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Pathfinder Fundamentals

Reading Time: 18 minutes

1. Overview

This tutorial is specifically designed for individuals who are new to using Pathfinder. In this course, we will provide a step-by-step demonstration of how to create a basic evacuation simulation in Pathfinder and provide an explanation of some of the underlying concepts. By the end of this tutorial you will have gained proficiency in navigating the Pathfinder interface, running a simulation, and interpreting the results.

2. Prerequisites

  1. Download and install the latest version of Pathfinder from the Pathfinder Support page.
  2. If you haven’t already, sign up for a free 30-day trial license or purchase a license.
  3. Visit the latest version of the Pathfinder User Manual for reference throughout this tutorial.

3. What is Pathfinder?

Welcome to the very first tutorial on creating fire models in Pathfinder. Before jumping into things, it is important to briefly go over what Pathfinder is.

Pathfinder is an agent-based egress simulator that uses steering behaviors to model occupant motion. It consists of three modules: a graphical user interface (preprocessor), the simulator, and a 3D results viewer (postprocessor).

Pathfinder provides two primary options for occupant motion; SFPE mode and Steering mode.

3.1. SFPE mode (Chapter 5)

Implements the concepts in the SFPE Handbook of Fire Protection Engineering (SFPE 2016). This is a flow model, where walking speeds are determined by occupant density within each room, and flow through doors is controlled by door width.

3.2. Steering mode (Chapter 6)

Based on the idea of inverse steering behaviors. Steering behaviors were first presented in Craig Reinolds' paper "Steering Behaviors For Autonomous Characters" (Reinolds 1999) and later refined into inverse steering behaviors in a paper by Heni Ben Amor (Amor et al. 2006). Pathfinder’s steering mode allows more complex behavior to naturally emerge as a byproduct of the movement algorithms - eliminating the need for explicit door queues and density calculations.

4. Explore the Interface

In this section and its sub-sections, you will use an existing model to learn the basic operations of Pathfinder.

  1. Download the Pathfinder Fundamentals zip file.
  2. Open Windows Explorer and browse to the downloaded file.
  3. Right-click pathfinder-fundamentals.zip and click Extract All.
  4. From the extracted folder, open Fundamentals.pth to launch Pathfinder with that model.
  5. Review the interface elements as shown in Figure 1. These will be often referred to throughout this series.
path ui toolbar general
Figure 1. Highlighted Pathfinder User Interface Elements.

4.1. View a Model

This section will demonstrate some of the basic options to control your view of the model. Select the various options in the View toolbar and manipulate the 3D view.

  1. On the View toolbar, click path ui icon view 3d Switch to the Perspective View.

  1. On the View toolbar, click path ui icon orbit 3D Orbit Navigation.
  2. Drag the mouse to rotate the camera.
  3. Hold down Shift while dragging the mouse to pan the camera.
  4. Rotate the mouse wheel, or hold down Alt while dragging the mouse, to zoom the camera.

  5. On the View toolbar, click path ui icon view 2d top Switch to the Top View.

  1. On the View toolbar, click path ui icon select Select/Edit Objects.
  2. Hold down the left mouse button and drag to select objects.
  3. Hold down the right mouse button and drag to pan the camera.
  4. Rotate the mouse wheel to zoom the camera.
path ui view model
Figure 2. Basic Pathfinder View Interface.

You have successfully learned the basics of viewing a model.

4.2. Manage Objects

In this section, you will learn how to use the Navigation panel to view, hide, and select objects.

  1. On the View toolbar, click path ui icon view 3d Switch to the Perspective View.
  2. On the Navigation panel on the Floor list, select path ui icon floor Floor 0.0 ft to show only its objects.
  3. On the Navigation panel, right-click path ui icon floor Floor 10.0 ft and click Show to add its objects to the current view.
  4. On the 3D view, right-click any object and click Hide to remove it from the current view.
  5. On the 3D view, right-click any empty space and click Show All to bring all objects back into the current view.
  6. On the Navigation panel, select path ui icon auto expand Auto Expand Selection.
  7. On the 3D view, click any object. The Navigation panel expands and highlights the matching object in the list.
path ui view manage objects
Figure 3. Pathfinder Object Selection.

You have successfully learned the basics of managing objects in the Navigation panel.

4.3. Run a Simulation

In this section, you will learn how to initiate a simulation and analyze the results.

