Open Radar

 
Area:
SceneKit

Summary:
I want to do terrain deform and I created a SCNPlane, change its segments on width & height to 149, the vertex count should be  150*150, but it returns 4. If I put a "Thread.Sleep" between the call, I get 22500.

Steps to Reproduce:
let GOLF_SITE_SQUARE_MESH_SEGMENTS_COUNT : Int = 149
let GOLF_SITE_SQUARE_MESH_SIZE : Float = 16000.0
var planeMeshGeometry : SCNPlane = SCNPlane(width: CGFloat(GOLF_SITE_SQUARE_MESH_SIZE), height: CGFloat(GOLF_SITE_SQUARE_MESH_SIZE))
planeMeshGeometry.widthSegmentCount = GOLF_SITE_SQUARE_MESH_SEGMENTS_COUNT
        planeMeshGeometry.heightSegmentCount = GOLF_SITE_SQUARE_MESH_SEGMENTS_COUNT
        planeMeshGeometry.cornerRadius = 0.0
//Thread.sleep(forTimeInterval: 0.1)

 var vertexSources : [SCNGeometrySource] = planeMeshGeometry.sources(for: .vertex)
        let vertexSource : SCNGeometrySource = vertexSources[0]
        
        var texCoordSources : [SCNGeometrySource] = planeMeshGeometry.sources(for: .texcoord)
        let texCorrdSource : SCNGeometrySource = texCoordSources[0]
        
        let stride : Int = vertexSource.dataStride
        let offest : Int = vertexSource.dataOffset
        let componentsPerVector : Int = vertexSource.componentsPerVector
        let bytesPerVector : Int = componentsPerVector * vertexSource.bytesPerComponent
        let vectorCount : Int = vertexSource.vectorCount
        print(vectorCount)
        var vertices : [SCNVector3] = [SCNVector3](repeatElement(SCNVector3(0,0,0), count: vectorCount))
        for i in 0..<vectorCount
        {
            var vectorData : [Float] = [Float](repeatElement(0.0, count: 3))
            let byteRange : NSRange = NSMakeRange(i * stride + offest, bytesPerVector)
            let vertexData = vertexSource.data as NSData
            vertexData.getBytes(&vectorData, range: byteRange)
            
            let x : Float = vectorData[0]
            let y : Float = vectorData[1]
            let xNormalized : Float = x / GOLF_SITE_SQUARE_MESH_SIZE + 0.5
            let yNormalized : Float = 1 - (y / GOLF_SITE_SQUARE_MESH_SIZE + 0.5)
            
            let vectorToSample : vector_int2 = vector2(Int32(Int(xNormalized * Float(NOISE_SAMPLE_COUNT))), Int32(yNormalized * Float(NOISE_SAMPLE_COUNT)))
            let noiseValue : Float = (JZNoiseMapManager.shared.noiseMap.value(at: vectorToSample)) / 2.0 + 0.5
            
            let newVector : SCNVector3 = SCNVector3 (vectorData[0],vectorData[1],noiseValue*GOLF_SITE_SQUARE_MESH_SIZE / 2.0*GOLF_SITE_HEIGHT_MULTIPIER)
            vertices[i] = newVector
        }

Expected Results:
print(vectorCount) should output 22500 on matter if the Thread.Sleep exists.

Actual Results:
print(vectorCount) = 4 when no sleep.
print(vectorCount) = 22500 when sleep.

Version/Build:
Xcode 9.2 iOS 11.2.5

Configuration: