swift – 在SceneKit中重复平面上的纹理

我有一个32×32 .png图像,我想通过SCNPlane重复.我得到的代码(见下文)导致图像被拉伸以适应平面的大小,而不是重复.

码：

let planeGeo = SCNPlane(width: 15,height: 15)

let imageMaterial = SCNMaterial()
imageMaterial.diffuse.contents = UIImage(named: "art.scnassets/grid.png")

planeGeo.firstMaterial = imageMaterial

let plane = SCNNode(geometry: planeGeo)

plane.geometry?.firstMaterial?.diffuse.wrapS = SCNWrapMode.repeat
plane.geometry?.firstMaterial?.diffuse.wrapT = SCNWrapMode.repeat

我修好了它.看起来图像被放大了.如果我做imageMaterial.diffuse.contentsTransform = SCNMatrix4MakeScale(32,32,0),图像会重复.