3D object flips sometimes the wrong way around

fsw · Post by **fsw** » Wed Jun 11, 2003 1:24 am

Hi ALL
here is some 3D code that I play with.

It shows 2 electronic components (not finished though...)
With F1 you can restart the object position.
If you start from there and press the arrow-down or arrow-up keys you will see that the object sometimes is flipped over.
As orientation you can look at the red circle and a leg on one object.
You can use the arrow-keys and delete/insert to move your position.
With PageUp/PageDown you can move back and forth.
With Home/End you can change a constant. If this constant is 2.828 you have isometric view. (but it's buggy...)

Hope somebody is able to help me out here...
I need consistent movement and not objects flipping around.
Hope I made myself clear and somebody can see the difference...

Thanks in advance
Franco

Code: Select all

; 3D_Example coded by Franco
; based on an initial isometric 3D-code from DeeÃ©m2031 (german forum)

#Pi.f=3.1415626

;Don't know what this is... anyway:
;good visual results for CAD with 36000
Constant.f=360 * 360 ; to be on the save side...

;For gaming: 2.828 -> isometric
;Constant.f = 2 * Sqr(2)


CameraPosition.f = 18

Procedure d_init3d(ScreenWidth.l,ScreenHeight.l)
  
  ; write sin und cos in Array
  Dim _sin.f(360)
  Dim _cos.f(360)

  For i = 0 To 360
    _sin(i) = Sin(i/(180/#Pi))
    _cos(i) = Cos(i/(180/#Pi))
  Next i
  
  ; Screen stuff...
  Global ScreenWidth2.l
  Global ScreenHeight2.l

  ScreenWidth2.l = Round((ScreenWidth/2),0)
  ScreenHeight2.l = Round((ScreenHeight/2),0)
  
  Global wx.l
  Global wy.l
  Global wz.l

EndProcedure

Procedure.f CalcXRotation(x.f,y.f,z.f)
  Result.f = _cos(wy) * _cos(wz) * x - _cos(wy) * _sin(wz) * y + _sin(wy) * z
  ProcedureReturn Result
EndProcedure

Procedure.f CalcYRotation(x.f,y.f,z.f)
  Result.f =  (_cos(wx) * _sin(wz) + _sin(wx) * _sin(wy) * _cos(wz)) * x + (_cos(wx) * _cos(wz) - _sin(wx) * _sin(wy) * _sin(wz)) * y - _sin(wx) * _cos(wy) * z
  ProcedureReturn Result
EndProcedure

Procedure.f CalcZRotation(x.f,y.f,z.f)
  Result.f =  (_sin(wx) * _sin(wz) - _cos(wx) * _sin(wy) * _cos(wz)) *y + (_sin(wx) * _cos(wz) + _cos(wx) * _sin(wy) * _sin(wz)) * y + _cos(wx) * _cos(wy) * z
  ProcedureReturn Result
EndProcedure

Procedure CheckXRotation(x.l)
  If x >= 360
    Repeat
      x - 360
    Until x >= 0 And x < 360
  EndIf
  If x < 0
    Repeat
      x + 360
    Until x >= 0 And x < 360
  EndIf
  ProcedureReturn x
EndProcedure

Procedure CheckYRotation(y.l)
  If y >= 360
    Repeat
      y - 360
    Until y >= 0 And y < 360
  EndIf
  If y < 0
    Repeat
      y + 360
    Until y >= 0 And y < 360
  EndIf
  ProcedureReturn y
EndProcedure
  
Procedure CheckZRotation(z.l)
  If z >= 360
    Repeat
      z - 360
    Until z >= 0 And z < 360
  EndIf
  If z < 0
    Repeat
      z + 360
    Until z >= 0 And z < 360
  EndIf
  ProcedureReturn z
EndProcedure

Procedure d_circle3d(x1.f,y1.f,z1.f,diameter.f)
  Shared Constant, CameraPosition
  ; calculate rotation
  xx.f = CalcXRotation(x1*CameraPosition,y1*CameraPosition,z1*CameraPosition)
  yy.f = CalcYRotation(x1*CameraPosition,y1*CameraPosition,z1*CameraPosition)
  zz.f = CalcZRotation(x1*CameraPosition,y1*CameraPosition,z1*CameraPosition)

  ; 1. convert to 2D coordinates 
  ; 2. draw it...
  Circle(Round(xx-zz/Constant,0)+ScreenWidth2,Round(yy-zz/Constant,0)+ScreenHeight2, diameter*CameraPosition) 
EndProcedure

Procedure d_line3d(x1.f,y1.f,z1.f,x2.f,y2.f,z2.f)
  Shared Constant,CameraPosition

  ; calculate rotation
  xx.f = CalcXRotation(x1*CameraPosition,y1*CameraPosition,z1*CameraPosition)
  yy.f = CalcYRotation(x1*CameraPosition,y1*CameraPosition,z1*CameraPosition)
  zz.f = CalcZRotation(x1*CameraPosition,y1*CameraPosition,z1*CameraPosition)

  xx2.f = CalcXRotation(x2*CameraPosition,y2*CameraPosition,z2*CameraPosition)
  yy2.f = CalcYRotation(x2*CameraPosition,y2*CameraPosition,z2*CameraPosition)
  zz2.f = CalcZRotation(x2*CameraPosition,y2*CameraPosition,z2*CameraPosition)

