I have a situation in which a stencil buffer may be required in the rendering pass, but I will not “know” until the visa has completed the pass. Unfortunately, there is no way in Vulkan to modify attachments to the framebuffer as soon as the rendering stage is completed (for example, in D3D12). However, I found in the specification that there is a concept of “lazily allocated memory” used VK_MEMORY_PROPERTY_LAZILY_ALLOCATED_BITin memory allocation and VK_IMAGE_USAGE_TRANSIENT_ATTACHMENT_BITfor the surface.
VK_MEMORY_PROPERTY_LAZILY_ALLOCATED_BIT
VK_IMAGE_USAGE_TRANSIENT_ATTACHMENT_BIT
Unfortunately, it appears that none of the entries VkMemoryTypein VkPhysicalDeviceMemoryProperties(returned from vkGetPhysicalDeviceMemoryProperties) actually have this set of bits. Also, it looks like none of the API samples use these bits. This is just an unrealized function at the driver level, and do drivers often do not support this function?
VkMemoryType
VkPhysicalDeviceMemoryProperties
vkGetPhysicalDeviceMemoryProperties
I am using Vulkan SDK 1.0.5, Nvidia 356.45 driver.
. , , , , . . -, , / ( ). () , , , .
-, , , , . , . , .
, . g-. g-, . .
. . ? , , g- , g- . , ( ), , .
Vulkan , , , . , , , . , , -, .
/ , , . , . , , , TBR . ; .