Creating an Off-mesh Link

Off-Mesh Links are used to create paths crossing outside the walkable navigation meshThe main graphics primitive of Unity. Meshes make up a large part of your 3D worlds. Unity supports triangulated or Quadrangulated polygon meshes. Nurbs, Nurms, Subdiv surfaces must be converted to polygons. More info
See in Glossary surface. For example, jumping over a ditch or a fence, or opening a door before walking through it, can be all described as Off-mesh links.

We’re going to add an Off-Mesh Link component to describe a jump from the upper platform to the ground.

1. First create two cylinders: Game Object > 3D Object > cylinder.
2. You can scale the cylinders to (0.1, 0.5, 0.1) to make it easier to work with them.
3. Move the first cylinder at the edge of the top platform, close to the NavMeshA mesh that Unity generates to approximate the walkable areas and obstacles in your environment for path finding and AI-controlled navigation. More info
   See in Glossary surface.
4. Place the second cylinder on the ground, close to the NavMesh, at the location where the link should land.
5. Select the cylinder on the left and add an Off-Mesh Link component to it. Choose Add Component from the inspector and choose Navigation > Off Mesh Link.
6. Assign the leftmost cylinder in the Start field and rightmost cylinder in the End field.

Now you have functioning Off-Mesh Link set up! If the path via the off-mesh link is shorter than via walking along the Navmesh, the off-mesh link will be used.

You can use any game object in the sceneA Scene contains the environments and menus of your game. Think of each unique Scene file as a unique level. In each Scene, you place your environments, obstacles, and decorations, essentially designing and building your game in pieces. More info
See in Glossary to hold the Off-Mesh link component, for example a fence prefabAn asset type that allows you to store a GameObject complete with components and properties. The prefab acts as a template from which you can create new object instances in the scene. More info
See in Glossary could contain the off-mesh link component. Similarly you can use any game object with a Transform as the start and end marker.

The NavMesh bake process can detect and create common jump-across and drop-down links automatically. Take a look at the Building Off-Mesh Links Automatically for more details.

Further Reading

• Building Off-Mesh Links Automatically - learn how to automatically build Off-Mesh Links.
• Navigation HowTos - common use cases for NavMesh Agent, with source code.
• Off-Mesh Link component reference – full description of all the Off-Mesh Link properties.
• Off-Mesh Link scripting reference - full description of the Off-Mesh Link scripting API.