DeltaRoll - anyone?

Blitz3D Forums/Blitz3D Programming/DeltaRoll - anyone?

Boiled Sweets

(Posted 2007) [#1]

Can some clever person write a DeltaRoll function that actually works?

Blitz has built in DeltaYaw and DeltaPitch but no DeltaRoll function...

GfK	(Posted 2007) [#2]

DeltaPitch/Yaw tells you whether entity2 is below/above/left/right entity1.

What are you wanting "DeltaRoll" to do?

Boiled Sweets

(Posted 2007) [#3]

To turn a homing missile towards the player.

Any code examples would be VERY helpful!

GfK	(Posted 2007) [#4]

You can do that with DeltaPitch and DeltaYaw.

DeltaPitch tells you if the target is above (+) or below (-) the missile.

DeltaYaw is used to determine whether the target is to the left (-) or right (+) of the missile.

So for example, if DeltaYaw returns -10, you know that your missile needs to turn to the left. If DeltaPitch returns 40 then you need to increase the pitch of the missile.

If DeltaPitch and DeltaYaw were both 0, (which is not likely since they both return floats, but it keeps the explanation simple), then the missile is pointing directly at the target object.

Hope this helps.

[Edit] As for DeltaRoll - you don't need this. Just keep your EntityRoll for the missile at zero. Can do that with RotateEntity missile,EntityPitch(missile),EntityYaw(missile),0[,true]

Stevie G

(Posted 2007) [#5]

Best to stick with the deltayaw/ pitch functions but if you're missile moves in a similar way to Elite ships (i.e. Pitch and Roll only ) then here's a simple function I knocked up. Hit space to position the target randomly.

Stevie

Graphics3D 640,480,16,1

Global Camera = CreateCamera() : PositionEntity Camera, 0, 0, -30
Global Ship = CreateCone(): ScaleMesh Ship, 1, 2, 1 : EntityColor Ship, 0,0,255
Global Target = CreateCube() : EntityColor Target,255,0,0

Repeat

	If KeyHit( 57 )
		PositionEntity target, Rand(-20,20 ), Rand(-20,20 ), 10
	EndIf
	
	DR# = DELTAroll( Ship, Target )	
	TurnEntity ship, 0, 0, DR * .01
	
	RenderWorld()

	Text 0,0,DR
	
	Flip

Until KeyDown(1)

;=================================================================================
;=================================================================================
;=================================================================================

Function DELTAroll#( Source , Target )

	TFormPoint 0,0,0 , Target, Source
	Return VectorYaw ( TFormedX() , 0 , TFormedY() )

End Function

Stevie

Boiled Sweets

(Posted 2007) [#6]

Stevie G,

awesome!!!

one for the code archieves methinks...