vsgoffscreenshot exports the image data to 0

[idealist-dg]

Hi, I am developing a project using vsg and I need to use off-screen rendering, i.e. provide a vsg::Node to return a PNG-like image.
I started from vsgoffscreenshot, I use teapot.vsgt, but after pressing s the vsgt file is saved with all the picture data 0, did I miss something?
The export format of objects in vsg is vsgt. If I use vsgXchange, can I export PNG directly?

[robertosfield]

Looks like there is a regression in vsgoffscreenshot, I have just run:

vsgoffscreenshot models/teapot.vsgt -d

And get the following errors:

UID-vkCmdDrawIndexed-renderPass-02684(ERROR / SPEC): msgNum: -1934215230 - Validation Error: [ VUID-vkCmdDrawIndexed-renderPass-02684 ] Object 0: handle = 0x5ef1450dfd40, type = VK_OBJECT_TYPE_COMMAND_BUFFER; Object 1: handle = 0xfab64d0000000002, type = VK_OBJECT_TYPE_RENDER_PASS; Object 2: handle = 0x3a6cbb0000000025, type = VK_OBJECT_TYPE_PIPELINE; Object 3: handle = 0xec4bec000000000b, type = VK_OBJECT_TYPE_RENDER_PASS; | MessageID = 0x8cb637c2 | vkCmdDrawIndexed():  pSubpasses[0].pColorAttachments[0].attachment is incompatible between VkRenderPass 0xfab64d0000000002[] (from VkCommandBuffer 0x5ef1450dfd40[]) and VkRenderPass 0xec4bec000000000b[] (from VkPipeline 0x3a6cbb0000000025[]), pAttachments[0].format (VK_FORMAT_B8G8R8A8_SRGB) != pAttachments[0].format (VK_FORMAT_R8G8B8A8_UNORM). The Vulkan spec states: The current render pass must be compatible with the renderPass member of the VkGraphicsPipelineCreateInfo structure specified when creating the VkPipeline bound to VK_PIPELINE_BIND_POINT_GRAPHICS (https://vulkan.lunarg.com/doc/view/1.3.290.0/linux/1.3-extensions/vkspec.html#VUID-vkCmdDrawIndexed-renderPass-02684)
    Objects: 4
        [0] 0x5ef1450dfd40, type: 6, name: NULL
        [1] 0xfab64d0000000002, type: 18, name: NULL
        [2] 0x3a6cbb0000000025, type: 19, name: NULL
        [3] 0xec4bec000000000b, type: 18, name: NULL
VUID-vkCmdDrawIndexed-renderPass-02684(ERROR / SPEC): msgNum: -1934215230 - Validation Error: [ VUID-vkCmdDrawIndexed-renderPass-02684 ] Object 0: handle = 0x5ef1450dfd40, type = VK_OBJECT_TYPE_COMMAND_BUFFER; Object 1: handle = 0xfab64d0000000002, type = VK_OBJECT_TYPE_RENDER_PASS; Object 2: handle = 0x3a6cbb0000000025, type = VK_OBJECT_TYPE_PIPELINE; Object 3: handle = 0xec4bec000000000b, type = VK_OBJECT_TYPE_RENDER_PASS; | MessageID = 0x8cb637c2 | vkCmdDrawIndexed():  pSubpasses[0].pColorAttachments[0].attachment is incompatible between VkRenderPass 0xfab64d0000000002[] (from VkCommandBuffer 0x5ef1450dfd40[]) and VkRenderPass 0xec4bec000000000b[] (from VkPipeline 0x3a6cbb0000000025[]), pAttachments[0].format (VK_FORMAT_B8G8R8A8_SRGB) != pAttachments[0].format (VK_FORMAT_R8G8B8A8_UNORM). The Vulkan spec states: The current render pass must be compatible with the renderPass member of the VkGraphicsPipelineCreateInfo structure specified when creating the VkPipeline bound to VK_PIPELINE_BIND_POINT_GRAPHICS (https://vulkan.lunarg.com/doc/view/1.3.290.0/linux/1.3-extensions/vkspec.html#VUID-vkCmdDrawIndexed-renderPass-02684)
    Objects: 4
        [0] 0x5ef1450dfd40, type: 6, name: NULL
        [1] 0xfab64d0000000002, type: 18, name: NULL
        [2] 0x3a6cbb0000000025, type: 19, name: NULL
        [3] 0xec4bec000000000b, type: 18, name: NULL

I also get black image when I press 's' then run 'vsgviewer screenshot.vsgt'.

My best guess is one of the settings is incompatible with the new default of sRGB framebuffer that was merged with v.1.1.10 dev release. I will look into this.

W.r.t png write is support be vsgXchange::stbi, you can list the supported features using:

$ vsgconv --features vsgXchange::stbi

vsgXchange::stbi provides support for 9 extensions, and 0 protocols.
    Extensions      Supported ReaderWriter methods
    ----------      ------------------------------
    .bmp            read(vsg::Path, ..) read(std::istream, ..) read(uint8_t* ptr, size_t size, ..) write(vsg::Path, ..) write(std::ostream, ..) 
    .jpe            read(vsg::Path, ..) read(std::istream, ..) read(uint8_t* ptr, size_t size, ..) write(vsg::Path, ..) write(std::ostream, ..) 
    .jpeg           read(vsg::Path, ..) read(std::istream, ..) read(uint8_t* ptr, size_t size, ..) write(vsg::Path, ..) write(std::ostream, ..) 
    .jpg            read(vsg::Path, ..) read(std::istream, ..) read(uint8_t* ptr, size_t size, ..) write(vsg::Path, ..) write(std::ostream, ..) 
    .pgm            read(vsg::Path, ..) read(std::istream, ..) read(uint8_t* ptr, size_t size, ..) 
    .png            read(vsg::Path, ..) read(std::istream, ..) read(uint8_t* ptr, size_t size, ..) write(vsg::Path, ..) write(std::ostream, ..) 
    .ppm            read(vsg::Path, ..) read(std::istream, ..) read(uint8_t* ptr, size_t size, ..) 
    .psd            read(vsg::Path, ..) read(std::istream, ..) read(uint8_t* ptr, size_t size, ..) 
    .tga            read(vsg::Path, ..) read(std::istream, ..) read(uint8_t* ptr, size_t size, ..) write(vsg::Path, ..) write(std::ostream, ..) 

    vsg::Options::Value  type
    -------------------  ----
    image_format         vsg::CoordinateSpace
    jpeg_quality         int

To test it I ran vsgscreenshot example, then pressed 's' then converted to png with:

vsgconv screenshot.vsgt screenshot.png

The final screenshot.png works fine when loading back into vsgviewer.

[robertosfield]

I have created Issue #1398 for this regression.

[robertosfield]

I have fixed the issues with the vsgoffscreenshot example:

vsg-dev/vsgExamples@ed8e2e7

[dov]

I tested the new vsgoffscreenshot last night, and unfortunately there are still problems with it.

See: vsg-dev/vsgExamples#349