Improvements in PyroSim 2021.3

Posted on September 1st, 2021

PyroSim 2021.3 focuses on expanding its application use cases by supporting the latest features of FDS 6.7.6. Additionally, this PyroSim release is supported by Results improvements which incorporate technology advancements in video rendering. … Read More

HCN Update for PyroSim 2021.3 and Free Combustion Calculator Update

Posted on August 18th, 2021

Hydrogen cyanide (HCN) reactions were added in FDS 6.7.6 and are supported in PyroSim 2021.3. As part of this update, we have added HCN support in our Combustion Calculator which helps solve the stoichiometric equation to define a reaction. This calculator is provided as a free download with an included tutorial. … Read More

PyroSim 2021.2.0610 Patch Release – Available Now

Posted on June 10th, 2021

An issue in the PyroSim toolbar was recently identified. When results are available for viewing, the View Results and Plot Results buttons are disabled. This issue was introduced in the 2021.2.0525 release of PyroSim. 

We have identified the problem, and have uploaded a patch release which addresses the bug. The updated version of PyroSim is available now.

… Read More

2021.2 Patch Release – Available Now

Posted on May 26th, 2021

One of our Reseller Partners identified an issue when dragging items in the navigation view. When this happens, the application freezes and requires a forced shutdown to proceed. This issue was introduced in the 2021.2.0512 release of both PyroSim and Pathfinder. 

We have identified the problem, and have uploaded patch releases that addresses the bug. The updated versions of PyroSim and Pathfinder are available now.

… Read More

Improvements in PyroSim 2021.2

Posted on May 10th, 2021

PyroSim 2021.2 includes usability improvements to better monitor FDS simulation progress and find objects in your model.

Added the ability to scroll away from the bottom of the Run FDS Console

As FDS continues to output new lines, the user’s scroll position is retained.

PyroSim 2021.2 includes an improvement to the Run Simulation dialog. In the new version, the FDS output in the Run Simulation dialog is prevented from dragging the user’s view along with it. This is useful if a user would like to examine a particular portion of the output while the simulation is still running.

Search with “whole word” and “case sensitive” options in Find dialog

Finding with Whole Word enabled refines the search term “Top” to exclude “TopLeft”.

PyroSim 2021.2 includes an improved Find dialog. This improved dialog includes the new “Whole Word” and “Case Sensitive” checkboxes, which constrain content matches to exact matches of the search term and case sensitive matches of the search term, respectively.

Accelerate Simulation Time with PyroSim Cloud Computing

Posted on April 15th, 2021

What is cloud computing?

Cloud computing is a tech industry term for a service which provides computing power on request. This service is provided remote, or “in the cloud”, so that the user can access these resources from their office. One common use for cloud computing is to gain access to powerful hardware which goes beyond the needs of day-to-day office work.

Why use cloud computing for FDS?

FDS simulations can require over a full 24 hours for large, complex, or long applications on a modern business PC. This brings several challenges. Some models may exceed the memory limitations of a desktop machine and are unable to complete.

It is not uncommon for large FDS models to require over 24 hours of simulation time on high-end business desktops.

Not all projects demand such a long amount of time. Many can be simulated within a single working day, while others can be split or coarsened in order to design iteratively. For some users, their needs never exceed these situations. It can be simpler and cheaper to maintain a local machine to process simulations of this scale.

For others, cloud computing simplifies an otherwise complicated purchase of a high up-front cost server system to scale with increasing needs. Services across many industries offer on-demand computing power with simplified billing and on-demand power. In either case, a modeler may simply want to offload their computing needs so that their main desktop or laptop can be used for other tasks while the simulation completes.

How is cloud computing used in PyroSim?

Cloud HPC now provides FDS on Cloud for the fire simulation industry. This service supports multiple FDS versions (including the most recent), scalable virtual CPU power to meet your needs, and the ability to monitor your simulation progress in real-time.

This dialog provides access to the users cloud computing account.

PyroSim supports the ability to run an FDS simulation in the cloud by integrating with CFD FEA Service’s Cloud HPC. The user inputs their credentials and desired provisions for the cloud instance. Once the simulation begins, users can use the cloud provider’s dashboard to manage their progress. To view pricing and receive more information, register with Cloud HPC.

Organize PyroSim Projects with Scenarios

Posted on April 13th, 2021

What are scenarios?

Scenarios in PyroSim are a tool which provides a quick method of organizing multiple instances of a given model, each with different sets of enabled/disabled objects. In the Edit Scenarios dialog, the modeler can manage these instances and choose which to actively work on. While a scenario is active, any objects that the modeler disables through the Navigation panel or 3D/2D view will display in the Disabled Objects field for quick reference. A Description field is provided for a custom text entry. … Read More

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.

Update: The 2021.1 PyroSim Release is available now

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.