Swift ARKit SCNGeometry 呈現半透明在 SCNNode

let geometry:SCNGeometry

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let material = SCNMaterial()

material.diffuse.contents = UIColor(red: 255.0 / 255.0, green: 0 / 255.0, blue: 0 / 255.0, alpha: 0.8) // 设置半透明颜色

                            

let boxNode = SCNNode()

boxNode.geometry = geometry

boxNode.geometry?.materials = [material]

boxNode.position = SCNVector3(0, -2, -2)