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Siggraph 2016
Tristan Lorach Manager of Developer Technology Group, NVIDIA US
7/25/2016
VULKAN AND NVIDIA:
THE ESSENTIALS
2
ANALOGY ON GRAPHIC APIS
(getting ready for my 7 years old son’s questions on my job…)
Lego Kit Derby KitCar Toy
3
Analogy
Different Valid Approaches
Fixed-function OpenGL Modern AZDO OpenGL with
Programmable Shaders
Vulkan
(adult supe...
4
WHAT IS VULKAN ?
…It’s a modern API
• Designed and maintained by Khronos Group
• Designed for high performance on render...
5
Beneficial Vulkan Scenarios
Is your graphics
work CPU bound?
Can your graphics
creation be parallelized?
start
yes
Vulka...
6
Beneficial Vulkan Scenarios
Is your graphics
work CPU bound?
Can your graphics
creation be parallelized?
start
yes
Vulka...
7
Unlikely to Benefit
Scenarios to Reconsider Coding to Vulkan
1. Need for compatibility to pre-Vulkan platforms
2. Heavil...
8
memory GPU
BIG PICTURE –OPENGL CASE
Vertex Puller (IA)
Vertex Shader
TCS (Tessellation)
TES (Tessellation)
Tessellator
G...
9
Application
memory GPU
BIG PICTURE – VULKAN
Vertex Puller (IA)
Vertex Shader
TCS (Tessellation)
TES (Tessellation)
Tesse...
10
Instance
VULKAN COMPONENTS
Device
Queue
Command-buffer
…
Graphics pipeline
Descriptor-Set
Framebuffer Render-Pass
Image...
11
Instance
Device
VULKAN COMPONENTS
Device(s)
Queue(s)
Command-buffer
…
Graphics pipeline
Descriptor-Set
Framebuffer Rend...
12
Device
Queue
Command-buffer
…
Graphics pipeline
Descriptor-Set
Framebuffer Render-Pass
Image
Memory
2ndary Command-buff...
13
HOW DOES IT LOOK ?
Instance creation
Layer properties
Extension properties
14
HOW DOES IT LOOK ?
Instance creation
etc
Get Instance-Extension’s functions
15
Device
Queue
Command-buffer
…
Graphics pipeline
Descriptor-Set
Framebuffer Render-Pass
Image
Memory
2ndary Command-buff...
16
NVIDIA’S VULKAN CAPABILITIES
Properties listed from Physical Device
NVIDIA is almost full featured
Top to bottom: from ...
17
NVIDIA’S VULKAN CAPABILITIESGeForce GTX 980
Tegra X1 & K1
18
HOW DOES IT LOOK ?
Device creation – enumerate physical devices; gather properties
20
HOW DOES IT LOOK ?
Device creation – Create the device (!)
21
Device
Queue
Command-buffer
…
Graphics pipeline
Descriptor-Set
Framebuffer Render-Pass
Image
Memory
2ndary Command-buff...
22
Device
Queue
Command-buffer
…
Graphics pipeline
Descriptor-Set
Framebuffer Render-Pass
Image
Memory
2ndary Command-buff...
23
HOW DOES IT LOOK ?
Queue(s)
24
Device
Queue
Command-buffer
…
Graphics pipeline
Descriptor-Set
Framebuffer Render-Pass
Image
Memory
2ndary Command-buff...
25
SYNCHRONIZATION
events and barriers
used to synchronize work within a command
buffer or sequence of command buffers
sub...
26
COMMAND-BUFFERS
Vulkan Rendering  Command-Buffers
Close to what GPU will get at Front-End (FIFO)
Minor translation & o...
27
Thread 1
(Busy)
Update Work
Feed Cmd
Buffers
cmd. Buffer Pool
Create 2dary Cmd Buffer
Give out Cmd Buffers
COMMAND-BUFF...
28
Must not recycle a CommandBuffer for rewriting until it is no longer in flight (In flight
== GPU still consuming it on ...
29
Frame NFrame N-1
Threads can have more than 1 Command Pool
Ring-buffer: One Command-Pool per Frame
when the frame is no...
30
HOW DOES IT LOOK ?
Command-Buffers
Note: helpers (structs
wrappers) to use
Constructors & functors for
compact data dec...
31
Device
Queue
Command-buffer
…
Graphics pipeline
Descriptor-Set
Framebuffer Render-Pass
Image
Memory
2ndary Command-buff...
32
Device
Queue
Command-buffer
…
Graphics pipeline
Descriptor-Set
Framebuffer Render-Pass
Image
Memory
2ndary Command-buff...
33
Device
Queue
Command-buffer
…
Graphics pipeline
Descriptor-Set
Framebuffer Render-Pass
Image
Memory
2ndary Command-buff...
34
HOW DOES IT LOOK ?
Graphics pipeline - setup
35
HOW DOES IT LOOK ?
Graphics pipeline creation (compact notation)
36
Device
Queue
Command-buffer
…
Graphics pipeline
Descriptor-Set
Framebuffer Render-Pass
Image
Memory
2ndary Command-buff...
37
Device
Queue
Command-buffer
…
Graphics pipeline
Descriptor-Set
Framebuffer Render-Pass
Image
Memory
2ndary Command-buff...
38
COMMAND-BUFFERS: UPDATE/PUSH CONSTANTS
2 more ways to update constants/uniforms for Shaders from
the Command-Buffer
Upd...
39
HOW DOES IT LOOK ?
Buffers – copy data in a buffer
• Create Buffer
• Create staging buffer
• Bind objects to some memor...
40
Device
Queue
Command-buffer
…
Graphics pipeline
Descriptor-Set
Framebuffer Render-Pass
Image
Memory
2ndary Command-buff...
41
Device
Queue
Command-buffer
…
Graphics pipeline
Descriptor-Set
Framebuffer Render-Pass
Image
Memory
2ndary Command-buff...
42
HOW DOES IT LOOK ?
Way more complex than OpenGL !
• Load image
• Create an Image
(1D/2D/3D/Cube…)
• Create an Image-Vie...
