Direct3D Tools

1
Direct3D Tools

• Chas. Boyd
• WGGT
• Microsoft Corporation

2
Outline

• D3DX Utilities
• Mesh, Math, Image routines
• Shader routines
• Effect Framework
• Fallback/LOD system
• Cross tool material
• Fragment linking
• What is it?
• How to use it?

3
Math

• Set of commonly used math functions
• Vector math
• Matrix transforms
• Performance optimized for Intel and AMD special
  instruction sets

4
Image

• Core operations
• Format conversion and i/o
• For jpg, png, tga, bmp, ppm, dds
• Compression dxtc
• Scaling, Mip-Map generation
• CubeMap, VolumeMap i/o
• Procedural texture loaders
• Now supports gamma correction!

5
Mesh

• Current Routines
• Progressive mesh LOD tuner
• Mesh cleaner
• Ray intersection
• Skinning support
• Mesh optimizer
• Normal, tangent basis generator
• New Routines
• Patches
• Frame Hierarchy
• Animation System

6
D3DX Skinning

• Setup data for hardware skinning
• Non-indexed skinning (DirectX 7 style)
• Indexed palette skinning (DirectX 8, VS)
• Full software skinning
• If doing on skinning on CPU
• More efficient than emulating HW
• Needs only a VB
• Works with Patches, PMesh and Meshes
• Convert data between various skinning algorithms

7
D3DX Patch Tessellation API

• Software tessellation for High Order Primitives
• Full match of DirectX 9 hardware
• N-Patches, Bezier, B-Splines, Catmull-Rom
• Fractional tessellation
• Adaptive tessellation
• Displacement mapping

8
D3DX Displacement Mapping

• Use tessellated vertex texture coordinate to
  sample a 2D texture
• Sampled value is a per vertex displacement value
• Sampled data can be 1-4D
• Actual displacement done in vertex shader
• Adaptive tessellation supports MIP-mapped
  sampling
• MIP level based on tessellation factor

9
Shader Management

• Modern apps must manage a combinatoric number of
  shaders
• Due to varying effects desired
• Diffuse, ambient, or specular terms
• Skinning on/off, number of lights
• Due to different hardware generations
• DirectX 8, 9, 9.1
• FF pipeline does not have these issues

10
Solution Effects

• D3DX Effect Framework
• Routines to load and select shaders
• Originally developed to manage multitexture
  shaders in DirectX 6
• Now fully integrated with the HLSL

11
Effect Framework

• Encapsulation of device state
• Enables scalable rendering techniques
• Allows controlled fallback
• Cant just switch to multi-pass
• Older hardware cant do more passes since fill
  rate is less
• Helps rapid prototyping
• Runtime interpretation of text-based effect
  definition

12
Effect Framework Goals

• Standard way of representing shading algorithms
• Ease of authoring
• Enable some abstraction between author of effect
  and user of the effect
• Facilitates sharing of effects
• Enables effect geometry optimizations to be
  done at author-time, install-time, load-time or
  runtime
• Cross Platform
• Efficient for runtime use

13
Effect Model
Effect Water
Technique DX9
pass0
pass1
Technique DX8
pass0
Technique DX7
pass0
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Effect FrameworkFallback Techniques

• Techniques are grouped by their quality or LOD
• Techniques can be chosen based on what hardware
  creates successfully
• Can test performance in back buffer
• User responsible for drawing geometry

15
Sharing values across effects

• Shared parameters (aka Globals)
• Shared across multiple effects
• Tagged in effect file as shared
• User selects the list of effects whose shared
  parameters are linked at runtime
• Setting once updates all linked effects

16
Annotations

• Name/Value pairs attached to variables
• App specific information about the variable
• Can be from a set of defined annotations
• Used to allow effect files to be shared between
  tools
• i.e. the Name value is interpreted as the
  resource name for textures, vertex shaders, etc.
• Work with Techniques and Passes as well
• Can be used to specify additional information on
  how the pass/technique works.
• i.e. the pass needs to be rendered to a texture

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Annotation syntax
Texture DiffuseTex lt string Name
tiger.bmp int Width 256 int Height
512 gt

• Name/Value pairs
• Information for application only
• Provided to application through interface
• Not used by effect framework

