you can use 3d graphics to enhance and differentiate your metro style app

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3D Graphics in Metro Style Apps and Games

Chas BoydPrincipal Program ManagerMicrosoft Corporation

PLAT-751T


You can use 3D graphics to enhance and

differentiate your Metro style app.


Globe

A 3D foundation for geotagging, map mash-ups, etc.

demo


3D app scenarios

• Map mashups• Visualization• Data-mining• Medical• Scientific

• Games


Agenda

• A lap around Direct3D -object model• New features of Direct3D11• Supporting the whole range of PCs

• Resources available for Direct3D developers

Takeaways• You will understand how to get started writing a

3D Metro style app


DirectX 11.1

• DirectX11.1 is the version of DirectX11 that ships in Windows 8

• It has some minor new features added, but most of the improvements are behind the scenes in terms of integration with the other core OS components


Architecture

DXGI

VideoDirect3DDirectCompute

Direct2DC++ AMPMedia

Foundation

HTML, XAML

Direct3D object model

VertexDecl

VertexShader

PixelShader

OutputMergerState

Direct3D object model

GraphicsMemoryResource

s

Graphics

State

Interface

Mesh Object

TextureObject RenderTarget

Objects

Direct3D Device


The Direct3D device object

• Primary Direct3D API object• Represents the core rendering engine

• Properties of the device == state of graphics chip

• All rendering resources are bound to the context• Context abstraction enables multi-threading

Direct3D Device Context

Vertex Processo

r

Triangle Rasterize

r

Pixel Processo

r

Output Merger

Vertex Processo

r


Mesh object

• Meshes are stored in vertex buffers• Indexed with index buffers

• Vertex buffers enable mesh data to be cached in graphics memory

• Vertex declaration defines a the data formats for the hardware

Vertex BufferIndex

Buffer

Vertex DeclVertex Format

Texture object

Base Image

Shader Resource View

MIP Chain

Pixel Format

Texture Data

RenderTarget object

Swap Chain

=BackBuffer

+ FrontBuffe

r

Render Target View Pixel Format

Pixel Data

Creating a swap chainWindows::UI::Core::CoreWindow^ coreWindow; // app’s core windowMicrosoft::WRL::ComPtr<ID3D11Device1> d3dDevice; // rendererMicrosoft::WRL::ComPtr<IDXGISwapChain1> dxgiSwapChain; // front/back buffers of RT

// Obtain the final swap chain for this window from the DXGI factory.dxgiFactory->CreateSwapChainForImmersiveWindow( d3dDevice.Get(), // the Direct3D device that will render to it DX::GetIUnknown(coreWindow), // IUnknown interface on our core window &swapChainDesc, // double or triple buffered, stereo, etc. nullptr, // allow on all displays &dxgiSwapChain // the resulting swap chain object );

Depth stencil object

Depth/Stencil View

Depth Buffer

Pixel Format

Pixel Data


HLSL shaders

float4 SimplePixelShader( sPSInput input ) : SV_TARGET { float3 toLight = normalize( float3(1,1,0) ); float intensity = saturate( dot( input.norm, toLight ) ); return SimpleTexture.Sample( SimpleSampler, input.tex )*intensity; }

VertexDecl

VertexShader

PixelShader

OutputMergerState

Direct3D DeviceContext


Compiling a shader

• HLSL is compiled off-line with fxc.exe• This enables 90% of the work to happen up front

• Driver translates (JITs) to it’s own instruction set at load time

• On call to d3dDevice->CreatePixelShader()• Enables operation across hardware vendors and

generations


Direct3D supports a large hardware base

• Hardware is organized into a sequence of feature levels• From Feature_Level_9_1 to Feature_Level_11_1

• Many algorithms can use the same code across levels• Others may need separate codepaths for optimal

performance

• See Talk <752> Tuning GPU Usage for Any Form Factor

New Features of Direct3D11.1


Direct3D capabilities

Advanced features

• Tessellation• DirectCompute• Double precision• HQ texture compression

Power-oriented features

• Low-precision HLSL instructions

• Optimizations for tiling GPUs


Tessellation

• Available on DX11 feature level hardware• Enhances mesh quality and detail• Render using base mesh on slower PCs

