Offscreen Tracking

Blitz3D Forums/Blitz3D Beginners Area/Offscreen Tracking

SilverCoin

(Posted 2009) [#1]

Hi guys, I'm new here and this is my first post! :-D

I'm trying to create a simple soccer game. The camera is focused on the location of the ball, and sometimes it gets to a spot where there are no user-controlled players are. So I need a system that tracks where the user-controlled players are offscreen. I'm sure you guys have some idea about this, you know those little arrows at the edge of the screen pointing the relative position of player?

I have no idea how to do this, and CameraProject seems to only work for objects onscreen. Any help?

Thanks a lot in advance!

AJ00200

(Posted 2009) [#2]

You can use some simple if < and > commands. This is English programming below:

if player is behind camera by 1, put and arrow here
if player is behind camera by 2, put and arrow here
...

AJ00200

Nate the Great

(Posted 2009) [#3]

you could have an arrow that points at the player... basic example

Graphics3D 640,480,0,2
HidePointer()
cam = CreateCamera()
TurnEntity cam,30,0,0


pointer = CreateSphere()
PositionMesh pointer,0,1,0
MoveEntity pointer,0,-4,10
ScaleEntity pointer,1,.1,2
RotateMesh pointer,90,0,0

sphere = CreateSphere()

plane = CreatePlane()
MoveEntity plane,0,-5,0
EntityColor plane,0,0,255
EntityAlpha plane,.5
mir = CreateMirror()
MoveEntity mir,0,-5,0

lit = CreateLight()
TurnEntity lit,90,0,0

SetBuffer BackBuffer()

While Not KeyDown(1)
Cls
PointEntity pointer,sphere
PositionEntity sphere,(MouseX()-320)/20.0,-4,(-MouseY()/40.0) + 9

UpdateWorld()
RenderWorld()

Flip
Wend
End

SilverCoin

(Posted 2009) [#4]

Hey thanks a lot guys! You're idea was great Nate, I'll try it out!

Nate the Great

(Posted 2009) [#5]

ok thanks... I know what you were originally trying to do but I cant figure that out either :p but many popular games use an arrow that points at the player as well so im sure it will be fine

AJ00200

(Posted 2009) [#6]

Your going to need to do some basic Trig. Use the atan() function to find the angle. Atan(distance away from screen edge X /distance away Y) Add that to the sides angle (top=0, right=90, bottom=180, left=270) and that will give you the angle.

Can anyone explain this better??

AJ00200

(Posted 2009) [#7]

Maybee its normal tan()

Andy	(Posted 2009) [#8]

Didn't the 'camera' in 'Kick off' just follow the player closest to the ball?