Cluster Free Upgrade for PyroSim

Posted on March 28th, 2016

PyroSim 2016.1 is set to release in the next two weeks, including support for additional DEVC fields and new CAD file import options similar to those added in Pathfinder 2016.1. In addition, all PyroSim licenses will now include unrestricted use of the cluster simulation option. This is a permanent change which will automatically take effect, saving users 30% of the cost of purchasing PyroSim with the Unlimited Cluster Option. … Read More

Viewpoints and Section Boxes for Better Perspective

Posted on September 14th, 2015

PyroSim 2015.3 introduced two new tools to help engineers and their clients see the model in new ways. Viewpoints and section boxes, combined together to form a single view item, allow the user to save camera positions and clip geometry.

… Read More