Custom collision from Blender 3D to Unreal Engine 4

Custom collision from Blender 3D to Unreal Engine 4

UCX from Blender 3D to Unreal Engine 4

This material is intended to help in the process of exporting & importing custom collisions. To correctly add and export custom collision from Blender 3D to Unreal Engine 4 it is important to keep some rules. But first of all we should start with question – Do I need collision for my asset?

Simplified collision geometry is important for optimizing collision detection in-game. Unreal Engine 4 provides basic tools for creating collision geometry within the Static Mesh Editor. Some circumstances, though, are best handled by creating custom collision geometry within your 3D modeling application and exporting it with the render mesh. Generally, this is true for any mesh with an opening or concave area that objects need to not collide with.

Unreal Engine

If you want your object to collide with other assets in your scene you need collision. Unreal Engine provide tools to add some basic collision shapes.

If you need more precise collision Use Complex Collision As Simple

However custom collision can give you more control over the creation process and performance.

Naming convention

To make Unreal Engine 4 to see our custom collision we need to name it correctly. Collision name must be same as object with “UCX_” prefix before the name.

For object “Cube” collision name = “UCX_Cube”

In case you would like to have more then just one collision, you can do it simply by adding “_01” numeration: “UCX_Cube_01”, “UCX_Cube_02”, “UCX_Cube_03” … See also example bellow.

Parenting

Parent your custom collision to the object.

  • In Outliner simply grab and drop “UCX_Cube” on the “Cube”, ( 2.79 )
  • or select as a first “UCX_Cube” next “Cube” and then Ctrl + P. ( 2.79, 2.80 )

Selecting

To export firstly select the collision next object and go to Files >> Export As >> FBX. If you want to make sure your FBX settings are right see also Export settings from Blender 3D to Unreal Engine 4

Single

Collision for Caves

This example with Pipe object is to illustrate process of Custom collision from Blender 3D to Unreal Engine 4 where you may need to use more than one collision to achieve the goal. In this case we want to have double sided collision.

For visual convenience you can set in Blender collision object to display as wireframe.

Collision do not need UV maps or materials, smoothing groups, vertex groups, shape keys, vertex colors, mark seems, etc.

Important:

  • Keep small gap between collision surfaces
  • Keep normals recalculated outside