43
HOW DOES IT LOOK ?
Simple texture creation
44
Device
Queue
Command-buffer
…
Graphics pipeline
Descriptor-Set
Framebuffer Render-Pass
Image
Memory
2ndary Command-buff...
45
Device
Queue
Command-buffer
…
Graphics pipeline
Descriptor-Set
Framebuffer Render-Pass
Image
Memory
2ndary Command-buff...
46
Device
Queue
Command-buffer
…
Graphics pipeline
Descriptor-Set
Framebuffer Render-Pass
Image
Memory
2ndary Command-buff...
47
HOW DOES IT LOOK ?
Descriptor Set - initialization
48
HOW DOES IT LOOK ?
Descriptor Set – using it
49
DESCRIPTOR SETS AND MULTI-THREADING
Thread 1
Update Work
Update
resources
in Desc. Sets
Descriptor Pool
Allocate Desc. ...
50
Device
Queue
Command-buffer
…
Graphics pipeline
Descriptor-Set
Framebuffer Render-Pass
Image
Memory
2ndary Command-buff...
51
Device
Queue
Command-buffer
…
Graphics pipeline
Descriptor-Set
Framebuffer Render-Pass
Image
Memory
2ndary Command-buff...
52
HOW DOES IT LOOK ?
Renderpass Creation (‘compacted’ notation for Vulkan structures)
53
HOW DOES IT LOOK ?
Framebuffer Creation and use
54
Device
Queue
Command-buffer
…
Graphics pipeline
Descriptor-Set
Framebuffer Render-Pass
Image
Memory
2ndary Command-buff...
55
Device
Queue
Command-buffer
…
Graphics pipeline
Descriptor-Set
Framebuffer Render-Pass
Image
Memory
2ndary Command-buff...
56
Device
Queue
Command-buffer
…
Graphics pipeline
Descriptor-Set
Framebuffer Render-Pass
Image
Memory
2ndary Command-buff...
57
RESOURCE MANAGEMENT
Allocation and Sub allocation
HEAP supporting A,B HEAP supporting B
Allocation Type A Allocation Ty...
58
RESOURCE MANAGEMENT
#HappyGPU
Memory Allocation
Buffer
UniformVertexIndex
Memory Allocation
Buffer
Index Vertex
Buffer
...
59
HOW DOES IT LOOK ?
Binding Memory to Objects – Simple use-case
Mem properties previously gathered at init time
60
SHADERS
Vulkan uses SPIR-V passed directly to the driver
Can be compiled from GLSL Via glslang or LunarG’s glslangValid...
61
SHADERS
Multiple entry points can be defined in a single Spir-V
shader-module
Prevents redundant code: shader module us...
62
VULKAN WINDOW SYSTEM INTEGRATION (WSI)
WSI manages the ownership of images via a swap chain
One image is presented whil...
63
NVIDIA OPENGL VULKAN INTEROP
Alternative to WSI: GL_NV_draw_vulkan_image
Create an OpenGL Context and all the usual th...
64
HOW DOES IT LOOK ?
GL_NV_draw_vulkan_image
Initialize…
65
HOW DOES IT LOOK ?
GL_NV_draw_vulkan_image
Submit commands to Queue with semaphores
Backbuffer Blit
66
PRE-REQUISITES TO WORK WITH VULKAN
Lunar-G (http://lunarg.com/ )
Vulkan Loader (+Source code)
Tools: Spir-V compiler fo...
67
RECAP’ ON NVIDIA-SPECIFIC FEATURES
Compatible GPUs for Vulkan: Kepler and Higher; Shield Tablet; Shield Android TV
VK_N...
68
NSIGHT FOR VULKAN
69
RECAP’ ON VULKAN PHILOSOPHY
Validate as much as possible up-front (DescriptorSets; Pipelines…)
The driver doesn’t waste...
70
FEW WORDS ON VKCPP PROJECT
C++11 to the rescue
• Open-Source Project of a C++11 overlay for Vulkan: became Khronos-offc...
71
VKCPP PROJECT
Two C++ based layers
Autogenerated ‚low-level‘ layer using vulkan.xml
• Type safety
• Syntactic sugar
• L...
72
NATIVE VULKAN VS. VKCPP CODE
Native Vulkan: ~750 lines vkCPP: ~200 lines
73
REFERENCES
Vulkan info from NVIDIA:
https://developer.nvidia.com/Vulkan
https://developer.nvidia.com/vulkan-graphics-ap...
THANK YOU
HTTPS://DEVELOPER.NVIDIA.COM/DESIGNWORKS
TLORACH@NVIDIA.COM
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Siggraph 2016 - Vulkan and nvidia : the essentials

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This presentation introduces Vulkan components, what you must know to start using this new API. And what you must know when using it on NVIDIA hardware

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Siggraph 2016 - Vulkan and nvidia : the essentials

  1. 1. Siggraph 2016 Tristan Lorach Manager of Developer Technology Group, NVIDIA US 7/25/2016 VULKAN AND NVIDIA: THE ESSENTIALS
  2. 2. 2 ANALOGY ON GRAPHIC APIS (getting ready for my 7 years old son’s questions on my job…) Lego Kit Derby KitCar Toy
  3. 3. 3 Analogy Different Valid Approaches Fixed-function OpenGL Modern AZDO OpenGL with Programmable Shaders Vulkan (adult supervision required!)(booring…) (cool... Messes-up the bedroom)
  4. 4. 4 WHAT IS VULKAN ? …It’s a modern API • Designed and maintained by Khronos Group • Designed for high performance on rendering and compute • [Extremely] low level : no more “baby-sitting” from our driver • Manage yourself memory, resource updates; batching; scheduling… • [Extremely] verbose : Lots of structures to fill with parameters • close to DX12 design… • Opposite of OpenGL: Multi-threading friendly : Vulkan will especially shine if multi-threading used • But still generic enough to work on many HW vendors & platforms
  5. 5. 5 Beneficial Vulkan Scenarios Is your graphics work CPU bound? Can your graphics creation be parallelized? start yes Vulkan friendly yes Your graphics platform is fixed You’ll do whatever it takes to squeeze out Max perf. You put a premium on avoiding hitches You can manage your graphics resource allocations yes yes yes yes
  6. 6. 6 Beneficial Vulkan Scenarios Is your graphics work CPU bound? Can your graphics creation be parallelized? start yes Vulkan friendly yes Your graphics platform is fixed You’ll do whatever it takes to squeeze out Max perf. You put a premium on avoiding hitches You can manage your graphics resource allocations yes yes yes yes Tired with OpenGL (state-machine) or even D3D ? Want to learn new stuff ? Spend lots of time coding ? No sleep ? Kinda… (it’s a Yes) Alright… (Yes)
  7. 7. 7 Unlikely to Benefit Scenarios to Reconsider Coding to Vulkan 1. Need for compatibility to pre-Vulkan platforms 2. Heavily GPU-bound application 3. Heavily CPU-bound application due to non-graphics work 4. Single-threaded application, unlikely to change 5. App can target middle-ware engine, avoiding 3D graphics API dependencies • Consider using an engine targeting Vulkan, instead of dealing with Vulkan yourself Good News in any case: NVIDIA OpenGL driver is great and will always be there !
