| Home Page | Recent Changes | Preferences


UT2003 :: Object >> Actor (Property Group: Collision)

Properties that control how an actor blocks other actors. For the UT version, see Actor (UT)/Collision.

The difference between Blocking and Colliding is that Colliding actors only get a Touch() event when another object collides with it; Blocking actors also prevent the other object from moving to that location. Actors can be made to do none, either, or both.

bool bAutoAlignToTerrain
Auto-align to terrain in the editor
bool bBlockActors
Blocks other nonplayer actors.
bool bBlockKarma
Block actors being simulated with Karma.
bool bBlockNonZeroExtentTraces
Blocks actors with CollisionRadius and CollisionHeight greater zero. Also traces that use the Extent parameter will hit this actor.
bool bBlockPlayers
Blocks other player actors.
bool bBlockZeroExtentTraces
Blocks actors with CollisionRadius and CollisionHeight set to zero. Also traces that don't use the Extent parameter will hit this actor.
bool bCollideActors
Collides with other actors.
bool bCollideWorld
Collides with the world.
bool PathColliding
Nytro: I think this means that bot paths wont't be affected by its collision. I'll test that soon.
bool bProjTarget
Projectiles should potentially target this actor.
bool bUseCylinderCollision
use a collision cylinder, set the size with the next two properties
float CollisionHeight
Half-height of the collision cylinder
float CollisionRadius
Radius of the collision cylinder
ESurfaceTypes SurfaceType


So, the above is great, but what do I need to set to get ...

  • a Static mesh that doesn't block players
  • one that has no collision overhead

Tarquin: Dumb question, but if you set bUseCylinderCollision to false, what determines where the actor collides?

MythOpus: I believe Karma makes collisions on it's own using the polygons in the model but if that is turned of (I forget what property) then I don't think an actor will collide with it.

Related topics

  • OCD – Technical lowdown of object collision detection.
  • Collision
  • Actor Overview – More on working with Actors, adding actors to a map and setting properties.

The Unreal Engine Documentation Site

Wiki Community

Topic Categories

Image Uploads

Random Page

Recent Changes

Offline Wiki

Unreal Engine

Console Commands


Mapping Topics

Mapping Lessons

UnrealEd Interface


Scripting Topics

Scripting Lessons

Making Mods

Class Tree


Modeling Topics


Log In