  ; 1. convert to 2D coordinates 
  ; 2. draw it...
    LineXY(Round(xx-zz/Constant,0)+ScreenWidth2,Round(yy-zz/Constant,0)+ScreenHeight2,Round(xx2-zz2/Constant,0)+ScreenWidth2,Round(yy2-zz2/Constant,0)+ScreenHeight2)
EndProcedure


;- Init stuff

InitSprite()
InitMouse()
InitKeyboard()

d_init3d(1024,768)

OpenWindow(1,100,200,750,480,#PB_Window_SystemMenu,"Test")
OpenWindowedScreen( WindowID(),10,10,800,600,1,10,10)

;- main program

x.f = 0
y.f = 0
z.f = 0

Start.l = 1

Repeat
 ExamineMouse()
 ExamineKeyboard()
  
 ; check rotation -> if x, y and z <0 or >360 error
  wx = CheckXRotation(x)
  wy = CheckYRotation(y)
  wz = CheckZRotation(z)
  

  
  ClearScreen(0,0,0)
  StartDrawing(ScreenOutput())
  
  ; DrawingMode:
  ;  0: Default mode, text is displayed with background, graphics shape are filled 
  ;  1: Set the text background transparent 
  ;  2: Enable the XOr mode (all graphics are XOR'ed with current background) 
  ;  4: Enable the outlined shape. Circle, Box etc... will be only outlined, no more filled. 
  DrawingMode(0) 


  ; set the circle on top of the component 
  FrontColor(255,0,0)
  d_circle3d(0,0,4,0.2)


  FrontColor(255,255,255)


; IC SOL18-P-300-1.27 Toshiba ULN2803 
; dimensions in millimeter
; body top
  d_line3d( -15.775, 3.75, 1.15,-25.775, 3.75, 1.15)
  d_line3d( -15.775,-3.75, 1.15,-25.775,-3.75, 1.15)
  d_line3d( -25.775, 3.75, 1.15,-25.775,-3.75, 1.15)
  d_line3d( -15.775, 3.75, 1.15,-15.775,-3.75, 1.15)
;body bottom
  d_line3d( -15.775, 3.75,-1.15,-25.775, 3.75,-1.15)
  d_line3d( -15.775,-3.75,-1.15,-25.775,-3.75,-1.15)
  d_line3d( -25.775, 3.75,-1.15,-25.775,-3.75,-1.15)
  d_line3d( -15.775, 3.75,-1.15,-15.775,-3.75,-1.15)
;body z corners
  d_line3d( -25.775, 3.75, 1.15,-25.775, 3.75,-1.15)
  d_line3d( -15.775, 3.75, 1.15,-15.775, 3.75,-1.15)
  d_line3d( -25.775,-3.75, 1.15,-25.775,-3.75,-1.15)
  d_line3d( -15.775,-3.75, 1.15,-15.775,-3.75,-1.15)


; IC SOL18-P-300-1.27 Toshiba ULN2803 
; dimensions in millimeter
; body top
  d_line3d( -5.775, 3.75, 1.15, 5.775, 3.75, 1.15)
  d_line3d( -5.775,-3.75, 1.15, 5.775,-3.75, 1.15)
  d_line3d(  5.775, 3.75, 1.15, 5.775,-3.75, 1.15)
  d_line3d( -5.775, 3.75, 1.15,-5.775,-3.75, 1.15)
;body bottom
  d_line3d( -5.775, 3.75,-1.15, 5.775, 3.75,-1.15)
  d_line3d( -5.775,-3.75,-1.15, 5.775,-3.75,-1.15)
  d_line3d(  5.775, 3.75,-1.15, 5.775,-3.75,-1.15)
  d_line3d( -5.775, 3.75,-1.15,-5.775,-3.75,-1.15)
;body z corners
  d_line3d(  5.775, 3.75, 1.15, 5.775, 3.75,-1.15)
  d_line3d( -5.775, 3.75, 1.15,-5.775, 3.75,-1.15)
  d_line3d(  5.775,-3.75, 1.15, 5.775,-3.75,-1.15)
  d_line3d( -5.775,-3.75, 1.15,-5.775,-3.75,-1.15)
 