  8. 8. 8 memory GPU BIG PICTURE –OPENGL CASE Vertex Puller (IA) Vertex Shader TCS (Tessellation) TES (Tessellation) Tessellator Geometry Shader Transform Feedback Rasterization Fragment Shader Per-Fragment Ops Framebuffer Tr. Feedback buffer Uniform Block Texture Fetch Image Load/Store Atomic Counter Shader Storage Element buffer (EBO) Draw Indirect Buffer Vertex Buffer (VBO) Front-End (decoder) OpenGL Driver Application FBO resources (Textures / RB) OpenGL Commands Cmd bundles Push-Buffer (FIFO) cmds OpenGL resources Resources Graphics pipeline States Dependencies Heap . .
  9. 9. 9 Application memory GPU BIG PICTURE – VULKAN Vertex Puller (IA) Vertex Shader TCS (Tessellation) TES (Tessellation) Tessellator Geometry Shader Transform Feedback Rasterization Fragment Shader Per-Fragment Ops Framebuffer Tr. Feedback buffer Uniform Block Texture Fetch Image Load/Store Atomic Counter Shader Storage Element buffer (EBO) Draw Indirect Buffer Vertex Buffer (VBO) Front-End (decoder) OpenGL Driver FBO resources (Textures / RB) Cmd bundles Push-Buffer (FIFO) cmds Minimal memory management Fewer translation, Validation checks And internal mgt Resources Pipeline States Cmd-buffers / queues Dependencies Heap Render Passes Descriptor Sets
  10. 10. 10 Instance VULKAN COMPONENTS Device Queue Command-buffer … Graphics pipeline Descriptor-Set Framebuffer Render-Pass Image Memory 2ndary Command-buffer … … Buffer Image View Buffer Sampler Image View Begin Render-Pass Bind Graphics-pipeline Bind Vertex/Idx Buffer(s) Bind Descriptor-Set(s) Draw… End Render-Pass Execute Commands Update Buffer Set misc. dynamic states Barrier synchronization Heap Cmd.Buffer Pool DescriptorSet Pool
  11. 11. 11 Instance Device VULKAN COMPONENTS Device(s) Queue(s) Command-buffer … Graphics pipeline Descriptor-Set Framebuffer Render-Pass Image Memory 2ndary Command-buffer … … Buffer Image View Buffer Sampler Image View Begin Render-Pass Bind Graphics-pipeline Bind Vertex/Idx Buffer(s) Bind Descriptor-Set(s) Draw… End Render-Pass Execute Commands Update Buffer Set misc. dynamic states Barrier synchronization Heap Cmd.Buffer Pool DescriptorSet Pool Command-buffer
  12. 12. 12 Device Queue Command-buffer … Graphics pipeline Descriptor-Set Framebuffer Render-Pass Image Memory 2ndary Command-buffer … … Buffer Image View Buffer Sampler Image View Begin Render-Pass Bind Graphics-pipeline Bind Vertex/Idx Buffer(s) Bind Descriptor-Set(s) Draw… End Render-Pass Execute Commands Update Buffer Set misc. dynamic states Barrier synchronization Heap Cmd.Buffer Pool DescriptorSet Pool Command-buffer VULKAN OBJECTS: DEVICE Instance Device(s) Instance ~~ OpenGL Context Instance-Layers • Intercepting API calls for misc. purposes • Many layers available (api-dump; core/std/parms validation; screenshot…) Instance-Specific Extensions • KHR_Surface (for Swap-chains) • EXT_debug_report • … Exposes some Devices…
  13. 13. 13 HOW DOES IT LOOK ? Instance creation Layer properties Extension properties
  14. 14. 14 HOW DOES IT LOOK ? Instance creation etc Get Instance-Extension’s functions
  15. 15. 15 Device Queue Command-buffer … Graphics pipeline Descriptor-Set Framebuffer Render-Pass Image Memory 2ndary Command-buffer … … Buffer Image View Buffer Sampler Image View Begin Render-Pass Bind Graphics-pipeline Bind Vertex/Idx Buffer(s) Bind Descriptor-Set(s) Draw… End Render-Pass Execute Commands Update Buffer Set misc. dynamic states Barrier synchronization Heap Cmd.Buffer Pool DescriptorSet Pool Command-buffer Can have many … VULKAN OBJECTS: DEVICE Device(s) VkPhysicalDevice • Capabilities • Memory Management • Queues • Objects • Buffers • Images • Sync Primitives
  16. 16. 16 NVIDIA’S VULKAN CAPABILITIES Properties listed from Physical Device NVIDIA is almost full featured Top to bottom: from GeForce, Quadro down to Tegra Check http://vulkan.gpuinfo.org/listreports.php
  17. 17. 17 NVIDIA’S VULKAN CAPABILITIESGeForce GTX 980 Tegra X1 & K1
  18. 18. 18 HOW DOES IT LOOK ? Device creation – enumerate physical devices; gather properties
  19. 19. 20 HOW DOES IT LOOK ? Device creation – Create the device (!)
