Off screen targert pointer

Ok, i managed to knock together this:

It also works if the camera rolls, as you are translating the targets co-ords to the ships local co-ords. It seems to be pretty robust.

Graphics3D 800,600
SetBuffer BackBuffer()

Global camera = CreateCamera()

Global light = CreateLight()

Global ship = CreateSphere()
EntityParent camera,ship
PositionEntity camera,0,0,-10


Dim cubes(20)

For loop = 0 To 20

	cubes(loop) = CreateSphere(2)
	EntityColor cubes(loop),Rnd(50,255),Rnd(50,255),Rnd(50,255)
	PositionEntity cubes(loop),Rnd(-30,30),Rnd(-30,30),Rnd(-30,30)
	
Next


; set up the target and arrow pointer

Global target = CreateCube()
EntityColor target,200,40,40
PositionEntity target,10,3,20


Global arrow = CreateCone()

Global pivot = CreatePivot()

EntityParent arrow,pivot
PositionEntity arrow,0,4,0
ScaleEntity arrow,0.25,0.25,0.25
EntityColor arrow,40,40,200

EntityParent pivot,ship


While Not KeyHit(1)

	EntityColor target,Rnd(30,230),Rnd(30,230),Rnd(30,230)

	If KeyDown(203) Then RotateEntity ship,EntityPitch(ship,True),EntityYaw(ship,True)+1,EntityRoll(ship,True),True
	If KeyDown(205) Then RotateEntity ship,EntityPitch(ship,True),EntityYaw(ship,True)-1,EntityRoll(ship,True),True
	If KeyDown(200) Then RotateEntity ship,EntityPitch(ship,True)+1,EntityYaw(ship,True),EntityRoll(ship,True),True
	If KeyDown(208) Then RotateEntity ship,EntityPitch(ship,True)-1,EntityYaw(ship,True),EntityRoll(ship,True),True

	If MouseDown(1) Then MoveEntity ship,0,0,0.1
	If MouseDown(2) Then MoveEntity ship,0,0,-0.1
	
	
	; transform the targets X,Y,Z co-ords to the ships local co-ords
	TFormPoint EntityX(target,True),EntityY(target,True),EntityZ(target,True), 0, ship
	
	; work out the angle between the ship's local co-ords (0,0,0) and the targets tranformed co-ords
	angle = ATan2( TFormedY(), TFormedX())
	angle = angle - 90 ; adjust for blitz rotation system

	RotateEntity pivot,0,0,angle ; rotate the arrow pivot to point at the target.

	UpdateWorld
	RenderWorld
	Text 0,0," Arrow Keys to turn. Mouse button left to move forward and mouse button right to move backwards"
	Flip
	
Wend