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entity = handle of Loaded or Created Entity
global = True for Global coordinates, False for Local. Optional, defaults to False. |
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The X-coordinate of the entity.
If the global flag is set to False then the parent's local coordinate system is used. NOTE: If the entity has no parent then local and global coordinates are the same. In this case you can think of the 3d world as the parent. Global coordinates refer to the 3d world. Blitz 3D uses a left-handed system: X+ is to the right Y+ is up Z+ is forward ( into the screen ) Every entity also has its own Local coordinate system. The global system never changes. But the local system is carried along as an entity moves and turns. This same concept is used in the entity movement commands: MoveEntity entity, 0,0,1 No matter what the orientation this moves one unit forward. |
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; EntityX / EntityY / EntityZ example.
; Escape quits, other keys move or pause the display. Const width = 640, height = 480 Const KEY_ESC = 1, KEY_LEFT = 203, KEY_RIGHT = 205 Graphics3D 640, 480 AmbientLight 50, 50, 50 Global isMoving = False ; used to pause/resume movement Global count ; how many updates have been done ; Set up a camera, light and three entities... cam = CreateCamera() PositionEntity cam, 0, 2, -50 CameraZoom cam, 4 lt = CreateLight() : TurnEntity lt, 30, 40, 0 Global oSphere, pCone, cSphere oSphere = CreateSphere() EntityColor oSphere, 250, 50, 0 ; Orange = Origin, parent of cone pCone = CreateCone( 8, True, oSphere) ; will be a parent of small sphere ScaleEntity pCone, .8, 2.0, .8 PositionEntity pCone, 8, 0, 0 EntityColor pCone, 255, 255, 0 cSphere = CreateSphere( 8, pCone ) ; child of the cone EntityColor cSphere, 150, 150, 0 ScaleEntity cSphere, .4/.8, .4/2.0, .4/.8 ; try commenting out this line PositionEntity cSphere, 0, 2, 0 ; above parent ; ... and we are ready run. While Not KeyDown( KEY_ESC ) UpdateEverything RenderWorld ShowInfo Flip Wend End Function UpdateEverything( ) ; Nothing moves relative to its parent, so local coordinates are constant. ; Try uncommenting the PositionEntity command to change this. If GetKey() Then isMoving = Not isMoving If isMoving TurnEntity oSphere, 0, .5, 0 TurnEntity pCone, .2, 0, 0 count = count + 1 a# = count Mod 360 ; PositionEntity cSphere, 0, 2 + Sin( a ), 0 ; experiment with this End If End Function Function ShowInfo( ) ; global and local coordinates for all entities Local x$, y$, z$ Color 255, 255, 255 Text 185, 20, "Global" Text 495, 20, "Local" Color 250, 50, 0 Text 20, 50, "oSphere: " + XYZ( oSphere, True ) Text 400, 50, XYZ( oSphere, False ) Color 255, 255, 0 Text 20, 75, " pCone: " + XYZ( pCone, True ) Text 400, 75, XYZ( pCone, False ) Color 150, 150, 0 Text 20, 100, "cSphere: " + XYZ( cSphere, True ) Text 400, 100, XYZ( cSphere, False ) End Function ; ****************************************************************** ; These two functions just format the text display. ; Without them there are too many numbers crowding the screen. Function Round#( x#, m# ) ; returns x rounded to multiple of m If m < 0.0 Then m = -m s# = Sgn( x ) If x < 0.0 Then x = -x diff# = x Mod m If diff < .5 * m Return ( x - diff ) * s Else Return ( m + x - diff ) * s End If End Function Function XYZ$( entity, globalFlag ) ex# = Round( EntityX( entity, globalFlag ), .001 ) ey# = Round( EntityY( entity, globalFlag ), .001 ) ez# = Round( EntityZ( entity, globalFlag ), .001 ) Return RSet( ex, 8 ) + RSet( ey, 8 ) + RSet( ez, 8 ) End Function |