  20. 20. 21 Device Queue Command-buffer … Graphics pipeline Descriptor-Set Framebuffer Render-Pass Image Memory 2ndary Command-buffer … … Buffer Image View Buffer Sampler Image View Begin Render-Pass Bind Graphics-pipeline Bind Vertex/Idx Buffer(s) Bind Descriptor-Set(s) Draw… End Render-Pass Execute Commands Update Buffer Set misc. dynamic states Barrier synchronization Heap Cmd.Buffer Pool DescriptorSet Pool Queue VULKAN COMPONENTS
  21. 21. 22 Device Queue Command-buffer … Graphics pipeline Descriptor-Set Framebuffer Render-Pass Image Memory 2ndary Command-buffer … … Buffer Image View Buffer Sampler Image View Begin Render-Pass Bind Graphics-pipeline Bind Vertex/Idx Buffer(s) Bind Descriptor-Set(s) Draw… End Render-Pass Execute Commands Update Buffer Set misc. dynamic states Barrier synchronization Heap Cmd.Buffer Pool DescriptorSet Pool Command-buffer QUEUES Command queue was hidden in OpenGL Context… now explitly declared Multiple threads can submit work to a queue (or queues)! Queues accept GPU work via CommandBuffer submissions few operations available around Queues:, “submit work” and “wait for idle” Queue submissions can include sync primitives for the queue to: Wait upon before processing the submitted work Signal when the work in this submission is completed Queue “families” can accept different types of work, e.g. NVIDIA exposes 2 families: 1+16 Queues 16 for all available types of work 1 for transfer operations only (Copy Engine) Queue
  22. 22. 23 HOW DOES IT LOOK ? Queue(s)
  23. 23. 24 Device Queue Command-buffer … Graphics pipeline Descriptor-Set Framebuffer Render-Pass Image Memory 2ndary Command-buffer … … Buffer Image View Buffer Sampler Image View Begin Render-Pass Bind Graphics-pipeline Bind Vertex/Idx Buffer(s) Bind Descriptor-Set(s) Draw… End Render-Pass Execute Commands Update Buffer Set misc. dynamic states Barrier synchronization Heap Cmd.Buffer Pool DescriptorSet Pool Command-buffer … 2ndary Command-buffer … … Begin Render-Pass Bind Graphics-pipeline Bind Vertex/Idx Buffer(s) Bind Descriptor-Set(s) Draw… End Render-Pass Execute Commands Update Buffer Set misc. dynamic states Barrier synchronization Cmd.Buffer Pool VULKAN COMPONENTS
  24. 24. 25 SYNCHRONIZATION events and barriers used to synchronize work within a command buffer or sequence of command buffers submitted to a single queue semaphores used to synchronize work across queues or across coarse-grained submissions to a single queue fences used to synchronize work between the device and the host. Device Queue Cmd-buffer Host barrier event Queue Cmd-buffer Queue Cmd-buffer event Semaphores Fences
  25. 25. 26 COMMAND-BUFFERS Vulkan Rendering  Command-Buffers Close to what GPU will get at Front-End (FIFO) Minor translation & optimization from the Driver prior to sending to the GPU Each can be created either for one shot or for multiple frames/submissions Cannot Cmd-Buffers from GPU (command-lists can): API calls to vkCmd…() between Begin & End Multi-threading friendly (!) Primary Cmd-Buffer can call many many 2ndary Cmd-Buffers 2ndary Command- buffer … 2ndary Command- buffer … Primary Cmd-buffer … 2ndary Cmd-buffer … … Begin Render-Pass Bind Graphics-pipeline Bind Vertex/Idx Buffer(s) Bind Descriptor-Set(s) Draw… End Render-Pass Execute Commands Update Buffer Set misc. dynamic states Barrier synchronization Cmd.Buffer Pool
  26. 26. 27 Thread 1 (Busy) Update Work Feed Cmd Buffers cmd. Buffer Pool Create 2dary Cmd Buffer Give out Cmd Buffers COMMAND-BUFFERS AND MULTI-THREADING Main thread (Busy) Game Work Thread Coordination Swapping Collect Submit to Q cmd. Buffer Pool Create 1ary Cmd Buffer 1ary Cmd calls 2dary ones Thread 3 (Busy) Update Work Feed Cmd Buffers cmd. Buffer Pool Create 2dary Cmd Buffer Give out Cmd Buffers Thread 4 (Busy) Update Work Feed Cmd Buffers cmd. Buffer Pool Create 2dary Cmd Buffer Give out Cmd Buffers Thread 2 (Busy) Update Work Feed Cmd Buffers cmd. Buffer Pool Create 2dary Cmd Buffer Give out Cmd Buffers Command Buffer Pool local to the thread To prevent conflicts in concurrent access
  27. 27. 28 Must not recycle a CommandBuffer for rewriting until it is no longer in flight (In flight == GPU still consuming it on its side) But we can’t flush the queue each frame: would break parallelism ! VkFences can be provided with a queue submission to test when a command buffer is ready to be recycled COMMAND BUFFER THREAD SAFETY App Submissions to the Queue GPU Consumes Queue Fence A CommandBuffer CommandBuffer CommandBuffer Fence B CommandBuffer CommandBuffer Fence A Signaled to App Rewrite command buffer CommandBuffer
  28. 28. 29 Frame NFrame N-1 Threads can have more than 1 Command Pool Ring-buffer: One Command-Pool per Frame when the frame is no longer in flight (Using Fences): simply reset the whole Pool Frame N-2 THREADS AND COMMAND POOLS Thread 1 CommandPool Command Buffer Command Buffer CommandPool Command Buffer Command Buffer CommandPool Command Buffer Command Buffer Thread 2 CommandPool Command Buffer Command Buffer CommandPool Command Buffer Command Buffer CommandPool Command Buffer Command Buffer
