SceneKit, Zoom camera to fit node

Question

Hi i have a very simple scene that contains 3 nodes:

• Light
• Camera
• Stl

When placing the STL it is very small so the user has to zoom the camera an aweful lot. What i would like to do is to zoom the camera to the fit STL node programatically but im not sure how.

This is wat i have so far:

stlNode = .... // Custom node
lightNode = scene?.rootNode.childNode(withName: "omni", recursively: true)
        cameraNode = scene?.rootNode.childNode(withName: "camera", recursively: true)

        cameraNode.constraints  = [SCNLookAtConstraint(target: stlNode)]
// Zoom to fit the stlNode here.
        scene?.rootNode.addChildNode(stlNode)

Answer 1

You might try creating a cameraClass, then add zoomIn(),zoomOut() functions so that you can make adjustments. You could also scale your node up a bit, see if that helps.

var cameraEye = SCNNode()
var cameraFocus = SCNNode()

...
init()
    {
        cameraEye.name = "Camera Eye"
        cameraFocus.name = "Camera Focus"

        cameraFocus.isHidden = true
        cameraFocus.position  =  SCNVector3(x: 0, y: 0, z: 0)

        cameraEye.camera = SCNCamera()
        cameraEye.constraints = []
        cameraEye.position = SCNVector3(x: 0, y: 15, z: 0.1)

        let vConstraint = SCNLookAtConstraint(target: cameraFocus)
        vConstraint.isGimbalLockEnabled = true
        cameraEye.constraints = [vConstraint]
    }
// Add your camera nodes
gameNodes.addChildNode(camera.cameraEye)
gameNodes.addChildNode(camera.cameraFocus)

ZoomIn()/zoomOut() would just be a function of adjusting your distance.