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Strategies and Techniques Strategies and Techniques for for
Real-Time ShadersReal-Time Shaders
Neil HazzardNeil Hazzard
Software EngineerSoftware Engineer
Autodesk, Media and Autodesk, Media and EntertainmentEntertainment
Overview
Recap from GDC 2005 What’s new in 3ds max 8 Scene Effects Extending effects with MAXscript Tips Lots of Demos…
Quick Recap from GDC 2005 3ds max supports HLSL Effect files Dynamic UI creation based on Semantic and
Annotations in the file Automatic update of changed file and
bitmaps Based on Parser Technology
Two Formats supported. 3ds max and DxSAS 0.8 MAXScript extendible GDC 2005 session available
http://sparks.autodesk.com/downloads
What’s new in 3ds max 8
New Annotation “ColorChannel” specifies whether a Map Channel contains color information. int texcoord1 : Texcoord < int Texcoord = 1; int MapChannel = 10; bool ColorChannel = true; >;
#define support - _3DSMAX_, 3DSMAX, MAX & _MAX_
Easier support for max specific code, by using #ifdef _MAX_ Use of DiffuseMap semantic to provide better
Material Editor sample slot rendering Scene Effects
Scene Effects Effects that work at the scene level
Pre Effects – runs before any geometry is drawn
Useful for background images Post Effects – runs after all geometry is
drawn Any “post production” work – blur, glow etc..
Environment Effects – special type that process the scene for use in per object rendering
Ideal for Shadow Maps or CubeMaps generation
Only work with the DirectX 9 Shader Material
Using Scene Effects - 1/4
Scene effects use a ParamID of 0x003 Tells the system to use the correct parser Uses bool PreShader = true; to help the parser
with usage. Post effects receive the render target
containing the scene in a texture parameter called SceneMap.
Pre Effects simply render into the current active render target.
Load the scene effects using the Scene Effect Loader Utility
Using Scene Effects - 2/4 Example of the post_output.fx file
#include "quad.fxh“ //helper file for drawing quadsstring ParamID = "0x003"; //tells the system what parser
//Macro to define the Scene texture and samplerDECLARE_QUAD_TEX(SceneMap,SceneSampler,"X8R8G8B8")
//Simple pixel shader that simply outputs the input scene datafloat4 OutputPS(VertexOutput IN) : COLOR{
float4 texCol = float4(tex2D(SceneSampler, IN.UV).xyz,1);// Do anything else herereturn texCol;
}
Using Scene Effects - 3/4
Environment Effects Run before the main scene output starts Should run in conjunction with object
based shaders Object shaders can then use specific
transforms setup by the environment stage An Example is light transforms for Shadow maps
Use multiple techniques, one for environment pass and another for final pass. Have a naming convention so the parser can set them dynamically
Can create maps that would be used by objects based effects
Using Scene Effects – 4/4
Developers can write their own scene parsers
Node sorting and filtering can be implemented The utility simply sorts based on the
GBuffer ID and filters non DirectX 9 Shader materials
New interfaces – see RTMax.h IDxSceneManager, IValidateNodeCallback
and IDxSceneTransformManager
Extending with MAXScript
Scripted Material
Auto Generated UI
Extending with MAXScript
Scripted Material plugin material StandardFX
name:"StandardFX"classID:#(692421,413582)extends:DirectX_9_Shader replaceUI:true version:1(…)
Parameters use the name defined in the effect file You could still use “showproperties
meditmaterials[1]” to list the names Simply use the delegate keyword to set the
value The texture used by effects is actually a bitmap
type
Extending with MAXScript
On Create Handler (Scripted_StandardFX.ms)
on create do(
-- setup initial materialeffectfile = GetDir #maxroot effectfile = effectfile + "\\maps\\fx\\
StandardFX.fx"delegate.effectfile = effectfileambientlock = true
)
Extending with MAXScript
Button Handler (Scripted_StandardFX.ms)
on b_topDiffuseClr pressed do(
b = selectbitmap caption: "Top Diffuse Map" if b != undefined then (
delegate.g_TopTexture = b b_topDiffuseClr.text = b.filename topdiffuseMap = b --defined as
type:#bitmap )
)
Extending with MAXScript
Generates custom and sophisticated UIs Allows data validation and Access control
E.g. power of two textures, or textures no greater than a certain size.
Can provide workarounds for the UI widgets generated by the parsers
Scriptable values instead of UI generated can drive delegate values E.g. UV clamping etc..
Things to remember
Annotations are case sensitive The three built in parsers are very different, don’t
mix up your annotations Type verses ResourceType name verses ResourceName
3ds max is Z-up You soon find this out with cubemaps!! Swap YZ around to make it work
Currently only camera based matrixes are support at the object level.
Use Scripted materials Good to work around “Auto UI” look and feel Data management/validation
Resources
http://sparks.autodesk.com Sample parsers available and documentation
http://developer.nvidia.com http://www.ati.com/developer msdn.microsoft.com/directx Ben Cloward
http://www.monitorstudios.com/bcloward/resources.html
neil.hazzard@autodesk.com
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