Single Agent Grid Search

Follow these steps to visualise a single-agent search, in our case A*, on a grid map.

warning

This tutorial was written for version v1.0.9.

Prepare the Map

We support grid maps as .grid files. A .grid file is a text file that looks like this:

cross.grid

type octile
height 5
width 5
map
.....
..@..
.@@@.
..@..
.....

Save this file as cross.grid to your system.

Load the Map

• In the Layer panel, click + Layer to add a new layer.
• Click the pencil icon to edit the layer.
• For Type, choose Map.
• For Source, choose Import Map, then pick cross.grid from your system.
• Close the Edit Layer modal.
• In the Viewport panel, click Fit to fit the map to the viewport.

This should be the result:

Prepare the Search Trace

You can generate the search trace in a number of ways depending on your solver.

Demo Search Trace

Download this pre-computed search trace.

The file should start like this:

example.trace.yaml

render:
  components:
    tile:
      - $: rect
        width: 1
        height: 1
        x: "{{$.event.x}}"
        y: "{{$.event.y}}"
        fill: "{{$.color[$.event.type]}}"
  views:
    main:
      components:
        - $: tile
  path:
    pivot:
      x: "{{$.event.x + 0.5}}"
      y: "{{$.event.y + 0.5}}"
    scale: 0.3
events:
  - type: source
    id: 96
    x: 0
    y: 0
  - type: destination
    id: 228
    x: 4
    y: 4

The search trace contains a record of the events that occured during the search and how to visualise them.

Load the Search Trace

• In the Layer panel, click + Layer to add a new layer.
• Click the pencil icon to edit the layer.
• For Type, choose Trace.
• For Trace, choose Choose File, then pick the search trace from your system.
• Close the Edit Layer modal.
• In the Viewport panel, click Fit to fit the map to the viewport.

Warthog

TODO: explain on how warthog can be download and used through the terminal and produce a search trace

Query

By default, Visualiser is bundled with a WebAssembly version of Warthog, a solver for grid maps.

Check that Warthog (WebAssembly) is enabled in the Settings panel, in the Connections tab.

Adding the Query

• In the Layer panel, click + Layer to add a new layer.
• Click the pencil icon to edit the layer.
• For Type, choose Query.
• For Algorithm, choose the algorithm that you want to visualise.
• For Map, choose a map that you have chose.
• Close the Edit Layer modal.

Adding Source and Destination

• Left click on any part of the map that you wanted to be set as a source, then Set as Source
• Do the same for the destination click Set as Destination
• A green pixel will show up marking the source

A demonstration on how to add a query, destination and source is provided in this Video

Step through the Search Trace

• In the Steps panel, choose the search trace layer from the layer dropdown. Here, the layer is named Cross Example.
• Click Play.

 

A demonstration on how to import a map and a trace is provided in this Video  

You have now visualised an A* search on a grid map.