18
Design for Runtime Efficiency

• Compile effects into hardware friendly format
• State blocks/constant arrays
• Efficient setting of effect parameters
• Can set parameters within effect application
• Integration with an optimizing language back end
• Caching common parameter combinations

19
Unify Fixed and Programmable Pipelines

• A consistent framework for programming shaders
• Fixed-function programming using render states,
  texture stage state, fixed-function vertex
  processing
• Assembly level vertex and pixel shader
  programming
• Shading language based programming

20
Unify Cross-Platform Programming

• Techniques in an effect can span shader models
  (like VS 1.1, VS 2.0, etc.)
• Unified parser allows handling the same effect
  file cross platform
• Only techniques that validate on runtime platform
  available for actual use

21
Effect-Language Integration

• Techniques can call language functions
• This is where the back-end is specified
• Same function can be used in multiple techniques
  compiled to multiple back-ends
• Expressions of parameters can be used in state
  assignment
• Per-primitive expressions detected and optimized
  out by compiler when within an effect

22
Effect and HLSL Usage

• Language functions can be compiled as either
  pixel or vertex programs
• Do not have to specify vertex constants
• Constant table from shader will be matched up
  with the corresponding effect variables
• Pixel shader samplers
• Matched up just like any other variable
• The difference is that a block of state is
  applied to the stage that the sampler is bound to.

23
Specialization

• Specify constants that are to be literals
• via ID3DXEffectCompiler Interface
• Call CompileEffect() method
• returns pre-optimized shader
• Easily generate multiple shaders optimized for
  specific cases
• Can helps shader management by generating them on
  the fly

24
Materials

• Effects are a good way to define materials
• Contain state required for drawing
• Contain Annotations with app info
• Texture filenames
• What type of geometry is required
• What type of skinning
• Tangents/Binormal requirements
• App specific information on how to draw
• i.e. lighting format info, render to texture
  info, etc.
• Convenient parameterization
• Allows for materials with user customization

25
Parameterized Effects

• Effects can have parameters of various types
• Parameters augment static state description in
  the .fx files
• How (and which) parameters get used defined by
  the effect
• Allows for a convenient material system

26
Example Material
texture tJerseyTexture lt string Name
jersey.bmp gt float4 JerseyColor 1.0, 0.0,
0.0, 1.0 technique UniformUnskinned lt string
TransformType Unskinned gt pass
VertexShader compile vs_1_1
DrawPlayer(JerseyColor) Texture0
(tJerseyTexture) technique
UniformSkinned lt string TransformType
NonIndexedSkinned gt pass
VertexShader compile vs_1_1 DrawPlayerSK(JerseyC
olor) Texture0 (tJerseyTexture)

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Effect Instance

• An effect instance is the information required to
  instantiate a specific material
• Contains
• Name of the effect
• A list of Name/Value pairs
• Each name represents an effect param
• The value is the initial value for that effect
  parameter

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Why use Effect Instances?

• Allows one effect file to be customized for use
  as a number of materials
• i.e. draw multiple different types of leather
  with one vertex/pixel shader combination
• Each material instance could specify
• Color of leather
• Texture for the grain of the leather
• Other leather parameters
• Higher level abstraction of materials
• Convenient for models to reference
• Allows for customization specific to model
• While still allowing for sharing of code and
  initial values

29
Effect Instance Example

• Football Jersey example
• EffectInstance A
• Jersey.fx
• tJerseyTexture_at_Name hawks.bmp
• JerseyColor 1.0, 1.0, 1.0, 1.0
• EffectInstance B
• Jersey.fx
• tJerseyTexture_at_Name generic.bmp
• JerseyColor 0.0, 1.0, .0., 1.0

30
Linking Effects with Geometry

• .X file extensions to link effect with geometry
• Uses effect instances
• Effect filename
• Initial values for effect parameters
• D3DX API support for associating effects with
  meshes
• D3DXEFFECTINSTANCE
• Structure used by D3DX to represent effect
  instances
• Simple struct containing
• Effect filename
• Array of Name/Value pairs

31
Effect Performance Tip

• Handles vs Parameter Names
• Handle usage avoids string lookups
• All methods that take names accept both handles
  and strings
• Strings are great for prototypes and tools, but
  not fast enough for heavy duty use
• Easy to get a handle for any name
• IsParameterUsed
• Easy way to tell if a value is used by the
  current technique
• Perf advantage if only used values are updated