• Use subdivided mesh on faster ones


DirectCompute

• Delivers general-purpose GPU processing to Metro style apps• Teraflops of performance

• Foundation of C++ AMP (Accelerated Massive Parallelism)

• Runs on same device object as Direct3D• So sharing resources for rendering is instantaneous


New shader instructions

• Technical computing needs fast double precision math

• New instructions were added for key transcendentals• Full performance on newer GPUs• Emulated on older ones

• HLSL now supports an image search instruction• msad4: Vector Sum of Absolute Differences• Accelerated in future hardware, emulated on Windows 8

drivers


Texture compression

• Direct3D supports texture compression• BC1 4-bits/pixel for RGB formats 6x compression ratio• BC2,3 8-bits/pixel for RGBA formats 4x compression ratio

• This is strongly recommended• Smaller package means faster downloads of your app

• Feature Level 11 hardware added 2 new formats• BC6 for high dynamic range imagery• BC7 for higher quality content


Texture compression example

8k x 4k image @ 24 bits/pixel = 32MPix

WorldMap.bmp 98MB 1x

WorldMap.dds (BC1) + mip maps 22MB 5x

WorldMap.zip (e.g. in .appx package) 7MB 14x

WorldMap.jpg 5.5MB 17x


Texture compression quality

.Worldmap.jpg

Worldmap.dds BC1 compressed


Power optimizations: precision

• Optimizing for power and battery life is important

• All shaders in DirectX currently default to 32-bit precision

• As of Windows 8, you can use 16-bit float or int data• Enables some hardware to work at twice the rate for the

same power


Optimizations: tiled renderers

• Some power-optimized GPUs use an output image cache called a tile

• These chips can get a performance boost with a special flag

m_swapChain->Present(1, 0); // present the image on the display

ComPtr<ID3D11View> view; m_renderTargetView.As(&view) // get the view on the RT

m_d3dContext->DiscardView(view.Get()); // release the view

Developer resources


Visual Studio 11


Asset compilation

• Goal: optimize 3D assets as part of build phase• Runtime app package contains only optimized data

• Keep the package download as small as possible• Don’t keep users waiting for your app!


Shader.cso

Asset compilation

Shader.hlsl

Author-time Asset

Build Step Run-time Asset

myApp.app

x

Packager

Package

Texture.bmp

Mesh.obj

Music.wav

Texture.dds

Mesh.vbo

Music.wma

fxc.exe

dxtex

obj2vbo

myTool


New samples for Metro style apps

• The samples are designed to• Make it easy to see the API calls used and how they work• Show incremental steps toward building a real app

• Samples tip: set a breakpoint in DirectXSample.h #line 18• to see HRESULTS before the exception


Spectrum of sample types

• Tutorials• Introduce very basic initial concepts from step 1• In-line code to favor readability over factoring of

functionality• Simple samples• Provide starting points for developers adding specific

techniques• Each sample builds on the last demonstrating another

technique• SimpleD3D, Simple3DTouch, ResourceLoading, D3DPostProcessing,

Stereo…

• E2E sample ‘starter kits’ with source• Demonstrate integration of all components (basic*.cpp)• Simple3DGame, ModernMarbleMaze


Hands-on Labs

• <764> Direct3D Tutorial• Basic elements of 3D graphics taught step-by-step using

Direct3D

• <709> Visual Studio 11 Visualization and Debugging• DirectX-oriented features like texture viewing, shader

analysis, mesh validation, API call debugging

• <763> Visual Studio Debugging• More chances to try out the debugging and 3D basics


Related sessions

• [PLAT-766T] Introduction to DirectX for Metro style apps

• [PLAT-750T] Build your first Metro style game

• [PLAT-752T] Tuning GPU usage for any form factor

• [TOOL-761T] A lap around DirectX game development tools

• [PLAT-756T] Building Xbox LIVE games for Windows 8


Windows 8 is the ideal platform for 3D apps.


Use 3D in Metro style apps

• 3D is a valuable way to differentiate your Metro style app

• Direct3D11 is the solution for 3D in Windows 8

• Direct3D is fully supported with APIs, tools, and samples

• Go build your 3D Metro style app!


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© 2011 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to

be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

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