  29. 29. 30 HOW DOES IT LOOK ? Command-Buffers Note: helpers (structs wrappers) to use Constructors & functors for compact data declaration See NVK.h/cpp in https://github.com/nvpro- samples
  30. 30. 31 Device Queue Command-buffer … Graphics pipeline Descriptor-Set Framebuffer Render-Pass Image Memory 2ndary Command-buffer … … Buffer Image View Buffer Sampler Image View Begin Render-Pass Bind Graphics-pipeline Bind Vertex/Idx Buffer(s) Bind Descriptor-Set(s) Draw… End Render-Pass Execute Commands Update Buffer Set misc. dynamic states Barrier synchronization Heap Cmd.Buffer Pool DescriptorSet Pool Command-buffer VULKAN COMPONENTS Graphics pipeline
  31. 31. 32 Device Queue Command-buffer … Graphics pipeline Descriptor-Set Framebuffer Render-Pass Image Memory 2ndary Command-buffer … … Buffer Image View Buffer Sampler Image View Begin Render-Pass Bind Graphics-pipeline Bind Vertex/Idx Buffer(s) Bind Descriptor-Set(s) Draw… End Render-Pass Execute Commands Update Buffer Set misc. dynamic states Barrier synchronization Heap Cmd.Buffer Pool DescriptorSet Pool Command-buffer Descriptor-set LayoutDescriptor-set Layout GRAPHICS PIPELINE Snapshot of all States Including Shaders Pre-compiled & Immutable Ideally: done at Initialization time Ok at render-time *if* using the Pipeline-Cache Prevents validation overhead during rendering loop Some Render-states can be excluded from it: they become “Dynamic” States Graphics pipeline Pipeline-layout Descriptor-set Layout Shader Stage Vertex Input Tess. State Viewport State Rasterizations State Multi-Sample State Depth & Stencil State Color Blend State Optional Dynamic States Viewport Scissor Blend const Stencil Ref Depth Bounds Depth Bias Shader Module Shader Stage Rasterizations State • depthClipEnable • rasterizerDiscardEnable • fillMode • cullMode • frontFace • depthBiasEnable • depthBias • depthBiasClamp • slopeScaledDepthBias • lineWidth Pipeline cache
  32. 32. 33 Device Queue Command-buffer … Graphics pipeline Descriptor-Set Framebuffer Render-Pass Image Memory 2ndary Command-buffer … … Buffer Image View Buffer Sampler Image View Begin Render-Pass Bind Graphics-pipeline Bind Vertex/Idx Buffer(s) Bind Descriptor-Set(s) Draw… End Render-Pass Execute Commands Update Buffer Set misc. dynamic states Barrier synchronization Heap Cmd.Buffer Pool DescriptorSet Pool Command-buffer Descriptor-set LayoutDescriptor-set Layout GRAPHICS PIPELINE Graphics Pipeline must be consistent with shaders No “introspection”, so everything known & prepared in advance Vertex Input: tells how Attributes: Locations are attached to which Vertex Buffer at which offset Pipeline Layout: Tells how to map Sets and Bindings for the shaders at each stage (Vtx, Fragment, Geom…) Graphics pipeline Pipeline-layout Descriptor-set Layout Shader Stage Vertex Input Shader Module GLSL Code layout(std140, set= 0 , binding= 0) uniform A { ... }; layout(std140, set= 0 , binding= 1) uniform B { … }; layout(std140, set= 1 , binding= 2) uniform C { … }; … layout(location=0) in vec3 pos; layout(location=1) in vec3 N; … void main() { … Spir-Vcompiled Descriptor-Set(s) Descriptor-Sets for …
  33. 33. 34 HOW DOES IT LOOK ? Graphics pipeline - setup
  34. 34. 35 HOW DOES IT LOOK ? Graphics pipeline creation (compact notation)
  35. 35. 36 Device Queue Command-buffer … Graphics pipeline Descriptor-Set Framebuffer Render-Pass Image Memory 2ndary Command-buffer … … Buffer Image View Buffer Sampler Image View Begin Render-Pass Bind Graphics-pipeline Bind Vertex/Idx Buffer(s) Bind Descriptor-Set(s) Draw… End Render-Pass Execute Commands Update Buffer Set misc. dynamic states Barrier synchronization Heap Cmd.Buffer Pool DescriptorSet Pool Command-buffer Buffer Buffer VULKAN COMPONENTS
  36. 36. 37 Device Queue Command-buffer … Graphics pipeline Descriptor-Set Framebuffer Render-Pass Image Memory 2ndary Command-buffer … … Buffer Image View Buffer Sampler Image View Begin Render-Pass Bind Graphics-pipeline Bind Vertex/Idx Buffer(s) Bind Descriptor-Set(s) Draw… End Render-Pass Execute Commands Update Buffer Set misc. dynamic states Barrier synchronization Heap Cmd.Buffer Pool DescriptorSet Pool Command-buffer BUFFERS Highly Heterogenous. Most often used for: Index/Vertex Buffers Uniform Buffers (Matrices, material parameters…) Vulkan Object: Must be bound to some Device Memory Can be CPU accessible memory (mappable) Can be CPU cached Can be GPU accessible only: need a “Staging Buffer” to write into it But most Efficient (More on Device Memory later…)
