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entity - entity handle collision_type - collision type number, in the range 0-999. 0 removes the entity from collision checking, and is what every new entity starts with recursive (optional) - true to apply the collision type to the entity's children too; false (default) |
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Sets the collision type of an entity - which collision rules apply to it. Collision types are just numbers you invent to group your entities: say type 1 for the player, 2 for enemies, 3 for scenery. The Collisions command then declares which types collide with which, and UpdateWorld does the checking. An entity with type 0 (the default) takes no part in collisions at all. Setting a type also resets the entity's collision state, exactly like ResetEntity: the entity is treated as freshly placed at its current position, so no collision fires against anything it has just moved through. Handy when teleporting; surprising if you change types mid-fall. With recursive set to true the type is applied to the entity and every descendant - useful for making a whole loaded model hierarchy solid in one call. See also: GetEntityType, Collisions, EntityRadius, EntityBox, ResetEntity. |
Entity physics (Extended): the same type IDs select symmetric Physics pairs. A label does not enroll an entity; use EntityPhysics or an existing Collisions participation rule. Type 0 has no pair interactions, but an enrolled free dynamic body still receives gravity. Changing type refilters contacts and clears affected collision history while retaining its body, joints and dynamic velocity.
; EntityType Example
; ------------------
Graphics3D 640,480,0,2
SetBuffer BackBuffer()
; Collision type ids
type_player=1
type_scenery=2
; NOTE: fixed overhead camera - the arrow keys steer the PLAYER, not the camera
camera=CreateCamera()
PositionEntity camera,0,13,-13
RotateEntity camera,45,0,0
light=CreateLight()
RotateEntity light,60,30,0
floor=CreatePlane()
EntityColor floor,70,110,70
; The player ball is the collision SOURCE, so it needs an ellipsoid radius
player=CreateSphere()
EntityColor player,220,60,60
PositionEntity player,0,1,0
EntityRadius player,1
; The star of the show: give the ball its collision type
EntityType player,type_player
; A wall whose collision type we will toggle, plus a crate that stays solid
wall=CreateCube()
ScaleEntity wall,7,1.5,0.5
PositionEntity wall,0,1.5,7
EntityColor wall,150,150,160
EntityType wall,type_scenery
crate=CreateCube()
ScaleEntity crate,1.2,1.2,1.2
PositionEntity crate,-4,1.2,3
EntityColor crate,200,160,60
EntityType crate,type_scenery
; Ellipsoid-to-polygon collisions with a sliding response
Collisions type_player,type_scenery,2,2
While Not KeyDown(1)
; Arrow keys steer the player ball
If KeyDown(200) Then MoveEntity player,0,0,0.1
If KeyDown(208) Then MoveEntity player,0,0,-0.1
If KeyDown(203) Then MoveEntity player,-0.1,0,0
If KeyDown(205) Then MoveEntity player,0.1,0,0
; Space toggles the wall's collision type between type_scenery and 0.
; Type 0 means the wall is ignored by all collision checking.
If KeyHit(57)
If GetEntityType(wall)=0
EntityType wall,type_scenery
EntityAlpha wall,1
Else
EntityType wall,0
EntityAlpha wall,0.4
EndIf
EndIf
; UpdateWorld performs the collision checks and the slide response
UpdateWorld
RenderWorld
Text 0,0,"Arrow keys: drive the ball Space: toggle the wall's type Esc: exit"
Text 0,20,"EntityType wall,"+GetEntityType(wall)+" (0 = no collision checking)"
Text 0,40,"Set it to 0 and the ball drives straight through the ghost wall"
Flip
Wend
End