问题描述

我将使用的一些网格并不总是有DiffuseMap或specularMap。当我试图加载没有漫反射和镜面反射贴图的对象时，程序崩溃，因为DiffuseMap.ImageView/specularMap.ImageView中没有任何内容，因为它没有指向任何内容。如果我尝试将Imageview/Sample设置为VK_NULL_HANDLE，程序会显示以下内容并在vkUpdateDescriptorSets：

Validation Layer: Invalid VkImageView Object 0x0. The Vulkan spec states: If descriptorType is VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE, VK_DESCRIPTOR_TYPE_STORAGE_IMAGE, or VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT, the imageView and imageLayout members of each element of pImageInfo must be a valid VkImageView and VkImageLayout, respectively (https://www.khronos.org/registry/vulkan/specs/1.1-extensions/html/vkspec.html#VUID-VkWriteDescriptorSet-descriptorType-00326)

然后，如果我只是尝试将绑定设置为空，则会得到以下结果：

Validation Layer: vkUpdateDescriptorSets: required parameter pDescriptorWrites[2].dstSet specified as VK_NULL_HANDLE

验证层：无法对尚未分配的VkDescriptorSet 0x0[]调用vkUpdateDescriptorSets()。

这就是现在的基本代码。这是定义描述符集的区域，以便更容易地看到正在发生的事情：

void Mesh::CreateDescriptorSets(VulkanRenderer& Renderer)
{
    BaseMesh::CreateDescriptorSets(Renderer, *GetDescriptorSetLayout(Renderer));

VkDescriptorImageInfo DiffuseMap = {};
DiffuseMap.imageLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;
DiffuseMap.imageView = TextureList[0].textureImageView;
DiffuseMap.sampler = TextureList[0].textureSampler;

VkDescriptorImageInfo SpecularMap = {};
SpecularMap.imageLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;
SpecularMap.imageView = TextureList[1].textureImageView;
SpecularMap.sampler = TextureList[1].textureSampler;

for (size_t i = 0; i < GetSwapChainImageCount(Renderer); i++)
{
    VkDescriptorBufferInfo PositionInfo = {};
    PositionInfo.buffer = uniformBuffers[i];
    PositionInfo.offset = 0;
    PositionInfo.range = sizeof(UniformBufferObject);

    VkDescriptorBufferInfo AmbiantLightInfo = {};
    AmbiantLightInfo.buffer = AmbientLightUniformBuffers[i];
    AmbiantLightInfo.offset = 0;
    AmbiantLightInfo.range = sizeof(AmbientLightUniformBuffer);

    VkDescriptorBufferInfo LightInfo = {};
    LightInfo.buffer = LighterUniformBuffers[i];
    LightInfo.offset = 0;
    LightInfo.range = sizeof(Lighter);

    std::array<WriteDescriptorSetInfo, 5>  WriteDescriptorInfo = {};

    WriteDescriptorInfo[0].DstBinding = 0;
    WriteDescriptorInfo[0].DstSet = descriptorSets[i];
    WriteDescriptorInfo[0].DescriptorType = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
    WriteDescriptorInfo[0].DescriptorBufferInfo = PositionInfo;

    WriteDescriptorInfo[1].DstBinding = 1;
    WriteDescriptorInfo[1].DstSet = descriptorSets[i];
    WriteDescriptorInfo[1].DescriptorType = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER;
    WriteDescriptorInfo[1].DescriptorImageInfo = DiffuseMap;

    WriteDescriptorInfo[2].DstBinding = 2;
    WriteDescriptorInfo[2].DstSet = descriptorSets[i];
    WriteDescriptorInfo[2].DescriptorType = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER;
    WriteDescriptorInfo[2].DescriptorImageInfo = SpecularMap;

    WriteDescriptorInfo[3].DstBinding = 3;
    WriteDescriptorInfo[3].DstSet = descriptorSets[i];
    WriteDescriptorInfo[3].DescriptorType = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
    WriteDescriptorInfo[3].DescriptorBufferInfo = AmbiantLightInfo;

    WriteDescriptorInfo[4].DstBinding = 4;
    WriteDescriptorInfo[4].DstSet = descriptorSets[i];
    WriteDescriptorInfo[4].DescriptorType = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
    WriteDescriptorInfo[4].DescriptorBufferInfo = LightInfo;

    Mesh::CreateDescriptorSetsData(Renderer, std::vector<WriteDescriptorSetInfo>(WriteDescriptorInfo.begin(), WriteDescriptorInfo.end()));
}

}

推荐答案

直到Vulkan1.2，Vulkan才认识到描述符为"空"的可能性。当创建描述符集时，描述符(大部分)未初始化。拥有一个带有未初始化描述符的集合是可以的，只要使用它的管道不会静态地使用描述符。由于您可能会尝试对具有漫反射贴图的对象和不具有漫反射贴图的对象使用相同的管线，因此着色器将根据您提供的变量从图像中读取。表示描述符的静态使用，因此您需要一个图像。

因此您根本不会为该描述符写入值。

当然，这需要1.2(或前述扩展)，以及请求该功能。

这篇关于有没有办法将VkDescriptorImageInfo设置为空，或者有某种方法跳过使用VkWriteDescriptorSet而不会出现Vulkan抱怨的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持编程学习网！