要自定义 ARKit 中 SCNBox 的几何形状，可以使用以下代码示例：

// 创建一个 SCNBox，并设置自定义几何形状
let box = SCNBox(width: 0.1, height: 0.05, length: 0.15, chamferRadius: 0)
// 自定义 SCNGeometrySource 中的顶点
let vertices: [SCNVector3] = [
    SCNVector3(x: 0, y: 0, z: 0),
    SCNVector3(x: 0, y: 0.1, z: 0),
    SCNVector3(x: 0.1, y: 0, z: 0),
    SCNVector3(x: 0.1, y: 0.1, z: 0),
    SCNVector3(x: 0, y: 0, z: 0.15),
    SCNVector3(x: 0, y: 0.1, z: 0.15),
    SCNVector3(x: 0.1, y: 0, z: 0.15),
    SCNVector3(x: 0.1, y: 0.1, z: 0.15),
]
let vertexSource = SCNGeometrySource(vertices: vertices)
box.geometry?.setGeometrySources([vertexSource], for: .vertex)
// 使用自定义的顶点索引更新 SCNGeometryElement 中的三角形索引
let vertexIndices: [UInt16] = [0, 1, 3, 3, 2, 0, 2, 3, 7, 7, 6, 2, 6, 7, 5, 5, 4, 6, 4, 5, 1, 1, 0, 4, 4, 0, 2, 2, 6, 4, 1, 5, 7, 7, 3, 1]
let indexData = Data(bytes: vertexIndices, count: MemoryLayout.size * vertexIndices.count)
let element = SCNGe