;lead # 5
  d_line3d(  0.24, 3.75, 0.14,-0.24, 3.75, 0.14)
  d_line3d(  0.24, 3.75,-0.14,-0.24, 3.75,-0.14)
  d_line3d(  0.24, 3.75, 0.14, 0.24, 3.75,-0.14)
  d_line3d( -0.24, 3.75, 0.14,-0.24, 3.75,-0.14)
  
  d_line3d(  0.24, 3.75, 0.14, 0.24, 4.49, 0.14)
  d_line3d( -0.24, 3.75, 0.14,-0.24, 4.49, 0.14)
  d_line3d(  0.24, 3.75,-0.14, 0.24, 4.31,-0.14)
  d_line3d( -0.24, 3.75,-0.14,-0.24, 4.31,-0.14)

  d_line3d(  0.24, 4.49, 0.14, 0.24, 4.49,-1.22)
  d_line3d( -0.24, 4.49, 0.14,-0.24, 4.49,-1.22)
  d_line3d(  0.24, 4.31,-0.14, 0.24, 4.31,-1.50)
  d_line3d( -0.24, 4.31,-0.14,-0.24, 4.31,-1.50)
  d_line3d(  0.24, 4.49, 0.14,-0.24, 4.49, 0.14)
  d_line3d(  0.24, 3.75,-0.14,-0.24, 3.75,-0.14)

  d_line3d(  0.24, 4.49,-1.22, 0.24, 5.15,-1.22)
  d_line3d( -0.24, 4.49,-1.22,-0.24, 5.15,-1.22)
  d_line3d(  0.24, 4.31,-1.50, 0.24, 5.15,-1.50)
  d_line3d( -0.24, 4.31,-1.50,-0.24, 5.15,-1.50)

  d_line3d(  0.24, 5.15,-1.22,-0.24, 5.15,-1.22)
  d_line3d(  0.24, 5.15,-1.50,-0.24, 5.15,-1.50)
  d_line3d(  0.24, 5.15,-1.22, 0.24, 5.15,-1.50)
  d_line3d( -0.24, 5.15,-1.22,-0.24, 5.15,-1.50)

  StopDrawing()
  FlipBuffers()
  
  ExamineKeyboard()

  If KeyboardPushed(#PB_Key_Home) 
    Constant = Constant * 1.02
    SetWindowText_(WindowID(),StrF(Constant))
  EndIf
  If KeyboardPushed(#PB_Key_End) 
    Constant = Constant * 0.98
    SetWindowText_(WindowID(),StrF(Constant))
  EndIf

  If KeyboardPushed(#PB_Key_PageUp) 
    CameraPosition = CameraPosition * 1.02
  EndIf
  If KeyboardPushed(#PB_Key_PageDown) 
    CameraPosition = CameraPosition * 0.98
  EndIf

  If KeyboardPushed(#PB_Key_Up) 
    x = x - 1 ;normally it should be y
  EndIf
  If KeyboardPushed(#PB_Key_Down) 
    x = x + 1 ;normally it should be y
  EndIf

  If KeyboardPushed(#PB_Key_Right) 
    y = y  - 1 ;normally it should be x
  EndIf
  If KeyboardPushed(#PB_Key_Left) 
    y = y + 1 ;normally it should be x
  EndIf
  
  If KeyboardPushed(#PB_Key_Delete) 
    z = z - 1
  EndIf
  If KeyboardPushed(#PB_Key_Insert) 
    z = z + 1
  EndIf

  If KeyboardPushed(#PB_Key_F1) 
    x = 0
    y = 0
    z = 0
  EndIf

  SetWindowText_(WindowID()," X: " + Str(wx) + "   Y: " + Str(wy) + "   Z: " + Str(wz) + "   SinX: " + StrF(_sin(wx),2) + "   SinY: " + StrF(_sin(wy),2) + "   SinZ: " + StrF(_sin(wz),2) + "   CosX: " + StrF(_cos(wx),2) + "   CosY: " + StrF(_cos(wy),2) + "   CosZ: " + StrF(_cos(wz),2) + "   Constant: " + StrF(Constant))
Until MouseButton(1) Or KeyboardPushed(#PB_Key_Escape)
End

HarryO · Post by **HarryO** » Wed Jun 11, 2003 5:45 am

fsw,

Tried your code... Not inconsistant! Here are my observations from
testing.

After pressing F1:

When you press the down arrow key, Red dot and leg consistantly
point in one direction, towards the top side.

When you press the up arrow key, Red dot and leg consistantly
point in one direction, towards the bottom side.

It's like it will consistantly react the same way, it just depends on
the initial direction you chose.

Hope this helps. BTW.... W98SE system & looks cool.

HarryO

fsw · Post by **fsw** » Wed Jun 11, 2003 5:02 pm

HarryO,
that's exactly what I observe, and I have no clue how to get it right...

Thanks for testing, though.

Has somebody an idea

Andy Amaya · Post by **Andy Amaya** » Wed Jul 23, 2003 4:22 am

Hi new to Pure Basic, but not to programming.

I know little to nothing about the 3D portion of the code, but in the loop to assign values to _cos() and _sin(), use the following format to obtain radian equivalent of degree results.

_cos(i) = Cos(i * 3.1415926/180)
_sin(i) = Sin(i * 3.1415926/180)

Not doing so would definitely cause consistently undesired results.

You can verify that above formula is correct by plugging in angles for Cos() and Sin() for which the answers are obvious.

Example:
If i = 0 degrees then Cos (0) = 1, Sin (0) = 0
If i = 90 degrees then Cos (90) = 0, Sin (90) = 1
If i = 180 degrees then Cos(180) = -1, Sin(180) = 0
If i = 270 degrees then Cos(270) = 0, Sin(270) = -1

The other thing that may help is PI = Atan(1)*4 defines to limit of internal storage, value of PI.

Hope this helps,

Andy