32
Shader Management

• Dealing with the permutation problem

33
How to generate groups of similar shaders?

• Use HLSL with compile time constants
• Compile the shader N times with different
  constants
• Great if permutation set is know ahead of time
• Run-time compilation is possible, although
  expensive
• Works with standalone HLSL code and Effect files
• Link shader fragments
• Cheap run-time linking
• Generate shaders needed only if necessary
• Downside is the lack of fragment to fragment
  compile time checks

34
Fragment Linker

• Efficiently links together
• HLL fragments
• And asm fragments
• Current Features
• Symbol table resolution
• Register use optimization
• Dead code removal
• via ID3DXFragmentLinker interface

35
ASM Fragment Syntax

• Similar syntax to asm blocks in effect files
• Use logical names for registers
• Prefix of name specifies register type
• r_ for temp registers
• v_ for input registers
• c_ for constant registers
• Declared like a variable to link fragment name
  and asm block

36
ASM Fragment Syntax (2)

• Constant registers (c_)
• Constants must be defined at global scope
• Provides type information for building constant
  table
• Input registers (v_)
• Name portion is the semantic
• The semantic is used to build dcl statements
• Temp registers (r_)
• User defined register names
• Data links between fragments
• Reads of r_ will get the last value written to
  that name
• Writes of r_ will specify the value for the next
  reader

37
ASM Fragment Sample
vertexfragment ComputeGlowAsm asm_fragment
vs_1_1 // normalize normal dp3
r_Length.w, r_TransformedNormal.xyz,
r_TransformedNormal.xyz rsq r_Length.w,
r_Length.w mul r_TransformedNormal.xyz,
r_TransformedNormal.xyz, r_Length.www mov
r_Temp.x, c_One.x mad r_Power.z,
r_TransformedNormal.z, -r_TransformedNormal.z,

c_One.x mul r_Power.z, r_Power.z,
r_Power.z mul oD0, c_vGlowColor, r_Power.z
mad r_TransformedPosition.xyz,
r_TransformedNormal.xyz,
c_vDisplace.xxx, r_TransformedPosition.xyz
mov r_TransformedPosition.w, c_One.x m4x4
oPos, r_TransformedPosition, c_mProjection

38
HLSL Fragment Syntax

• Follows all standard rules for defining a HLSL
  function
• The only addition is the user defined r_
  semantics
• In the input/output list, it is possible to
  define a user semantic beginning with r_ anywhere
  a profile semantic is valid.
• The r_ semantics are the links that are setup
  between the shader fragments
• HLSL fragments have to be declared
• VertexFragment F compile_fragment vs_1_1
  Func()

39
HLSL Fragment Sample
void TransformUnskinned( float4 vPos
POSITION,
float3 vNormal NORMAL, out float3
vTransformedPosition r_TransformedPosition,
out float3 vTransformedNormal
r_TransformedNormal ) // Transform the
position into view space vTransformedPosition
mul(vPos, mWorldView) // Tranform the
normal into view space // (just use the upper
3x3 of WorldView) vTransformedNormal
mul(vNormal, (float3x3)mWorldView)
vertexfragment Transform compile_fragment
vs_1_1 TransformUnskinned()
40
HLSL Fragment Sample
void ComputeGlow( float3 vTransformedPositio
n r_TransformedPosition, float3
vTransformedNormal r_TransformedNormal,
out float4 Position POSITION, out float4
Diffuse COLOR) vTransformedPosition
vTransformedNormal vDisplace.x //
determine the strength of the glow by the normal
direction float fPower vTransformedNormal.z
-vTransformedNormal.z1.0f fPower
fPower // tranform position into screen
space from view space Position
mul(float4(vTransformedPosition, 1.0),
mProjection) // output color is the
compute power times the glow color Diffuse
vGlowColor fPower vertexfragment
ComputeGlowHLSL compile_fragment vs_1_1
ComputeGlow()
41
Assembling Fragments

• D3DXAssembleFragments
• Loads all fragments declared in source file
• If a fragment is ASM it is assembled
• If a fragment is HLSL it is compiled
• Most compile errors occur here
• Missing linked registers are found later
• Standard list of sources
• Memory, Resource, File, etc.
• Same include system as Assembler and Compiler