  1. On the Main toolbar, click Run Simulation.

  2. On the Results window, click Run. The simulation will play until all occupants have exited the model, and should appear similar to Figure 4.
  3. On the Playback toolbar, click Increase Speed to play the results two times faster than real time.
  4. Close the Results window and the Run Simulation dialog box.
path ui view run simulation
Figure 4. Example Pathfinder Simulation.

You have successfully learned the basics of running a simulation.

5. Create a New Model

In this section and its subsections, you will create a complete model which can be used in a simulation. The steps in this section demonstrate the fundamental parts of building a model in Pathfinder.

  1. On the Main toolbar, click path ui icon new model New Model. If prompted by the Save Changes dialog box, click No.
  2. On the Main toolbar, select path ui icon en Show values in EN units.
  3. On the Main toolbar, click path ui icon save model Save model.
  4. Create a new folder named Getting Started, and name the file myFundamentals.pth.
path ui dialog file
Figure 5. Pathfinder File Dialog.

You have successfully created and configured a new model.

5.1. Import Geometry

In this section, you will import geometry from a model created in another CAD application. This will allow you to draw the navigation mesh faster than starting from a blank file.

  1. On the Main toolbar and click path ui icon import Import File.
  2. Navigate to the Pathfinder-Fundamentals folder extracted from pathfinder-fundamentals.zip and open pathfinder-fundamentals.dwg.
  3. On the Import dialog box, select Into the current model and click Next.
  4. Select mm as the file’s length unit and click Next.
  5. Click Calculate to view information about the model with the selected units to ensure that the selected units are correct. The Model Height for this file is 70.0 ft and is confirmed in this dialog box.
  6. Use the default import settings and click Next.
  7. Click Finish to import the file.
path scrn fundamentals imported geometry
Figure 6. Example Imported External Geometry.

You have successfully imported the model.

5.2. Extract Floor

In this section, you will create a navigation mesh over the imported floor so that rooms, doors, and occupants can be created.

  1. On the Draw toolbar, click path ui icon extract floor Extract Floor from Imported Geometry.
  2. On the 3D view, click anywhere on the surface of the first floor.
  3. On the View toolbar, clear path ui icon show imported Show Imported Geometry.
path scrn fundamentals imported floor
Figure 7. Extracted Floor from Imported Geometry.

You have successfully extracted the first floor.

5.3. Create Doors

In this section, you will create doors over the imported geometry so that rooms are connected and occupants can make decisions about where to go.

  1. On the Draw toolbar, double-click path ui icon door Add a New Door.

  1. On the property panel in the Max Width box, type 60 in.

  2. On the property panel in the Max Depth box, type 10 in. Press Enter to set the value.

  1. On the 3D view, zoom in on a particular doorway. Point to the center of the doorway so that the door is previewed and click on the doorway.
path scrn fundamentals create doors 2024 1
Figure 8. The door will preview when you have placed the pointer in an appropriate doorway.
  1. Repeat step 5 for each of the 11 doorways. The individual rooms of the first floor are automatically created as the doors are added.
  2. On the 3D view, point to a corner of the outer grounds. Drag to an adjacent corner.
  1. Repeat step 7 for the other three sides of the outer grounds.
  2. Press Esc once all doors have been created to close the door tool.
path scrn fundamentals complete doors preview
Figure 9. Complete Floor Door Preview.

5.4. Create Occupants

In this section, you will add occupants to the rooms.

  1. On the Navigation panel, select path ui icon floor Floor 0.0 ft.
  2. On the 3D view, hold down Ctrl and click the elevator rooms and the outdoor floor to unselect.
path scrn fundamentals room selection
Figure 10. Your selection should include all of the main rooms.
  1. On the 3D view, right-click any selected area and click Add Occupants.
  2. In the Add Occupants dialog box, enter "Floor 1" in the Group Name and then in the By Number box, type 100 and click OK.
path scrn fundamentals create occupants
Figure 11. 100 agents distributed between the selected rooms.

Now that you have created occupants on the first floor, you can run a test simulation to check that everything is set up properly.

6. Add Floors

In this section and its subsections, you will complete the rest of the geometry by adding components for multi-floor models.

  1. At the top of the Navigation panel, in the Floor list dropdown, select Add New.
  2. On the New Floor dialog box in the Enter Floor Location box, type 10 ft and click OK.
  3. Repeat steps 1 - 2 for each floor until you have created path ui icon floor Floor 60.0 ft.
  4. On the View toolbar, select path ui icon show imported Show Imported Geometry.