  37. 37. 38 COMMAND-BUFFERS: UPDATE/PUSH CONSTANTS 2 more ways to update constants/uniforms for Shaders from the Command-Buffer Update-Buffer: prior to Render-Pass: can target any Buffer bound by Descriptor Sets Push-Constants: targets a dedicated section in GLSL/SpirV New values appended “in-band”: in the Command-Buffer Efficient; but good for small amount of values Primary Cmd-buffer … Begin Render-Pass Draw… vkCmdPushConstants vkCmdUpdateBuffer() layout(push_constant) uniform objectBuffer { mat4 matrixObject; vec4 diffuse; } object; layout(set=0 , binding = 2 ) uniform MyBuffer { mat4 mW; …
  38. 38. 39 HOW DOES IT LOOK ? Buffers – copy data in a buffer • Create Buffer • Create staging buffer • Bind objects to some memory • Command buffer for copy • Enqueue command buffer • Note: could be put with other graphic commands for better efficiency
  39. 39. 40 Device Queue Command-buffer … Graphics pipeline Descriptor-Set Framebuffer Render-Pass Image Memory 2ndary Command-buffer … … Buffer Image View Buffer Sampler Image View Begin Render-Pass Bind Graphics-pipeline Bind Vertex/Idx Buffer(s) Bind Descriptor-Set(s) Draw… End Render-Pass Execute Commands Update Buffer Set misc. dynamic states Barrier synchronization Heap Cmd.Buffer Pool DescriptorSet Pool Command-buffer Image Image View Image View VULKAN COMPONENTS
  40. 40. 41 Device Queue Command-buffer … Graphics pipeline Descriptor-Set Framebuffer Render-Pass Image Memory 2ndary Command-buffer … … Buffer Image View Buffer Sampler Image View Begin Render-Pass Bind Graphics-pipeline Bind Vertex/Idx Buffer(s) Bind Descriptor-Set(s) Draw… End Render-Pass Execute Commands Update Buffer Set misc. dynamic states Barrier synchronization Heap Cmd.Buffer Pool DescriptorSet Pool Command-buffer IMAGES AND IMAGEVIEW Images represent all kind of ‘pixel-like’ arrays Textures: Color or Depth-Stencil Render targets : Color and Depth-Stencil Even Compute data Shader Load/Store (imgLoadStore) ImageView required to expose Images properly when specific format required For Shaders For Framebuffers
  41. 41. 42 HOW DOES IT LOOK ? Way more complex than OpenGL ! • Load image • Create an Image (1D/2D/3D/Cube…) • Create an Image-View • Aggregate layers/mipmap layers info (offsets, sizes) in a structure (VkBufferImageCopy) • Aggregate layers & mipmap data to contiguous memory • Create staging buffer + bind memory + copy data in it • Use command-buffer to copy to the image: layers and mipmaps • Layout transition of image for copy • vkCmdCopyBufferToImage • Layout transition of image for use by shader • Enqueue command buffer and execute Simple texture creation
  42. 42. 43 HOW DOES IT LOOK ? Simple texture creation
  43. 43. 44 Device Queue Command-buffer … Graphics pipeline Descriptor-Set Framebuffer Render-Pass Image Memory 2ndary Command-buffer … … Buffer Image View Buffer Sampler Image View Begin Render-Pass Bind Graphics-pipeline Bind Vertex/Idx Buffer(s) Bind Descriptor-Set(s) Draw… End Render-Pass Execute Commands Update Buffer Set misc. dynamic states Barrier synchronization Heap Cmd.Buffer Pool DescriptorSet Pool Command-buffer VULKAN COMPONENTS Descriptor-Set
  44. 44. 45 Device Queue Command-buffer … Graphics pipeline Descriptor-Set Framebuffer Render-Pass Image Memory 2ndary Command-buffer … … Buffer Image View Buffer Sampler Image View Begin Render-Pass Bind Graphics-pipeline Bind Vertex/Idx Buffer(s) Bind Descriptor-Set(s) Draw… End Render-Pass Execute Commands Update Buffer Set misc. dynamic states Barrier synchronization Heap Cmd.Buffer Pool DescriptorSet Pool Command-buffer DESCRIPTOR-SET Each DescriptorSet holds references to some resources Descriptor-Set-Layout defines how resources must be put together in a DescriptorSet Command buffers can then efficiently bind any or them They must match what shaders of each stage expect ! Descriptor-Set Image Memory Image View Buffer Sampler Heap DescriptorSet Pool Descriptor-set Layout GLSL Code layout(std140, set= 0 , binding= 0) uniform A { ... }; layout(std140, set= 0 , binding= 1) uniform B { … }; layout(std140, set= 1 , binding= 2) uniform C { … }; layout(set=0, binding=3) uniform sampler2D tex; … void main() { …
  45. 45. 46 Device Queue Command-buffer … Graphics pipeline Descriptor-Set Framebuffer Render-Pass Image Memory 2ndary Command-buffer … … Buffer Image View Buffer Sampler Image View Begin Render-Pass Bind Graphics-pipeline Bind Vertex/Idx Buffer(s) Bind Descriptor-Set(s) Draw… End Render-Pass Execute Commands Update Buffer Set misc. dynamic states Barrier synchronization Heap Cmd.Buffer Pool DescriptorSet Pool Command-buffer DESCRIPTOR-SET Descriptor-set Layout A Uniform Buffer for Vtx Storage Buffer for frag. Image View for frag Descriptor-set Layout C Uniform Buffer for Vtx Descriptor-set Layout B Image View for frag. Sampler for frag. shd Dset A1 Buffer L Image View M Buffer K Dset B1 Image View Q Sampler R Dset C3 Buffer S Command-buffer … Bind Graphics-pipeline Bind Descriptor-Set(s) Dset A2 Buffer O Image View P Buffer N ? Memory Heap Image M Buffer K Image P Image Q Buffer L Buffer N Buffer O Buffer S Buffer T Dset C2 Buffer T Dset C1 Buffer S ? Defined for Layout A+B+C
