Using gridmaps

Introduction

Gridmaps are a tool for creating 3D game levels, similar to the way TileMap works in 2D. You start with a predefined collection of 3D meshes (a MeshLibrary) that can be placed on a grid, as if you were building a level with an unlimited amount of Lego blocks.

Collisions and navigation can also be added to the meshes, just like you would do with the tiles of a tilemap.

Example project

To learn how GridMaps work, start by downloading the sample project: gridmap_demo.zip.

Unzip this project and add it to the Project Manager using the “Import” button.

Creating a MeshLibrary

To begin, you need a MeshLibrary, which is a collection of individual meshes that can be used in the gridmap. Open the “MeshLibrary_Source.tscn” scene to see an example of how to set up the mesh library.

../../_images/gridmap_meshlibrary1.png

As you can see, this scene has a Spatial node as its root, and a number of MeshInstance node children.

If you don’t need any physics in your scene, then you’re done. However, in most cases you’ll want to assign collision bodies to the meshes.

Collisions

You can manually assign a StaticBody and CollisionShape to each mesh. Alternatively, you can use the “Mesh” menu to automatically create the collision body based on the mesh data.

../../_images/gridmap_create_body.png

Note that a “Convex” collision body will work better for simple meshes. For more complex shapes, select “Create Trimesh Static Body”. Once each mesh has a physics body and collision shape assigned, your mesh library is ready to be used.

../../_images/gridmap_mesh_scene.png

Exporting the MeshLibrary

To export the library, click on Scene -> Convert To.. -> MeshLibrary.., and save it as a resource.

../../_images/gridmap_export.png

You can find an already exported MeshLibrary in the project named “MeshLibrary.tres”.

Using GridMap

Create a new scene and add a GridMap node. Add the mesh library by dragging the resource file from the FileSystem dock and dropping it in the “Theme” property in the Inspector.

../../_images/gridmap_main.png

The “Cell/Size” property should be set to the size of your meshes. You can leave it at the default value for the demo. Set the “Center Y” property to “Off”.

Now you can start designing the level by choosing a tile from the palette and placing it with Left-Click in the editor window. To remove a tile, use Shift+Right-click.

Click on the “GridMap” menu to see options and shortcuts. For example, pressing “S” rotates a tile around the y-axis.

../../_images/gridmap_menu.png

Holding <Shift> and dragging with the left mouse button will draw a selection box. You can duplicate or clear the selected area using the respective menu options.

../../_images/gridmap_select.png

In the menu, you can also change the axis you’re drawing on as well as shift the drawing plane higher or lower on its axis.

../../_images/gridmap_shift_axis.png

Using GridMap in code

See GridMap for details on the node’s methods and member variables.