Pathfinder Fundamentals
Reading Time: 18 minutes1. 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
- Download and install the latest version of Pathfinder from the Pathfinder Support page.
- If you haven’t already, sign up for a free 30-day trial license or purchase a license.
- 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.
- Download the Pathfinder Fundamentals zip file.
- Open Windows Explorer and browse to the downloaded file.
- Right-click
pathfinder-fundamentals.zip
and click Extract All. - From the extracted folder, open
Fundamentals.pth
to launch Pathfinder with that model. - Review the interface elements as shown in Figure 1. These will be often referred to throughout this series.
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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.
On the View toolbar, click
Switch to the Perspective View.
- On the View toolbar, click
3D Orbit Navigation.
- Drag the mouse to rotate the camera.
- Hold down Shift while dragging the mouse to pan the camera.
- Rotate the mouse wheel, or hold down Alt while dragging the mouse, to zoom the camera.
On the View toolbar, click
Switch to the Top View.
- On the View toolbar, click
Select/Edit Objects.
- Hold down the left mouse button and drag to select objects.
- Hold down the right mouse button and drag to pan the camera.
- Rotate the mouse wheel to zoom the camera.
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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.
- On the View toolbar, click
Switch to the Perspective View.
- On the Navigation panel on the Floor list, select
Floor 0.0 ft to show only its objects.
- On the Navigation panel, right-click
Floor 10.0 ft and click Show to add its objects to the current view.
- On the 3D view, right-click any object and click Hide to remove it from the current view.
- On the 3D view, right-click any empty space and click Show All to bring all objects back into the current view.
- On the Navigation panel, select
Auto Expand Selection.
- On the 3D view, click any object. The Navigation panel expands and highlights the matching object in the list.
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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.
On the Main toolbar, click Run Simulation.
- On the Results window, click Run. The simulation will play until all occupants have exited the model, and should appear similar to Figure 4.
- On the Playback toolbar, click Increase Speed to play the results two times faster than real time.
- Close the Results window and the Run Simulation dialog box.
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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.
- On the Main toolbar, click
New Model. If prompted by the Save Changes dialog box, click No.
- On the Main toolbar, select
Show values in EN units.
- On the Main toolbar, click
Save model.
- Create a new folder named
Getting Started
, and name the filemyFundamentals.pth
.
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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.
- On the Main toolbar and click
Import File.
- Navigate to the
Pathfinder-Fundamentals
folder extracted frompathfinder-fundamentals.zip
and openpathfinder-fundamentals.dwg
. - On the Import dialog box, select Into the current model and click Next.
- Select mm as the file’s length unit and click Next.
- 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. - Use the default import settings and click Next.
- Click Finish to import the file.
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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.
- On the Draw toolbar, click
Extract Floor from Imported Geometry.
- On the 3D view, click anywhere on the surface of the first floor.
- On the View toolbar, clear
Show Imported Geometry.
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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.
On the Draw toolbar, double-click
Add a New Door.
- On the property panel in the Max Width box, type
60 in
. On the property panel in the Max Depth box, type
10 in
. Press Enter to set the value.
- 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.
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- Repeat step 5 for each of the 11 doorways. The individual rooms of the first floor are automatically created as the doors are added.
- On the 3D view, point to a corner of the outer grounds. Drag to an adjacent corner.
- Repeat step 7 for the other three sides of the outer grounds.
- Press Esc once all doors have been created to close the door tool.
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5.4. Create Occupants
In this section, you will add occupants to the rooms.
- On the Navigation panel, select
Floor 0.0 ft.
- On the 3D view, hold down Ctrl and click the elevator rooms and the outdoor floor to unselect.
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- On the 3D view, right-click any selected area and click Add Occupants.
- 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.
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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.
- At the top of the Navigation panel, in the Floor list dropdown, select Add New.
- On the New Floor dialog box in the Enter Floor Location box, type
10 ft
and click OK. - Repeat steps 1 - 2 for each floor until you have created
Floor 60.0 ft.
- On the View toolbar, select
Show Imported Geometry.
At the top of the Navigation panel, in the Floor list dropdown box, select
Floor 10.0 ft.
- On the 3D view, right-click the Floor 10.0 ft ceiling and click Hide.
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- On the Draw toolbar, click
Extract Floor from Imported Geometry.
- On the 3D view, click anywhere on Floor 10.0 ft.
- On the View toolbar, clear
Show Imported Geometry.
- Hide the imported geometry and then add nine doors, similar to Floor 0.0 ft in Section 5.4, excluding the elevator room doors.
- On the Navigation panel, right-click
Floor 10.0 ft and click Add Occupants.
- In the Add Occupants dialog box, enter "Floor 2" for the Group Name and in the By Number box, type
100
and click OK.
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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.
- On the Navigation panel, expand the Occupants list.
- On the Navigation panel, select
Floor 10.0 ft. Hold down the control key and select the "Floor 2" occupant group.
- On the Draw toolbar, click
Copy/Move Objects.
- On the property panel, select Copy Mode.
- On the property panel in the Copies box, type
4
. - On the property panel in the Move Z box, type
10 ft
. On the property panel, click Copy/Move.
- On the Navigation panel, select each copied occupant group. Right click any of the selected items and click Rename… to open the Rename dialog.
- 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.
- On the Navigation panel, right-click
Floors and click Show.
- On the View toolbar, select
Show Imported Geometry.
- On the Draw toolbar, click
Extract Floor from Imported Geometry.
- On the 3D view, click anywhere on the rooftop floor.
- On the Navigation panel, right-click
Floor 60.0 ft and click Add Occupants.
- 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.
- On the Navigation panel in the Floor list, select Show All.
- On the View toolbar, select
Show Imported Geometry.
