How do I set up Navmeshes for characters of different sizes?

Development Character & Animation
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5

The Nav Agent System doesn’t work the way you would expect it to, and you can’t specify which Agent AI characters use. The best workaround I’ve found is the following:

  1. Right-click in your content browser and create a new blueprint actor of “NavArea” type. Give it a descriptive name for the AI you want to use it like “NPC_XYZ_Area”

  2. Create another BP actor - search for “Nav Filter” in the class search and select “NavFilter_AIControllerDefault”. Give it a descriptive name like “NPC_XYZ_NavFilter”. Open this and add a new array element by clicking on the +. For the AreaClass give it your custom AreaClass you created in step 1. FYI it might not show in the list, but if you select it in the Content Browser and use the Arrow to force it in, it will work.

  3. Open the AIController for your NPC and search for “Nav” in the class defaults. Under Default Navigation Filter Class specify your NavFilter you created in Step 2.

  4. In your level, add a Nav Modifier volume (or several), set it to whatever size you want to make sure that your NPC will fit in the area you place it (IE make it narrow if you want your AI to avoid walking into walls, buildings etc.), and then set its Area Class to match the area class you created in step 1.

  5. Watch as your AI moves only on these volumes and forget about the stupid Navigation Agents system that we can’t control.

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