simd_float4x4 列

我想平移平面而不旋转图像。出于某种原因，我的图像正在旋转。

var translation = matrix_identity_float4x4
translation.colum = -0.2
let transform = simd_mul(currentFrame.camera.transform, translation)
planeNode.simdWorldTransform = matrix_multiply(currentFrame.camera.transform, translation)

另外，我注意到matrix_identity_float4x4包含 4 列，但文档不可用。

为什么是 4 列？有没有frame飞机的？

最简单的方法是使用以下代码进行定位：

let planeNode = SCNNode()
planeNode.geometry = SCNPlane(width: 20, height: 20)
// At first we need to rotate a plane about its x axis in radians:
planeNode.rotation = SCNVector4(1, 0, 0, -Double.pi/2)  
planeNode.geometry?.materials.first?.diffuse.contents = UIColor.red

planeNode.position.x = 10
planeNode.position.z = 10

// planeNode.position = SCNVector3(x: 10, y: 0, z: 10)

scene.rootNode.addChildNode(planeNode)

或者这样：

let cameraNode = SCNNode()
cameraNode.camera = SCNCamera()
cameraNode.position = SCNVector3(x: 0, y: 0, z: 15)
scene.rootNode.addChildNode(cameraNode)

let planeNode = SCNNode()
planeNode.geometry = SCNPlane(width: 20, height: 20)
planeNode.rotation = SCNVector4(1, 0, 0, -Double.pi/2)
planeNode.geometry?.materials.first?.diffuse.contents = UIColor.red

let distance: Float = 50
planeNode.simdPosition = cameraNode.simdWorldFront * distance  // -Z axis
planeNode.simdPosition = cameraNode.simdWorldRight * distance  // +X axis

scene.rootNode.addChildNode(planeNode)

如果您想了解有关 ARKit 和 SceneKit 框架中使用的矩阵的更多信息，请查看图1-8 https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/CoreAnimation_guide/CoreAnimationBasics/CoreAnimationBasics.html#//apple_ref/doc/uid/TP40004514-CH2-SW18 常见转换的矩阵配置.

希望这可以帮助。