Creating an OffMesh Link

OffMesh 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 OffMesh links.

We’re going to add an OffMesh 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 OffMesh 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 OffMesh Link set up! If the path via the OffMesh link is shorter than via walking along the Navmesh, the OffMesh 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 OffMesh 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 OffMesh 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 OffMesh Links Automatically for more details.

Further Reading

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