- On the Draw toolbar, click
Extract Floor from Imported Geometry
- On the 3D view, click anywhere on the landing connected to the four stairs.
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- On the View toolbar, clear
Show Imported Geometry.
- On the Draw toolbar, click
Create stairs between two edges by choosing a point on each.
For one of the four stairs connected to the bottom landing, click a point along the bottom and top edge to create the stairs.
- Repeat steps 6 - 7 for the other three stairs connected to the bottom landing.
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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.
- On the 3D view, hold down Ctrl while clicking the four stairs and the landing.
- On the Draw toolbar, click
Copy/Move Objects.
- On the property panel, select Copy Mode.
- On the property panel in the Copies box, type
5
. - On the property panel in the Move Z box, type
10 ft
. - On the property panel, click Copy/Move.
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6.5. Create Elevators
In this section, you will create elevators. This will complete the model’s geometry.
- On the Navigation panel in the Floor list, select
Floor 0.0 ft.
- On the View toolbar, clear
Show Imported Geometry.
- On the 3D view, right-click one of the two elevator rooms and click Create Elevator.
- On the New Elevator dialog box, click OK.
- Repeat steps 3-4 for the other elevator room.
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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.
- On the Navigation panel in the Floor list, select Show All.
- Expand the
Occupants list.
- On the Navigation panel, select the Floor 1 occupant group.
- On the property panel, select Color, and click the color box.
On the Color dialog box in the Color Code box, type
FF2222
, and click OK.- 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.
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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.
- On the Navigation panel, right-click
Behaviors and click New Behavior.
- On the New Behavior dialog box in the Name box, type Elevator and click OK.
- On the property panel, select
Goto Elevators from the Add Action list.
- On the property panel, click Create.
- On the Navigation panel, right-click the
Floor 3 occupant group and click Properties.
- On the Edit Selected Occupants dialog box, click the Behavior link.
- On the Behavior dialog box, enter
10
next to the Elevator behavior and enter90
next to the Goto Any Exit behavior. - Click OK on both dialog boxes.
- Repeat steps 5 - 8 for the Floor 4 and Floor 5 occupant groups.
Use
20
and80
as the Elevator and Goto Any Exit distribution percentages. - Repeat steps 5 - 8 for the Floor 6 and Rooftop occupant groups.
Use
30
and70
as the Elevator and Goto Any Exit distribution percentages.
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7.2. Create Profiles
In this section you will create occupant profiles so that each individual occupant has different characteristics.
- On the Navigation panel, right-click
Profiles and click Add a Profile.
- On the New Profile dialog box in the Name box, type Office and click OK.
- on the Navigation panel, right-click the new created Office profile and click Properties.
- On the Edit Profiles dialog box on the 3D Model box, click the list of models.
- On the 3D Model dialog box, select models that represent a typical office environment and click OK.
- On the Edit Profiles dialog box on the Characteristics tab in the Speed list, select Uniform.
- In the Speed list, click Edit to open the Uniform Distribution dialog box.
- On the Uniform Distribution dialog box in the Min box, type
2.0
. - On the Uniform Distribution dialog box in the Max box, type
4.3
and click OK. - On the Edit Profiles dialog box, click Apply.
- On the Edit Profiles dialog box, click New.
- 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. - On the Edit Profiles dialog box, select Default and click Delete.
On the Remove dialog box, click Yes. On the Profile in Use dialog box on the Replace with box, select Office and click OK.
Figure 20. The Profiles are Ready to be Assigned. - On the Edit Profiles dialog box, click OK.
- On the Navigation panel, right-click the
Rooftop occupant group and click Properties.
- On the Edit Selected Occupants dialog box, click the Profile link.
- On the Profile dialog box in the Rooftop box, click Distribute Evenly and click OK.
- On the Edit Group Distributions dialog box, click OK.
- Repeat steps 14 - 17 for
Floor 5 -
Floor 6 and assign 100% of the occupants the Apartment profile.
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8. Analyze Results
In this section and its subsections, you will compile a simulation, explore the post-processing options, and create a video report.
- On the Main toolbar, click
Run Simulation.
- Close the Run Simulation dialog box when the simulation is finished running.
- On the Main toolbar, click
View Room Usage.
- 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.
- Close the Occupant Counts window.
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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:
- On the Main toolbar, click
View 3D Results.
- On the 3D Results window on the Navigation panel, double-click the
Time to Exit contour plot.
- On the Optimize Contour dialog box, click Yes.
- Once the Generating Occupant Contour dialog box has completed, click
Play to view the results with the contour overlay.
- On the Navigation panel, right-click the
Time to Exit contour plot and click Properties.
- On the Time to Exit Properties dialog box, in the Opacity Source dropdown, select feather below.
- In the Feather Threshold box below the Opacity Source dropdown, type
1
and click OK.
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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.
- In the Results view, on the Navigation panel right-click
Views and click New Tour.
- On the View toolbar, click
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.
- 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. - Move the time slider to about 10 seconds.
- 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. - 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.
- Move the time slider to about 30 seconds.
- On the property panel, click Add.
Set the Time to
30
and the Transition to Stationary. This means we will hold this view. - Move the time slider to about 40 seconds.
- 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.
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To run the tour:
- Double-click Tour
- Move the time slider to 0 second
- 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.
- On the 3D Results window on the Navigation panel, double-click the
Tour camera tour.
- On the Navigation panel, double-click the
Density contour plot.
- Move the time slider to 0 seconds.
- On the File menu, click Create Movie.
- Save the file as
C:\Documents\Pathfinder\Getting Started\Fundamentals.wmv
. - On the Movie Properties dialog box click OK.
- Once the Movie Progress dialog box completes, the file should play in your default video player application.
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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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