How to place SCNText inside SCNPlane?

Question

I am trying to create an AR app that have a number of SCNText and SCNPlane. And I am trying to place each SCNText inside the SCNPlane, but as this figure shows, the text becomes always outside the plane.

My Question is how can I place each SCNText inside the SCNPlane?

This is my code section:

func displayMark() {

    var str = ["Orange ","Apple ","Banana ","limon", "onion"]

    var x : Float = 1
    var i = 0
    while i<5 {

    let text = SCNText(string: str[i], extrusionDepth: 0)
    let material = SCNMaterial()
    material.diffuse.contents = UIColor.black
    text.materials = [material]

    let node = SCNNode()
    node.position = SCNVector3(0, x/15 , 0)
    node.scale = SCNVector3(0.0009, 0.0009, 0.0009)


    let planeNode2 = SCNNode(geometry: text)
     node.addChildNode(planeNode2)

    let minVec = node.boundingBox.min
    let maxVec = node.boundingBox.max
    let bound = SCNVector3Make(maxVec.x - minVec.x,
                               maxVec.y - minVec.y,
                               maxVec.z - minVec.z);



    let plane = SCNPlane(width: CGFloat(bound.x),
                         height: CGFloat(bound.y))
    plane.cornerRadius = 5
    plane.firstMaterial?.diffuse.contents = UIColor.gray.withAlphaComponent(0.8)


    let planeNode = SCNNode(geometry: plane)
    node.addChildNode(planeNode)
    planeNode.name = "text"
        i = i + 1
        x = 1 + x

        self.sceneView.scene.rootNode.addChildNode(node)
        self.sceneView.autoenablesDefaultLighting = true
    }
}

Andy Jazz · Answer 1 · 2022-11-04T14:51:55.920

The SCNText's peculiarity is that its pivot point (a.k.a. origin point) is located at a bottom of its left corner's container. Like that:

So you need to apply a regular formula to calculate the center location of a pivot point:

/*   ( Max dist - Min dist ) / 2                   for X and Y    */

Here's how a real code for repositioning pivot along X looks like:

sceneView.debugOptions = .showBoundingBoxes

let boundingBox = (abs(textNode.boundingBox.max.x) -
                   abs(textNode.boundingBox.min.x)) / 2
            
textNode.simdPivot.columns.3.x = boundingBox

Also it's a good idea to slightly offset the pivot along +Z direction if there's a deep extrusion.

How to place SCNText inside SCNPlane?

1 Answers1