  5. At the top of the Navigation panel, in the Floor list dropdown box, select path ui icon floor Floor 10.0 ft.

  6. On the 3D view, right-click the Floor 10.0 ft ceiling and click Hide.
path scrn fundamentals hidden ceiling
Figure 12. Floor 10.0 ft with the ceiling hidden so the floor and walls of the imported geometry are visible.
  1. On the Draw toolbar, click path ui icon extract floor Extract Floor from Imported Geometry.
  2. On the 3D view, click anywhere on Floor 10.0 ft.
  3. On the View toolbar, clear path ui icon show imported Show Imported Geometry.
  4. Hide the imported geometry and then add nine doors, similar to Floor 0.0 ft in Section 5.4, excluding the elevator room doors.
  5. On the Navigation panel, right-click path ui icon floor Floor 10.0 ft and click Add Occupants.
  6. In the Add Occupants dialog box, enter "Floor 2" for the Group Name and in the By Number box, type 100 and click OK.
path scrn fundamentals completed second floor
Figure 13. Completed Second Floor.

6.1. Copy Floors and Occupants

In this section, you will copy objects from the second floor to other floors of the model. This saves time because the middle floors are identical.

  1. On the Navigation panel, expand the Occupants list.
  2. On the Navigation panel, select path ui icon floor Floor 10.0 ft. Hold down the control key and select the "Floor 2" occupant group.
  3. On the Draw toolbar, click path ui icon copy move Copy/Move Objects.
  4. On the property panel, select Copy Mode.
  5. On the property panel in the Copies box, type 4.
  6. On the property panel in the Move Z box, type 10 ft.

  7. On the property panel, click Copy/Move.

  8. On the Navigation panel, select each copied occupant group. Right click any of the selected items and click Rename…​ to open the Rename dialog.
  9. In the Rename dialog, select the Rename with Template checkbox and in the Enter the new name: box type 'Floor ${local_index}' and click OK to quickly rename all items.

6.2. Add Rooftop Floor

The top floor is different than the middle floors, so we need to extract it separately.

  1. On the Navigation panel, right-click path ui icon floor Floors and click Show.
  2. On the View toolbar, select path ui icon show imported Show Imported Geometry.
  3. On the Draw toolbar, click path ui icon extract floor Extract Floor from Imported Geometry.
  4. On the 3D view, click anywhere on the rooftop floor.
  5. On the Navigation panel, right-click path ui icon floor Floor 60.0 ft and click Add Occupants.
  6. On the Add Occupants dialog box, name the group 'Rooftop Floor' and in the By Number box, type 100 and click OK.

6.3. Create Landing and Stairs

In this section, you will create a navigation mesh over the imported stairs so that occupants can traverse between floors.

  1. On the Navigation panel in the Floor list, select Show All.
  2. On the View toolbar, select path ui icon show imported Show Imported Geometry.
  3. On the Draw toolbar, click path ui icon extract floor Extract Floor from Imported Geometry
  4. On the 3D view, click anywhere on the landing connected to the four stairs.
path scrn fundamentals create stairs
Figure 14. The landing should connect to the four stairs.
  1. On the View toolbar, clear path ui icon show imported Show Imported Geometry.
  2. On the Draw toolbar, click path ui icon stair 2 Create stairs between two edges by choosing a point on each.

  3. For one of the four stairs connected to the bottom landing, click a point along the bottom and top edge to create the stairs.

  4. Repeat steps 6 - 7 for the other three stairs connected to the bottom landing.
path scrn fundamentals completed stairs
Figure 15. Completed Stairs and Landing.

6.4. Copy Landings and Stairs

Again we will use the copy feature within Pathfinder to save time, while duplicating repeating geometry in the vertical direction.

  1. On the 3D view, hold down Ctrl while clicking the four stairs and the landing.
  2. On the Draw toolbar, click path ui icon copy move Copy/Move Objects.
  3. On the property panel, select Copy Mode.
  4. On the property panel in the Copies box, type 5.
  5. On the property panel in the Move Z box, type 10 ft.
  6. On the property panel, click Copy/Move.
path scrn fundamentals copied geometry
Figure 16. Copied Geometry.

6.5. Create Elevators

In this section, you will create elevators. This will complete the model’s geometry.

