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    • By khawk
      LunarG has released new Vulkan SDKs for Windows, Linux, and macOS based on the 1.1.73 header. The new SDK includes:
      New extensions: VK_ANDROID_external_memory_android_hardware_buffer VK_EXT_descriptor_indexing VK_AMD_shader_core_properties VK_NV_shader_subgroup_partitioned Many bug fixes, increased validation coverage and accuracy improvements, and feature additions Developers can download the SDK from LunarXchange at https://vulkan.lunarg.com/sdk/home.

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    • By khawk
      LunarG has released new Vulkan SDKs for Windows, Linux, and macOS based on the 1.1.73 header. The new SDK includes:
      New extensions: VK_ANDROID_external_memory_android_hardware_buffer VK_EXT_descriptor_indexing VK_AMD_shader_core_properties VK_NV_shader_subgroup_partitioned Many bug fixes, increased validation coverage and accuracy improvements, and feature additions Developers can download the SDK from LunarXchange at https://vulkan.lunarg.com/sdk/home.
    • By mark_braga
      I have a pretty good experience with multi gpu programming in D3D12. Now looking at Vulkan, although there are a few similarities, I cannot wrap my head around a few things due to the extremely sparse documentation (typical Khronos...)
      In D3D12 -> You create a resource on GPU0 that is visible to GPU1 by setting the VisibleNodeMask to (00000011 where last two bits set means its visible to GPU0 and GPU1)
      In Vulkan - I can see there is the VkBindImageMemoryDeviceGroupInfoKHR struct which you add to the pNext chain of VkBindImageMemoryInfoKHR and then call vkBindImageMemory2KHR. You also set the device indices which I assume is the same as the VisibleNodeMask except instead of a mask it is an array of indices. Till now it's fine.
      Let's look at a typical SFR scenario:  Render left eye using GPU0 and right eye using GPU1
      You have two textures. pTextureLeft is exclusive to GPU0 and pTextureRight is created on GPU1 but is visible to GPU0 so it can be sampled from GPU0 when we want to draw it to the swapchain. This is in the D3D12 world. How do I map this in Vulkan? Do I just set the device indices for pTextureRight as { 0, 1 }
      Now comes the command buffer submission part that is even more confusing.
      There is the struct VkDeviceGroupCommandBufferBeginInfoKHR. It accepts a device mask which I understand is similar to creating a command list with a certain NodeMask in D3D12.
      So for GPU1 -> Since I am only rendering to the pTextureRight, I need to set the device mask as 2? (00000010)
      For GPU0 -> Since I only render to pTextureLeft and finally sample pTextureLeft and pTextureRight to render to the swap chain, I need to set the device mask as 1? (00000001)
      The same applies to VkDeviceGroupSubmitInfoKHR?
      Now the fun part is it does not work  . Both command buffers render to the textures correctly. I verified this by reading back the textures and storing as png. The left texture is sampled correctly in the final composite pass. But I get a black in the area where the right texture should appear. Is there something that I am missing in this? Here is a code snippet too
      void Init() { RenderTargetInfo info = {}; info.pDeviceIndices = { 0, 0 }; CreateRenderTarget(&info, &pTextureLeft); // Need to share this on both GPUs info.pDeviceIndices = { 0, 1 }; CreateRenderTarget(&info, &pTextureRight); } void DrawEye(CommandBuffer* pCmd, uint32_t eye) { // Do the draw // Begin with device mask depending on eye pCmd->Open((1 << eye)); // If eye is 0, we need to do some extra work to composite pTextureRight and pTextureLeft if (eye == 0) { DrawTexture(0, 0, width * 0.5, height, pTextureLeft); DrawTexture(width * 0.5, 0, width * 0.5, height, pTextureRight); } // Submit to the correct GPU pQueue->Submit(pCmd, (1 << eye)); } void Draw() { DrawEye(pRightCmd, 1); DrawEye(pLeftCmd, 0); }  
    • By turanszkij
      Hi,
      I finally managed to get the DX11 emulating Vulkan device working but everything is flipped vertically now because Vulkan has a different clipping space. What are the best practices out there to keep these implementation consistent? I tried using a vertically flipped viewport, and while it works on Nvidia 1050, the Vulkan debug layer is throwing error messages that this is not supported in the spec so it might not work on others. There is also the possibility to flip the clip scpace position Y coordinate before writing out with vertex shader, but that requires changing and recompiling every shader. I could also bake it into the camera projection matrices, though I want to avoid that because then I need to track down for the whole engine where I upload matrices... Any chance of an easy extension or something? If not, I will probably go with changing the vertex shaders.
    • By Alexa Savchenko
      I publishing for manufacturing our ray tracing engines and products on graphics API (C++, Vulkan API, GLSL460, SPIR-V): https://github.com/world8th/satellite-oem
      For end users I have no more products or test products. Also, have one simple gltf viewer example (only source code).
      In 2016 year had idea for replacement of screen space reflections, but in 2018 we resolved to finally re-profile project as "basis of render engine". In Q3 of 2017 year finally merged to Vulkan API. 
       
       
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One thing to mention, you need those specific older Nvidia drivers, their newer ones on their site do not support Vulkan (yet?); or at least they didn't for me.

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FYI the AMD drivers are partially broken, at least on my 290X. There's something wrong with their ICD implementation, there are posts on the internal AMD developer forum about the issue.

 

EDIT: Never mind. I went to go check on the status of this and it looks like AMD has issued a hotfix.

Edited by InvalidPointer

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https://github.com/SaschaWillems/Vulkan

 

Is it just me or are most of the samples doing a ton of unnecessary waiting? 

 

With the exception maybe doing something quick and dirty, special blocking loads, or maybe something fancy I can't think of at the moment, I kind of assume one wouldn't want to call vkDeviceWaitIdle or vkQueueWaitIdle very frequently. Right? But they seem littered everywhere.

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Is it just me or are most of the samples doing a ton of unnecessary waiting? 

 

With the exception maybe doing something quick and dirty, special blocking loads, or maybe something fancy I can't think of at the moment, I kind of assume one wouldn't want to call vkDeviceWaitIdle or vkQueueWaitIdle very frequently. Right? But they seem littered everywhere.

 

It's a hell of a lot easier than setting up the infrastructure for double (or more) buffering, where you need to ensure that you don't change/delete things that are being used for the previous frame.  You still need to issue a wait every 2 frames for double buffering (3 for triple buffering, and so on), but in practice, it's just there as a safeguard for pathological scenarios and should typically be a no-op.

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