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15. April 2018


A couple days back AppGameKit v2018.4.12 was released with the major new feature being AR (Augmented Reality) support.  I decided to give the new AR functionality a shot and it was really impressive how easy it was.  In order to get started with AR and AppGameKit you are going to need an AR compatible device.  On iOS, this means an ARKit compatible device, which basically means an iPhone 6S or newer device, while on Android device you need an ARCore compatible device from this list of phones.


I modified the AR example slightly, to remove a bit of functionality and to instead load a simple Tie Fighter model I downloaded off the web and converted to .X format.  AppGameKit can be coded using either C++ or their higher level Basic like script, which is what was used in this example.  Here is the slightly modified source code used:

// set window properties
SetWindowTitle( "AR Tie Fighter" )
SetWindowSize( 1024, 768, 0 )

// set display properties
SetVirtualResolution( 1024, 768 )
SetOrientationAllowed( 1, 1, 1, 1 )
SetScissor(0,0,0,0)
SetClearColor( 101,120,154 )
SetGenerateMipmaps( 1 )
UseNewDefaultFonts(1)
SetPrintSize(20)

// camera range from 0.1 meters to 40 meters
SetCameraRange( 1, 0.1, 40 )
SetAmbientColor( 128,128,128 )
SetSunColor( 255,255,255 )

// load tie fighter
LoadObject( 1, "tie.x")
SetObjectPosition( 1, 0,0.1,0 )
LoadImage(1, "diffuse.jpg")
SetObjectImage (1,1,0) 
SetObjectRotation(1,270,0,0)

function ShowModel( show as integer )
  SetObjectVisible( 1, show )
endfunction

ShowModel( 0 )

function ScaleModel( amount as float )
  SetObjectScalePermanent( 1, amount, amount, amount )
endfunction

ScaleModel( 0.025 )

// create some planes to show detected surfaces, initially hidden
for i = 101 to 150
  CreateObjectPlane( i, 1,1 )
  SetObjectRotation( i, 90,0,0 )
  FixObjectPivot( i )
  SetObjectVisible( i, 0 )
  SetObjectColor( i, 255,255,255,128 ) // 50% transparent
  SetObjectTransparency( i, 1 )
next i

// add some buttons to control various features
AddVirtualButton( 1, 100,565,100 )
AddVirtualButton( 2, 100,665,100 )
SetVirtualButtonText( 1, "Scale +" )
SetVirtualButtonText( 2, "Scale -" )

AddVirtualButton( 3, 924,665,100 )
SetVirtualButtonText( 3, "Hide" )

function ShowHUD( show as integer )
  SetVirtualButtonVisible( 1, show )
  SetVirtualButtonVisible( 2, show )
  SetVirtualButtonVisible( 3, show )
  SetVirtualButtonActive( 1, show )
  SetVirtualButtonActive( 2, show )
  SetVirtualButtonActive( 3, show )
endfunction

// initialize AR, if possible
ARSetup()
while( ARGetStatus() = 1 )
  // wait while user is being prompted to install ARCore
  Sync()
endwhile

AnchorID as integer = 0
ShowPlanes as integer = 1
ambientScale# = 1.0

do
  // get light estimation
  ambient = ARGetLightEstimate() * 255 * ambientScale#
  SetAmbientColor( ambient,ambient,ambient )
  
  // check screen tap for plane hits, but only if buttons are visible
  if ( GetPointerReleased() and ShowPlanes = 1 )
    // check the point that the user tapped on the screen
    numHits = ARHitTest( GetPointerX(), GetPointerY() )
    if ( numHits > 0 )
      ShowModel( 1 )
      // delete any previous anchor, could keep it around instead
      if ( AnchorID > 0 ) then ARDeleteAnchor( AnchorID )
      // hit test results are ordered from closest to furthest
      // place the object at result 1, the closest
      AnchorID = ARCreateAnchorFromHitTest( 1 )
      ARFixObjectToAnchor( 1, AnchorID )
    else
      // if the user didn't tap on any planes then hide the object
      ShowModel( 0 )
    endif
    // clean up some internal resources
    ARHitTestFinish()
  endif
  
  // place the buttons at the edge of the screen
  // needs to be done regularly in case orientation changes
  SetVirtualButtonPosition( 1, GetScreenBoundsLeft()+105, GetScreenBoundsBottom()-210 )
  SetVirtualButtonPosition( 2, GetScreenBoundsLeft()+105, GetScreenBoundsBottom()-105 )
  SetVirtualButtonPosition( 3, GetScreenBoundsRight()-105, GetScreenBoundsBottom()-105 )
  
  // detect button presses if they are visible
  if ( ShowPlanes = 1 )
    if ( GetVirtualButtonPressed(1) )
      ScaleModel( 1.05 )
    endif
    if ( GetVirtualButtonPressed(2) )
      ScaleModel( 0.95 )
    endif
    if ( GetVirtualButtonPressed(3) )
      ShowPlanes = 1 - ShowPlanes
      ShowHUD( 0 )
    endif
  else
    // screen tap whilst button are hidden shows them again
    if ( GetPointerReleased() )
      ShowPlanes = 1 - ShowPlanes
      ShowHUD( 1 )
    endif
  endif
  
  // hide old planes
    for i = 101 to 150
    SetObjectVisible( i, 0 )
  next i
  
  // show detected planes
  if ( ShowPlanes )
    numPlanes = ARGetPlanes(0)
    // this demo stops at 50 planes, but there is no internal limit
    if numPlanes > 50 then numPlanes = 50
    for i = 1 to numPlanes
      SetObjectPosition( i+100, ARGetPlaneX(i), ARGetPlaneY(i), ARGetPlaneZ(i) )
      SetObjectRotation( i+100, ARGetPlaneAngleX(i), ARGetPlaneAngleY(i), ARGetPlaneAngleZ(i) )
      SetObjectScale( i+100, ARGetPlaneSizeX(i), 1, ARGetPlaneSizeZ(i) )
      SetObjectVisible( i+100, 1 )
    next i
    ARGetPlanesFinish()
  endif
    
    if ( ShowPlanes )
    Print( "FPS: " + str(ScreenFPS()) )
    select( ARGetStatus() )
      case 2 :  Print( "AR Active" ) : endcase
      case -1 :  Print( "AR Not Available" ) : endcase
      case -2 :  Print( "AR Install Rejected" ) : endcase
    endselect
    Print( "Number of Planes Detected: " + str(numPlanes) )
    Print( "Light Estimation: " + str(ARGetLightEstimate()) )
    Print( "Light Boost: " + str(ambientScale#,1) )
  endif
    
  // draw the camera feed, and then the rest of the scene
  ARDrawBackground()
    Sync()
    RotateObjectLocalZ(1,1)
loop


You can see the results of this code and get a bit more detail by watching the video below:


If you are interested in learning more about AppGameKit, be sure to check out our Closer Look available here.

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