  46. 46. 47 HOW DOES IT LOOK ? Descriptor Set - initialization
  47. 47. 48 HOW DOES IT LOOK ? Descriptor Set – using it
  48. 48. 49 DESCRIPTOR SETS AND MULTI-THREADING Thread 1 Update Work Update resources in Desc. Sets Descriptor Pool Allocate Desc. Sets … more Vulkan work … Main thread Game Work Thread Coordination Swapping synchronize Descriptor Pool Allocate Desc. Sets Update resources in Desc. Sets … more Vulkan work … Thread 2 Update Work Update resources in Desc. Sets Descriptor Pool Allocate Desc. Sets … more Vulkan work … Thread 1 Update Work Update resources in Desc. Sets Descriptor Pool Allocate Desc. Sets … more Vulkan work … Thread 2 Update Work Update resources in Desc. Sets Descriptor Pool Allocate Desc. Sets … more Vulkan work … ! Descriptor Pool local to the thread ! cmd. Buffer Pool Create 2dary Cmd Buffer
  49. 49. 50 Device Queue Command-buffer … Graphics pipeline Descriptor-Set Framebuffer Render-Pass Image Memory 2ndary Command-buffer … … Buffer Image View Buffer Sampler Image View Begin Render-Pass Bind Graphics-pipeline Bind Vertex/Idx Buffer(s) Bind Descriptor-Set(s) Draw… End Render-Pass Execute Commands Update Buffer Set misc. dynamic states Barrier synchronization Heap Cmd.Buffer Pool DescriptorSet Pool Command-buffer Framebuffer Render-Pass VULKAN COMPONENTS
  50. 50. 51 Device Queue Command-buffer … Graphics pipeline Descriptor-Set Framebuffer Render-Pass Image Memory 2ndary Command-buffer … … Buffer Image View Buffer Sampler Image View Begin Render-Pass Bind Graphics-pipeline Bind Vertex/Idx Buffer(s) Bind Descriptor-Set(s) Draw… End Render-Pass Execute Commands Update Buffer Set misc. dynamic states Barrier synchronization Heap Cmd.Buffer Pool DescriptorSet Pool Command-buffer VULKAN COMPONENTS Framebuffer Render-Pass Image Image ViewImage ViewImage ViewImageView #0 ImageImageImage #0 Attachment Desc. • Image #0: fmt… • Image #1: fmt… • Image #2: fmt… • Image #3: fmt… Must match Sub-Pass #0 Desc. • Color: Image #0 • DST: Image #1 • MSAA resolve:Image #2 Sub-Pass #1 Desc. • Color0: Image #3 • Color1: Image #4 • DST: Image #1 • MSAA resolve:Image #5 • Framebuffer • Simpler than OpenGL • “Bag” or “Repository” of resource views • No role defined for the resources • Render-Pass • Really defines the role of Framebuffer resources • Can have more than 1 Sub-Pass • Each Sub-Passes defines which Framebuffer resource to use • invented for Tilers Arch Sub-Pass #N Desc. … Default Sub-Pass Can use many if compatibles
  51. 51. 52 HOW DOES IT LOOK ? Renderpass Creation (‘compacted’ notation for Vulkan structures)
  52. 52. 53 HOW DOES IT LOOK ? Framebuffer Creation and use
  53. 53. 54 Device Queue Command-buffer … Graphics pipeline Descriptor-Set Framebuffer Render-Pass Image Memory 2ndary Command-buffer … … Buffer Image View Buffer Sampler Image View Begin Render-Pass Bind Graphics-pipeline Bind Vertex/Idx Buffer(s) Bind Descriptor-Set(s) Draw… End Render-Pass Execute Commands Update Buffer Set misc. dynamic states Barrier synchronization Heap Cmd.Buffer Pool DescriptorSet Pool Command-buffer Memory (Vid) Heap 2 Memory (Sys) Heap 1 VULKAN COMPONENTS
  54. 54. 55 Device Queue Command-buffer … Graphics pipeline Descriptor-Set Framebuffer Render-Pass Image Memory 2ndary Command-buffer … … Buffer Image View Buffer Sampler Image View Begin Render-Pass Bind Graphics-pipeline Bind Vertex/Idx Buffer(s) Bind Descriptor-Set(s) Draw… End Render-Pass Execute Commands Update Buffer Set misc. dynamic states Barrier synchronization Heap Cmd.Buffer Pool DescriptorSet Pool Command-buffer MEMORY VULKAN OBJECTS Vulkan Objects referring to buffer(s) of data need binding to memory Vertex/Index Buffers; Uniform Buffers; Images/Textures… Vulkan Device exposes various Memory Heaps - Example: heap 0: size:12,288Mb (Video Memory of my K6000) heap 1: size:17,911Mb (System Memory of my PC) And various Memory Types from these Heaps. Example: Mem.Type Heap Flags 0 1 (sys.mem) - 1 0 (Video) DEVICE_LOCAL 2 1 (sys.mem) HOST_VISIBLE | HOST_COHERENT 3 1 (sys.mem) HOST_VISIBLE | HOST_COHERENT | HOST_CACHED Tegra: Adds one more: HOST_VISIBLE “NON-Coherent” Memory (Vid) Heap 2 Memory (Sys) Heap 1
  55. 55. 56 Device Queue Command-buffer … Graphics pipeline Descriptor-Set Framebuffer Render-Pass Image Memory 2ndary Command-buffer … … Buffer Image View Buffer Sampler Image View Begin Render-Pass Bind Graphics-pipeline Bind Vertex/Idx Buffer(s) Bind Descriptor-Set(s) Draw… End Render-Pass Execute Commands Update Buffer Set misc. dynamic states Barrier synchronization Heap Cmd.Buffer Pool DescriptorSet Pool Command-buffer MEMORY VULKAN OBJECTS Image (Tex) Image View Buffer (Uniforms) Image View Buffer (Vertices) Memory (Vid) Heap 2 Memory (Sys) Heap 1 matrices Vtx Buf. V1.xyzw V2.xyzw… Image (RT) rgba rgb Vtx Buf.