42
ID3DXFragmentLinker

• AddFragments
• Adds fragments built from file by
  D3DXAssembleFragments
• LinkShader
• Generates binary of shader from list of fragments
• LinkVertexShader
• Generates shader object from a list of fragments
• Has a cache of recently generated fragments

43
How to use a linked shader

• Has a Constant Table
• Can be treated like any normal HLSL generated
  shader
• Has dcl statements
• Links up to vertex data with the correct dcl
  statements
• Use a linked shader just as you would any other
  HLSL shader
• ASM fragments vs HLSL fragments make no
  difference
• Constant table and input dcls are always present

44
Summary

• D3DX Effects
• Simplifies usage of shaders
• Convenient as materials
• Fragment Linking
• Allows for building up of shaders
• Provides run-time compilation without the perf
  hit of a full compile
• Both effects and fragments work great with HLSL

45
Shaders

• Shaders are the next step in graphics
  API/hardware evolution
• Need to use abstractions to help solve the
  problems with the number of shaders required

46
Four LibrariesWhich do I use?

• D3dx.lib
• This is the version to use with your shipping
  product
• D3dxdt.lib
• Static debug version for use in debugging only
• D3dxd.lib
• Imports for the dynamic debug version of the
  library
• D3dxd.dll

47
Action Items

• Sign up for the DirectX 9 Beta
• URL http//www.betaplace.com
• User ID DirectX9
• Password DXBeta
• Check it out!
• Use it in your research development
• Let us know what you think
• directx_at_microsoft.com

48
Questions
49
Exporters

• What is available?
• Discreet 3ds Max
• 3.x, 4.x
• AliasWavefront Maya
• 2.5, 3.0, 4.0
• NewTek Lightwave 3D

50
Exporters

• What can be exported
• Objects
• Polygonal
• Materials
• Basic now
• Animation
• Matrix
• Skinning

51
Exporters

• What will be exported
• Objects
• Patch support
• Materials
• Effect file linking
• Shader matching
• Animation
• Advanced skinning

52
D3DX Frame Hierarchy

• Struct D3DXMESHCONTAINER
• Struct D3DXFRAME
• All members public
• Can be extended with app specific members
• Utility functions that work on hierarchies of
  these structs
• Designed to work with derived structs

53
Struct D3DXMESHCONTAINER
typedef struct _D3DXMESHCONTAINER LPTSTR
Name union LPD3DXMESH
pMesh LPD3DXPATCHMESH pPatchMesh LPD3DXPME
SH pPMesh LPD3DXMATERIAL
pMaterials LPD3DXEFFECTINSTANCE
pEffects DWORD
NumMaterials DWORD
pAdjacency LPD3DXSKININFO
pSkinInfo _D3DXMESHCONTAINER
pNextMeshContainer D3DXMESHCONTAINER,
LPD3DXMESHCONTAINER
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Struct D3DXFRAME
typedef struct _D3DXFRAME LPTSTR Name
D3DXMATRIX TransformationMatrix
LPD3DXMESHCONTAINER pMeshContainer struct
_D3DXFRAME pFrameSibling struct _D3DXFRAME
pFrameFirstChild D3DXFRAME, LPD3DXFRAME
55
Frame Hierarchy Functions

• Load / Save to .X files
• Append/delete nodes
• Compute bounding sphere
• Integrate with animation interface
• And more

56
D3DX Animation API

• Key frame interpolation
• Linear, spline, quaternion, etc
• Animation blending (n-way)
• For mixing animations
• Smooth transitions
• Independent of frame hierarchy
• Just point to data being animated

57
Animation Terminology

• Interpolator
• Animation sets
• Set of interpolators
• Tracks
• Subset of animation sets that are currently being
  blended
• Target Matrices
• Specified by app
• Results of blended interpolation go here

58
Animation Tracks

• Has an associated animation set
• Blending weight
• Time transform
• Scale and offset
• Convert from animation set units to global units
• Used to control animation speed
• Enable / Disable

59
Animation Transitions

• Track properties can themselves be changed over
  time
• Linearly so far
• Change track weight over time
• Change track speed over time
• Modify enable / disable status over time