Ritual ™ Entertainment: Next-Gen Effects on Direct3D ® 10 Sam Z. Glassenberg Program Manager Microsoft ® – Direct3D ® Doug Service Director of Technology Development Ritual™ Entertainment

Overview  Crash Course in Direct3D 10  …What’s a Geometry Shader?  Ritual: Targeting Direct3D 10

Direct3D 10: Design Imperatives  Consistency (like a console)  Guaranteed base feature set for you to target no ‘caps’  Strictly-defined behavior across all chipsets  Performance  Dramatically improved small-batch performance by design  Offload the CPU with a more powerful geometry engine  Visual Effects  Increased flexibility and programmability  New hardware capabilities

Overview: The New Hardware Pipeline  Texture Arrays  Geometry Shader  Stream Output  Resource Views  Input Assembler  Common Shader Core (SM 4.0)  Integer/Bitwise Instructions  Comparison Filtering  Constant Buffers  State Objects  New compressed formats for HDR, normal/bump map content  More textures, RT’s, instructions, registers, interstage communication  Predicated Rendering  Alpha-to-Coverage  Multisample Readback  …

Overview: The New Software Stack  Streamlined and Layered Runtime  Clean and Consistent API  Robust debugging layers  Lean’n’mean core  New HLSL Compiler w/ New Language Features  New Effects System  Built upon the new Windows Vista ™ Display Driver Model

New Resource Types Texture1D/2D Array  Dynamically Indexable in the Shader

New Resource Types Texture1D/2D Array  Dynamically Indexable in the Shader  Bind-able as Render Targets  Each RenderTarget/DepthStencil can be a Render Target Array

Ubiquity of Resource Access Resource Views Example: Cubemap  Views enable interpretation of resources at different bind locations

Ubiquity of Resource Access Resource Views Example: Cubemap

 Views enable format re-interpretation of resource data Ubiquity of Resource Access Resource Views Example: Cubemap

Resource Views: Applications  Depth/Stencil Readback  Render-To-Cubemap  Render-To-Volume  Render-To-Buffer  Render-To-Bitfield  Render-To-Mipslice  Custom Data Packing/Unpacking  LOD Clamping

The Old Pipeline Direct3D 9 and Direct3D 9-based Platforms  One Vertex In  One Vertex Out

The Old Pipeline Direct3D 9 and Direct3D 9-based Platforms

The New Pipeline Direct3D10 – Geometry Shader  Access to the whole primitive  Triangle  Line  Point  With adjacency

The New Pipeline Direct3D10 – Geometry Shader Usages  All-GPU Material Systems  Per-Primitive material selection & setup  Compute edge lengths and wrinkle models  Compute plane equations  Compute silhouette edges  Set up barycentrics to exceed # of interpolators

Geometry Shader Amplification and De-Amplification  Emits primitives of a specified output type (point, linestrip, trianglestrip)  Limited geometry amplification/de- amplification: Output values per invocation  No more 1 in / 1 out limit!  Shadow Volumes/Fur/Fins  Procedural Geometry/Detailing  All-GPU Particle Systems  Point Sprites

Geometry Shader Amplification and De-Amplification  Emits primitives of a specified output type (point, linestrip, trianglestrip)  Limited geometry amplification/de- amplification: Output values per invocation  No more 1 in / 1 out limit!  Shadow Volumes/Fur/Fins  Procedural Geometry/Detailing  All-GPU Particle Systems  Point Sprites

Geometry Shader System-Interpreted Values  GS Can Emit a System-Interpreted Value: RenderTargetArrayIndex for the primitive  Choose a slice for render-to-volume  Choose a face for render-to-cubemap  MRT still specified in the PS RenderTargetArrayIndex = 0

Geometry Shader System-Interpreted Values  GS Can Emit a System-Interpreted Value: RenderTargetArrayIndex for the primitive  Choose a slice for render-to-volume  Choose a face for render-to-cubemap  MRT still specified in the PS RenderTargetArrayIndex = 2

Stream Output  Streams VS/GS results to one or more buffers in memory  DrawAuto() to draw dynamic amounts of GS data without App/CPU intervention  Uses:  Iterative/procedural geometry processing  All-GPU particle systems …… DrawAuto()