  56. 56. 57 RESOURCE MANAGEMENT Allocation and Sub allocation HEAP supporting A,B HEAP supporting B Allocation Type A Allocation Type B Image ... Cube Image Buffer Allocate memory type from heap Query Vulkan Object about size, alignment & type requirements Assign memory subregion to a resource (allows aliasing) BufferView BufferView Create resource views on subranges of a buffer or image (array slices...) Buffer
  57. 57. 58 RESOURCE MANAGEMENT #HappyGPU Memory Allocation Buffer UniformVertexIndex Memory Allocation Buffer Index Vertex Buffer Uniform Buffer Better... Buffer Index Vertex Buffer Uniform Buffer Not. So. Good. Bind same buffer with Offsets > 0 1 buffer can have many types of data
  58. 58. 59 HOW DOES IT LOOK ? Binding Memory to Objects – Simple use-case Mem properties previously gathered at init time
  59. 59. 60 SHADERS Vulkan uses SPIR-V passed directly to the driver Can be compiled from GLSL Via glslang or LunarG’s glslangValidator; Google ShaderC theoretically other languages could be compiled to Spir-V… Libraries available to compile GLSL to Spir-V from the application NVIDIA allows to compile GLSL directly glslangGLSL Some other language NVIDIA VK_NV_glsl_shader: Vulkan reads GLSL directly
  60. 60. 61 SHADERS Multiple entry points can be defined in a single Spir-V shader-module Prevents redundant code: shader module used by many Graphics-Pipelines Specialization Constants: early setup of constants for shaders in given Graphics-Pipeline Allows sharing snippets of code : easier to share common shader code Module vtx_main() frag_pastic(float t) Frag_metal()lighting() rotate(…) Graphics pipeline A Vtx_main() frag_pastic(1.1) Graphics pipeline B Vtx_main() frag_metal() Graphics pipeline C Vtx_main() frag_wood() frag_wood() Graphics pipeline A Vtx_main() frag_pastic(3.2)
  61. 61. 62 VULKAN WINDOW SYSTEM INTEGRATION (WSI) WSI manages the ownership of images via a swap chain One image is presented while the other is rendered to WSI is a Vulkan Extension WSIDisplay Swap Chain (images) Application Submit image to WSI The display owns the image Acquire image from WSI The application owns the image
  62. 62. 63 NVIDIA OPENGL VULKAN INTEROP Alternative to WSI: GL_NV_draw_vulkan_image Create an OpenGL Context and all the usual things Create Vulkan Device Rendering Loop involves both OpenGL and Vulkan Blit the Vulkan image to OpenGL backbuffer: glDrawVkImageNV Extra care on synchronization (Semaphores) Bonus: Mix OpenGL rendering (UI overlay…) with Vulkan Allows smooth transition in projects OpenGL Vulkan
  63. 63. 64 HOW DOES IT LOOK ? GL_NV_draw_vulkan_image Initialize…
  64. 64. 65 HOW DOES IT LOOK ? GL_NV_draw_vulkan_image Submit commands to Queue with semaphores Backbuffer Blit
  65. 65. 66 PRE-REQUISITES TO WORK WITH VULKAN Lunar-G (http://lunarg.com/ ) Vulkan Loader (+Source code) Tools: Spir-V compiler for GLSL code and other libraries Layers: intermediate code invoked by Vulkan API functions to help debug Vulkan Includes Drivers: GeForce Experience https://developer.nvidia.com/vulkan-driver NVIDIA resources: https://developer.nvidia.com/Vulkan
  66. 66. 67 RECAP’ ON NVIDIA-SPECIFIC FEATURES Compatible GPUs for Vulkan: Kepler and Higher; Shield Tablet; Shield Android TV VK_NV_glsl_shader : GLSL can be directly sent to Vulkan VK_NV_dedicated_allocation : more efficient memory usage GL_NV_draw_vulkan_image can replace WSI 16 Queues. All available for all kind of use; 1 Queue for Copy-Engine only 3 frames (max) in flight with WSI All Host memories are “Coherent” (except one for Tegra) Layout transitions don’t exist in our HW (VK_IMAGE_LAYOUT_GENERAL) Linear-Tiling only for 2D non-mipmapped textures… please avoid (bad performance) Shaders never need re-compilation due to states in Graphics-pipeline
  67. 67. 68 NSIGHT FOR VULKAN
  68. 68. 69 RECAP’ ON VULKAN PHILOSOPHY Validate as much as possible up-front (DescriptorSets; Pipelines…) The driver doesn’t waste time on figuring-out how to set things-up Reuse existing patterns of Graphics-Pipelines: cached pipelines Know your application: Taylor Vulkan design according to it Know your memory usage: You are in charge of optimal sub-allocations Explicit multi-threading for graphics: Application’s responsibility Explicit Resource updates: Either through [non]Coherent buffers; or Queue-Based DMA transfers
  69. 69. 70 FEW WORDS ON VKCPP PROJECT C++11 to the rescue • Open-Source Project of a C++11 overlay for Vulkan: became Khronos-offcial (!) • Simplify Vulkan usage by • reducing risk of errors, i.e. type safety, automatic initialization of sType, … • Reduce #lines of written code, i.e. constructors, initalizer lists for arrays, … • Add utility functions for common tasks (suballocators, resource tracking, …) http://on-demand.gputechconf.com/gtc/2016/events/vulkanday/Vulkan_C++.pdf https://developer.nvidia.com/open-source-vulkan-c-api https://www.khronos.org/news/permalink/khronos-introduces-vulkan-hpp-open- source-vulkan-c-api
  70. 70. 71 VKCPP PROJECT Two C++ based layers Autogenerated ‚low-level‘ layer using vulkan.xml • Type safety • Syntactic sugar • Lightweight layer; Keeps you closer to the real Vulkan Hand-coded ‚high level‘ layer • Reduce code complexity • Exception safety, resource lifetime tracking, … • Closer dependency with VkCpp internal implementations
  71. 71. 72 NATIVE VULKAN VS. VKCPP CODE Native Vulkan: ~750 lines vkCPP: ~200 lines
  72. 72. 73 REFERENCES Vulkan info from NVIDIA: https://developer.nvidia.com/Vulkan https://developer.nvidia.com/vulkan-graphics-api-here Samples + Source code in OpenGL and Vulkan: https://github.com/nvpro-samples Other: https://gameworks.nvidia.com https://developer.nvidia.com/designworks http://vulkan.gpuinfo.org/listreports.php https://developer.nvidia.com/open-source-vulkan-c-api
  73. 73. THANK YOU HTTPS://DEVELOPER.NVIDIA.COM/DESIGNWORKS TLORACH@NVIDIA.COM

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