360° panorama view

equirectangular projections

OpenGL, device-oriented, touch-interactive

acceptable image sizes: (4096×2048), 2048×1024, 1024×512, 512×256, 256×128 ...

• (4096 supported on iPhone 4s and iPad2 onward)

#methods

image

-(void) setImage:(UIImage*)image;
-(void) setImageWithName:(NSString*)fileName;  // path or bundle. will check at both

orientation

 // auto-update (usually only one of these at a time is recommended)
-(void) setOrientToDevice:(BOOL)   // activate motion sensors
-(void) setTouchToPan:(BOOL)       // activate UIPanGesture

 // aligns z-axis (into screen)
-(void) orientToVector:(GLKVector3)
-(void) orientToAzimuth:(float) Altitude:(float)

field of view

-(void) setFieldOfView:(float)     // in degrees
-(void) setPinchToZoom:(BOOL)      // activate UIPinchGesture

touches

-(void) setShowTouches:(BOOL)      // overlay latitude longitude intersects
-(BOOL) touchInRect:(CGRect)       // hotspot detection in world coordinates

2D - 3D conversion

-(CGPoint) screenLocationFromVector:(GLKVector3) // 2D screen point from a 3D point
-(GLKVector3) vectorFromScreenLocation:(CGPoint) // 3D point from 2D screen point
-(CGPoint) imagePixelAtScreenLocation:(CGPoint)  // 3D point from 2D screen point
  // except this 3D point is expressed as 2D pixel unit in the panorama image

VR Split screen

-(void) setVRMode:(BOOL)

This activates a split screen that works inside of VR headsets like Google Cardboard. TBD if more VR best practices are needed, such as a barrel shader.

• Illusion of varying depth is not available. The two screens are rendered using the same image with no difference between camera IPD.

usage

make your ViewController a subclass of GLKViewController

panoramaView = [[PanoramaView alloc] init];
 // load image and any other customization
[self setView:panoramaView];

also in your GLKViewController:

-(void) glkView:(GLKView *)view drawInRect:(CGRect)rect{
    [panoramaView draw];
}

make sure

• no device landscape/portrait auto-rotation

• works properly under any of the 4 device orientations

swift

class MainView: GLKViewController {
    
    var panoramaView = PanoramaView()
    
    override func viewDidLoad() {
        panoramaView.setImageWithName("imagename.jpg")
        panoramaView.touchToPan = true          // Use touch input to pan
        panoramaView.orientToDevice = false     // Use motion sensors to pan
        panoramaView.pinchToZoom = true         // Use pinch gesture to zoom
        panoramaView.showTouches = true         // Show touches
        self.view = panoramaView
    }
    
    override func glkView(view: GLKView, drawInRect rect: CGRect) {
        panoramaView.draw()
    }
}

orientation

• azimuth and altitude
• look direction, the Z vector pointing through the center of the screen

The program begins by facing the center column of the image, or azimuth 0°

about equirectangular

equirectangular images mapped to the inside of a celestial sphere come out looking like the original scene, and the math is relatively simple http://en.wikipedia.org/wiki/Equirectangular_projection

license

MIT