  1. On the Navigation panel in the Floor list, select path ui icon floor Floor 0.0 ft.
  2. On the View toolbar, clear path ui icon show imported Show Imported Geometry.
  3. On the 3D view, right-click one of the two elevator rooms and click Create Elevator.
  4. On the New Elevator dialog box, click OK.
  5. Repeat steps 3-4 for the other elevator room.
path scrn fundamentals create elevators
Figure 17. Elevator Creation Preview.

7. Modify Occupants

In this section and its subsections, you will customize the way that the occupants interact with the model. This allows for greater customization and accuracy in various scenarios.

  1. On the Navigation panel in the Floor list, select Show All.
  2. Expand the path ui icon occupant group Occupants list.
  3. On the Navigation panel, select the Floor 1 occupant group.
  4. On the property panel, select Color, and click the color box.

  5. On the Color dialog box in the Color Code box, type FF2222, and click OK.

  6. Repeat steps 5 - 7 for Floor 2 - Floor 6 occupant groups to make them each different colors. Leave the Rooftop occupant group as their default color.
path scrn fundamentals modify occupants
Figure 18. Modified Occupants.

7.1. Create Behaviors

In this section, you will create a behavior for occupants to use the elevator. During evacuation, it has been observed that occupants on lower floors are more likely to use stairs than occupants on higher floors. We will use behaviors to assign different probabilities of stair usage by floor. In general, behaviors define a list of goals that occupants will accomplish before they exit or go to a refuge room.

  1. On the Navigation panel, right-click path ui icon behaviors Behaviors and click New Behavior.
  2. On the New Behavior dialog box in the Name box, type Elevator and click OK.
  3. On the property panel, select path ui icon elevators Goto Elevators from the Add Action list.
  4. On the property panel, click Create.
  5. On the Navigation panel, right-click the path ui icon occupant group Floor 3 occupant group and click Properties.
  6. On the Edit Selected Occupants dialog box, click the Behavior link.
  7. On the Behavior dialog box, enter 10 next to the Elevator behavior and enter 90 next to the Goto Any Exit behavior.
  8. Click OK on both dialog boxes.
  9. Repeat steps 5 - 8 for the Floor 4 and Floor 5 occupant groups. Use 20 and 80 as the Elevator and Goto Any Exit distribution percentages.
  10. Repeat steps 5 - 8 for the Floor 6 and Rooftop occupant groups. Use 30 and 70 as the Elevator and Goto Any Exit distribution percentages.
path scrn fundamentals create behaviors
Figure 19. Add Behaviors to Occupants.

7.2. Create Profiles

In this section you will create occupant profiles so that each individual occupant has different characteristics.

  1. On the Navigation panel, right-click path ui icon profiles Profiles and click Add a Profile.
  2. On the New Profile dialog box in the Name box, type Office and click OK.
  3. on the Navigation panel, right-click the new created Office profile and click Properties.
  4. On the Edit Profiles dialog box on the 3D Model box, click the list of models.
  5. On the 3D Model dialog box, select models that represent a typical office environment and click OK.
  6. On the Edit Profiles dialog box on the Characteristics tab in the Speed list, select Uniform.
  7. In the Speed list, click Edit to open the Uniform Distribution dialog box.
  8. On the Uniform Distribution dialog box in the Min box, type 2.0.
  9. On the Uniform Distribution dialog box in the Max box, type 4.3 and click OK.
  10. On the Edit Profiles dialog box, click Apply.
  11. On the Edit Profiles dialog box, click New.
  12. Repeat steps 2 - 8 for an Apartment profile. Use casually dressed models. Use a uniform speed of [3.0 ft/s, 5.3 ft/s] and click Apply.
  13. On the Edit Profiles dialog box, select Default and click Delete.

  14. On the Remove dialog box, click Yes. On the Profile in Use dialog box on the Replace with box, select Office and click OK.

    path ui create profiles fundamentals
    Figure 20. The Profiles are Ready to be Assigned.
  15. On the Edit Profiles dialog box, click OK.
  16. On the Navigation panel, right-click the path ui icon occupant group Rooftop occupant group and click Properties.
  17. On the Edit Selected Occupants dialog box, click the Profile link.
  18. On the Profile dialog box in the Rooftop box, click Distribute Evenly and click OK.
  19. On the Edit Group Distributions dialog box, click OK.
  20. Repeat steps 14 - 17 for path ui icon floor Floor 5 - path ui icon floor Floor 6 and assign 100% of the occupants the Apartment profile.
path ui dialog profiles distributions
Figure 21. Assigned Profile Distributions.

