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query - query handle index - one-based hit index |
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Returns the mesh or height-field triangle index of a hit, or -1. Returns the zero-based native mesh/height-field triangle index for a ray or sweep hit, or -1 if unavailable/not applicable. It is separate from the owning shape and compound child index. Overlap queries return -1. This identifies cooked native geometry; it is not necessarily an index into the source Blitz mesh after cooking. Results are copied. They survive StepPhysics and other queries until this query runs successfully again or is freed. Failed runs preserve the previous results. Freeing the owning world frees its queries. Invalid/stale/wrong-kind handles and invalid hit indices raise runtime errors. See also: CreatePhysicsQuery, PhysicsQueryFilter, PhysicsQueryTarget, QueryPhysicsRay, QueryPhysicsSphere, PhysicsQueryLimit. |
; PhysicsQueryTriangle Example
; ----------------------------
Graphics3D 640,480,0,2
SetBuffer BackBuffer()
Const PHYSICS_STATIC=0
Const PHYSICS_DYNAMIC=2
camera=CreateCamera()
PositionEntity camera,0,3,-7
RotateEntity camera,20,0,0
light=CreateLight()
RotateEntity light,45,-30,0
AmbientLight 60,60,60
; An independent Box3D world with standard gravity
world=CreatePhysicsWorld()
; Blue static floor
ground=CreateCube()
ScaleEntity ground,6,0.5,6
PositionEntity ground,0,-0.5,0
EntityColor ground,80,160,255
ground_body=CreatePhysicsBody(world,ground,PHYSICS_STATIC)
ground_shape=PhysicsBodyBox(ground_body,12,1,12)
; A static mesh ramp made of 8 strips, each strip two triangles
ramp=CreateMesh()
surface=CreateSurface(ramp)
For strip=0 To 7
x#=strip-4
AddVertex surface,x,1.6-strip*0.2,-1.5
AddVertex surface,x,1.6-strip*0.2,1.5
AddVertex surface,x+1,1.4-strip*0.2,-1.5
AddVertex surface,x+1,1.4-strip*0.2,1.5
AddTriangle surface,strip*4,strip*4+1,strip*4+3
AddTriangle surface,strip*4,strip*4+3,strip*4+2
Next
UpdateNormals ramp
EntityFX ramp,2
ramp_body=CreatePhysicsBody(world,ramp,PHYSICS_STATIC)
ramp_shape=PhysicsBodyMesh(ramp_body,ramp)
; Slot 2 of the ramp's material table is ice, with no friction
PhysicsShapeMaterials ramp_shape,2
PhysicsShapeMaterialFriction ramp_shape,2,0
; A yellow probe you move along the ramp with A and D
probe=CreateSphere(8)
ScaleEntity probe,0.15,0.15,0.15
EntityColor probe,255,230,60
PositionEntity probe,0,3,-1
query=CreatePhysicsQuery(world)
; Crates resting on the grippy ramp
Dim crate_bodies(3)
For i=0 To 3
crate=CreateCube()
ScaleEntity crate,0.3,0.3,0.3
EntityColor crate,255,120,70
crate_bodies(i)=CreatePhysicsBody(world,crate,PHYSICS_DYNAMIC)
crate_shape=PhysicsBodyBox(crate_bodies(i),0.6,0.6,0.6)
ResetPhysicsBody crate_bodies(i),-3.5+i*2,2-i*0.4,0,0,0,-0.2
Next
PaintStrips(ramp,painted)
While Not KeyDown(1)
; Space paints the next strip as ice, so the crates slide
If KeyHit(57) And painted<8
PhysicsMeshTriangleMaterial ramp_shape,painted*2,2,2
painted=painted+1
PaintStrips(ramp,painted)
EndIf
; A and D move the probe, and a ray looks straight down from it
If KeyDown(30) Then MoveEntity probe,-0.05,0,0
If KeyDown(32) Then MoveEntity probe,0.05,0,0
StepPhysics world,1.0/60.0,4
hits=QueryPhysicsRay(query,EntityX(probe),3,EntityZ(probe),0,-4,0)
; Arrow keys move the camera
If KeyDown(200) Then MoveEntity camera,0,0,0.1
If KeyDown(208) Then MoveEntity camera,0,0,-0.1
If KeyDown(203) Then TurnEntity camera,0,1,0
If KeyDown(205) Then TurnEntity camera,0,-1,0
RenderWorld
Text 0,0,"Arrow keys: move camera Space: paint ice A / D: move the probe Esc: exit"
If hits>0 Then Text 0,20,"PhysicsQueryTriangle(query,1) = "+PhysicsQueryTriangle(query,1)+" (strip "+PhysicsQueryTriangle(query,1)/2+")"
Flip
Wend
FreePhysicsWorld world
End
Function PaintStrips(ramp,painted)
; Ice strips are pale blue, grippy strips are green
surface=GetSurface(ramp,1)
For v=0 To CountVertices(surface)-1
If v/4<painted
VertexColor surface,v,200,230,255
Else
VertexColor surface,v,120,200,140
EndIf
Next
End Function