Ios 多采样离屏渲染

我画了一个四边形并添加了纹理，画了一个小四边形并添加了纹理。当样本数为4时，当添加小四元时，我得到以下错误。当样本数为1时，工作正常

Execution of the command buffer was aborted due to an error during execution. Ignored (for causing prior/excessive GPU errors) (IOAF code 4)

如何使用样本计数4

guard let drawable = view.currentDrawable else { return }

let textureDescriptor = MTLTextureDescriptor()

textureDescriptor.textureType = MTLTextureType.type2DMultisample
textureDescriptor.width = drawable.texture.width
textureDescriptor.height = drawable.texture.height
textureDescriptor.pixelFormat = .bgra8Unorm
textureDescriptor.storageMode = .shared
 textureDescriptor.sampleCount = 4

textureDescriptor.usage = [.renderTarget, .shaderRead]
let sampleTexture = device.makeTexture(descriptor: textureDescriptor)


let renderPass = MTLRenderPassDescriptor()
renderPass.colorAttachments[0].texture = sampleTexture
renderPass.colorAttachments[0].resolveTexture = outTexture
renderPass.colorAttachments[0].loadAction = .clear
renderPass.colorAttachments[0].clearColor =
    MTLClearColor(red: 1.0, green: 1.0, blue: 1.0, alpha: 1.0)
 renderPass.colorAttachments[0].storeAction = .multisampleResolve

let commandBuffer = commandQueue.makeCommandBuffer()

let semaphore = inFlightSemaphore

commandBuffer?.addCompletedHandler { (_ commandBuffer)-> Swift.Void in
        semaphore.signal()
}

var commandEncoder = commandBuffer?.makeRenderCommandEncoder(descriptor: renderPass)

for scene in scenes {
    scene.render(commandEncoder: commandEncoder!)
}

commandEncoder?.endEncoding()


let descriptor = view.currentRenderPassDescriptor
commandEncoder = commandBuffer?.makeRenderCommandEncoder(descriptor: descriptor!)



for x in canvasScenes{
    x.updateCanvas(texture: sampleTexture!)
    x.render(commandEncoder: commandEncoder!)
}

commandEncoder?.endEncoding()


commandBuffer?.present(drawable)
commandBuffer?.commit()
commandBuffer?.waitUntilCompleted()

---

这是我的设置屏幕外渲染与多采样。我也使用深度纹理。下面是关于多重采样的小说明

---

如果使用MSAA绘制（即，渲染管道状态具有

sampleCount

>0），则必须满足以下条件：（1）渲染过程描述符颜色附件必须设置类型为

type2D

的

resolveTexture

；（2） 设置为颜色附件的

纹理的纹理必须是
类型。type2DMultisample
；（3）其
sampleCount
必须与渲染管道状态匹配。就我所见，在您发布的代码中没有一个是正确的，尽管这应该被验证层捕获。（是否在启用验证的情况下运行？）金属验证I已禁用。禁用时，我可以绘制一个四元错误出现在第二个四元图形中。Yh如果验证启用错误comes@warrenm我让textureDescriptors纹理类型转换为2D Multisample类型，样本数为4，并将纹理解析为outTexture类型MTLTexture的变量，和renderpass描述符将操作存储到multisample resolve当我这样做时，我收到以下错误消息失败断言'MTLRenderPassDescriptor MTLStoreActionMultisampleResolve存储操作需要解析纹理'textureDescriptor.textureType=MTLTextureType.type2DMultisample。textureDescriptor.sampleCount=4 renderPass.colorAttachments[0]。resolveTexture=outTexture。renderPass.colorAttachments[0]。storeAction=.multisampleResolve。这些是我在上述代码中所做的更改，并收到上述错误消息
    let offscreenTextureDescriptor = MTLTextureDescriptor()
    offscreenTextureDescriptor.width = size.width
    offscreenTextureDescriptor.height = size.height
    offscreenTextureDescriptor.depth = size.depth
    offscreenTextureDescriptor.pixelFormat = RenderPixelFormat.offscreen.rawValue.mtlPixelFormat()
    offscreenTextureDescriptor.textureType = .type2DMultisample
    offscreenTextureDescriptor.storageMode = .shared
    offscreenTextureDescriptor.usage = [.renderTarget, .shaderRead, .shaderWrite, .pixelFormatView]
    offscreenTextureDescriptor.sampleCount = 4

    self.offScreenTexture = device.makeTexture(descriptor: offscreenTextureDescriptor)

    offscreenTextureDescriptor.textureType = .type2D
    offscreenTextureDescriptor.sampleCount = 1
    offscreenTextureDescriptor.usage = [.shaderWrite]

    self.resolveOffScreenTexture = device.makeTexture(descriptor: offscreenTextureDescriptor)

    let depthTextureDescriptor = MTLTextureDescriptor.texture2DDescriptor(pixelFormat: .depth32Float, width: self.offScreenTexture.width, height: self.offScreenTexture.height, mipmapped: false)
    depthTextureDescriptor.usage = [.renderTarget, .shaderRead, .shaderWrite, .pixelFormatView]
    depthTextureDescriptor.textureType = .type2DMultisample
    depthTextureDescriptor.storageMode = .private
    depthTextureDescriptor.resourceOptions = [.storageModePrivate]
    depthTextureDescriptor.sampleCount = 4

    let depthAttachementTexureDescriptor = MTLRenderPassDepthAttachmentDescriptor()
    depthAttachementTexureDescriptor.clearDepth = 1.0
    depthAttachementTexureDescriptor.loadAction = .clear
    depthAttachementTexureDescriptor.storeAction = .store
    depthAttachementTexureDescriptor.texture = device.makeTexture(descriptor: depthTextureDescriptor)

    let renderPassDescriptor = MTLRenderPassDescriptor()
    renderPassDescriptor.colorAttachments[0].texture = self.offScreenTexture
    renderPassDescriptor.colorAttachments[0].resolveTexture = self.resolveOffScreenTexture
    renderPassDescriptor.colorAttachments[0].clearColor = MTLClearColorMake(0, 0, 0, 1)
    renderPassDescriptor.colorAttachments[0].loadAction = .clear
    renderPassDescriptor.colorAttachments[0].storeAction = .multisampleResolve
    renderPassDescriptor.depthAttachment = depthAttachementTexureDescriptor
    self.renderPassDescriptor = renderPassDescriptor