8. Analyze Results

In this section and its subsections, you will compile a simulation, explore the post-processing options, and create a video report.

  1. On the Main toolbar, click path ui icon run sim Run Simulation.
  2. Close the Run Simulation dialog box when the simulation is finished running.
  3. On the Main toolbar, click path ui icon view usage View Room Usage.
  4. On the Occupant Counts window on the Navigation panel, clear all and select Level 0.0 ft. This is the usage of the first elevator.
  5. Close the Occupant Counts window.
plot graph pathfundamentals occupants vs time
Figure 22. Occupants Plotted Against Time.

You have successfully compiled the simulation and viewed the first results option in Pathfinder.

8.1. Modify Visualization Contours

In this section, you will load contour plot data and modify the output display.

Adding Feathering to the plot will hide some of the noise and clean up the visualization. To add feathering:

  1. On the Main toolbar, click path ui icon results View 3D Results.
  2. On the 3D Results window on the Navigation panel, double-click the path ui icons contours Time to Exit contour plot.
  3. On the Optimize Contour dialog box, click Yes.
  4. Once the Generating Occupant Contour dialog box has completed, click path-ui-icon-play Play to view the results with the contour overlay.
  5. On the Navigation panel, right-click the path ui icons contours Time to Exit contour plot and click Properties.
  6. On the Time to Exit Properties dialog box, in the Opacity Source dropdown, select feather below.
  7. In the Feather Threshold box below the Opacity Source dropdown, type 1 and click OK.
path ui view contour view
Figure 23. Contour View.

You have successfully modified and viewed a contour plot.

8.2. Create Camera Tour

In this section, you will create a camera tour to highlight key areas in the simulation. These instructions are for Pathfinder 2018.3 and later where we create the camera tour in the Results view. In earlier versions, you create the camera tour in Pathfinder.

  1. In the Results view, on the Navigation panel right-click path ui icon views Views and click New Tour.
  2. On the View toolbar, click path ui icon view reset Reset All to show the rooftop view. Scroll the mouse wheel to zoom in and get a closer view. Move the viewpoint so that you are looking at the elevator doors.
  3. On the property panel, click Add. Set the Time to 0 and the Transition to Stationary as seen in Figure 24. This means we will hold the first view.
  4. Move the time slider to about 10 seconds.
  5. On the property panel, click Add. Set the Time to 10 and the Transition to Move to Next. This means at 10 seconds we will begin to move to the next keyframe.
  6. On the 3D view, drag to rotate down to the front face of the building with the stairs. Pan and zoom as necessary to capture the whole building inside the 3D view.
  7. Move the time slider to about 30 seconds.
  8. On the property panel, click Add. Set the Time to 30 and the Transition to Stationary. This means we will hold this view.
  9. Move the time slider to about 40 seconds.
  10. On the property panel, click Add. Set the Time to 40 and click Close to complete the tour. This is the end of the tour.
path ui dialog edit tour
Figure 24. Camera Tour Timeline.

To run the tour:

  1. Double-click Tour
  2. Move the time slider to 0 second
  3. Click Play.

You have successfully created and viewed a camera tour.

8.3. Create Movie

In this section, you will create a video file using the tour.

  1. On the 3D Results window on the Navigation panel, double-click the path ui icon camera tour Tour camera tour.
  2. On the Navigation panel, double-click the path ui icons contours Density contour plot.
  3. Move the time slider to 0 seconds.
  4. On the File menu, click Create Movie.
  5. Save the file as C:\Documents\Pathfinder\Getting Started\Fundamentals.wmv.
  6. On the Movie Properties dialog box click OK.
  7. Once the Movie Progress dialog box completes, the file should play in your default video player application.
path ui view results movie creation
Figure 25. Results Movie Creation.

You have successfully created a results movie.

9. Conclusion

Thank you for completing the Pathfinder Fundamentals tutorial. You should now have a basic understanding of the basics. There are still more advanced topics to cover. Refer to Pathfinder Tutorials for additional learning material.

To download the most recent version of Pathfinder, please visit the Pathfinder Support page and click the link for the current release. If you have any questions, please contact support@thunderheadeng.com

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