There are a large number of properties and settings in the Collision Presets/Collision Response section of the Collision Properties category, so they've been separated out for clarity.
Properties
Below are the properties for the Collision Presets, a sub-category in the Collision Properties on Physics Bodies (BodyInstances).
Collision Presets
Property
Description
Collision Presets
The default collision profiles and any you have created in Project Settings -> Engine -> Collision -> Preset (see: Add a Custom Object Type to Your Project for information on creating custom collision profiles), will appear here.
Property
Description
Default
Use the settings that were applied to the Static Mesh in the Static Mesh Editor.
Custom...
Set all custom collision settings for this instance.
NoCollision
No Collision.
BlockAll
WorldStatic object that blocks all actors by default. All new custom channels will use its own default response.
OverlapAll
WorldStatic object that overlaps all actors by default. All new custom channels will use its own default response.
BlockAllDynamic
WorldDynamic object that blocks all actors by default. All new custom channels will use its own default response.
OverlapAllDynamic
WorldDynamic object that overlaps all actors by default. All new custom channels will use its own default response.
IngoreOnlyPawn
WorldDynamic object that ignores Pawn and Vehicle. All other channels will be set to default.
OverlapOnlyPawn
WorldDynamic object that overlaps Pawn, Camera, and Vehicle. All other channels will be set to default.
Pawn
Pawn object. Can be used for capsule of any playable character or AI.
Spectator
Pawn object that ignores all other actors except WorldStatic.
CharacterMesh
Pawn object that is used for Character Mesh. All other channels will be set to default.
PhysicsActor
Simulating actors.
Destructible
Destructible actors.
InvisibleWall
WorldStatic object that is invisible.
InvisibleWallDynamic
WorldDynamic object that is invisible.
Trigger
WorldDynamic object that is used for trigger. All other channels will be set to default.
Ragdoll
Simulating Skeletal Mesh Component. All other channels will be set to default.
Vehicle
Vehicle object that blocks Vehicle, WorldStatic, and WorldDynamic. All other channels will be set to default.
UI
WorldStatic object that overlaps all actors by default. All new custom channels will use its own default response.
Collision Enabled
Collision Enabled can have 4 possible states as listed below.
Property
Description
No Collision
This body Will have no representation in the physics engine. It cannot be used for spatial queries (raycasts, sweeps, overlaps) or simulation (rigid body, constraints). This setting gives the best performance possible, especially for moving objects.
Query Only
This body is used only for spatial queries (raycasts, sweeps, and overlaps). It cannot be used for simulation (rigid body, constraints). This setting is useful for character movement and objects that do not need physical simulation. Some performance gains are made by reducing the data in the physics simulation tree.
Physics Only
This body is only for physics simulation (rigid body, constraints). It cannot be used for spatial queries (raycasts, sweeps, overlaps). This setting is useful for simulated secondary motion on characters that do not need per bone detection. Some performance gains are made by reducing the data in the query tree.
Collision Enabled
This body can be used for both spatial queries (raycasts, sweeps, overlaps) and simulation (rigid body, constraints).
Object Type
Property
Description
WorldStatic
This should be used for any Actor that doesn't move. Static Mesh Actors are a good example of an Actor that will probably have a WorldStatic type.
WorldDynamic
WorldDynamic is for Actor types that will be moving under the influence of animation or code; kinematic. Lifts and doors are good examples of WorldDynamic Actors.
Pawn
Any player controlled entity should have the Pawn type. The player's character is a good example of an Actor that should receive the Pawn Object Type.
PhysicsBody
Any Actor that will be moving due to the physics simulation.
Vehicle
Vehicles receive this type by default.
Destructible
Destructible Meshes receive this by default.
Collision Responses
These define how this Physics Body should interact with all of the other types of Trace and Object Types. Remember, it's the interaction between both Physics Bodies that define the resulting action, so the Object Type and Collision Responses of both Physics Bodies matter.
Response
Description
Ignore
Regardless of the Collision Response of the other Physics Body, this Physics Body will ignore the interaction.
Overlap
If the other Physics Body is set to Overlap or Block this Physics Body's Object Type, an Overlap Event can occur.
Block
If the other Physics Body is set to Block this Physics Body's Object Type, a Hit Event can occur.
Trace Responses
Trace responses are used in Traces (ray casts), such as the Blueprint Node Line Trace by Channel.
Property
Description
Visibility
General visibility testing channel.
Camera
Usually used when tracing from the camera to something.
Object Responses
Property
Description
WorldStatic
How this Physics Body should react when interaction with a WorldStatic Physics Body Object Type.
WorldDynamic
How this Physics Body should react when interaction with a WorldDynamic Physics Body Object Type.
Pawn
How this Physics Body should react when interaction with a Pawn Physics Body Object Type.
PhysicsBody
How this Physics Body should react when interaction with a PhysicsBody Physics Body Object Type.
Vehicle
How this Physics Body should react when interaction with a Vehicle Physics Body Object Type.
Destructible
How this Physics Body should react when interaction with a Destructible Physics Body Object Type.
