Upload
shon-black
View
220
Download
2
Tags:
Embed Size (px)
Citation preview
Light Hearted Look At
GPU Programming And Linear Algebra Operators
Pass Out (3) PapersAnd GPUGems Book
Book Has Some Nice Graphics
Demos
Pyramids DemoBlackbox
Codecreatures Demo
Benchmarks!
What Are The Differences Between These Demos?
Food For Thought
Science/Education Versus Entertainment?
“Edutainment”?
Is “User Friendliness” The Same?
To Me, The Codecreatures Demo Was State Of The Art!Probably To Some Video Gamers, It’s Old Hat!
I Assume This Code Is Really Taking Advantage Of The GPU
“The Continuum”
Assembly Programming “GPU Programming” Monitor Programming 4GL, 5GL, …?
User Friendliness
small medium large
What, Exactly, Is Happening On The GPU? Probably Don’t Know Exactly
SDKS e.g.
Visual Studio
My ContinuumGPU Knowledge
small medium large
Me Prof Bailey (andProf Zhang andJacob)
;-) :-)
What’s On the GPU,What’s on the CPU?
“Don’t Ask Me!”
Is the GPU Synonymous With the Graphics Card?
“Yes, close enough. The GPU is actually the processor chip that lives on the graphics card. The "graphics card" has a bunch of other stuff on it to support the GPU and its operations, plus memory, bus interaction, etc.”
Mike Bailey
GonnaWear ThisOne Out!
GPU/Graphics Card?
CPU,Bus,VP,FP,bunchof other stuff
Benchmarking
(CPU)
(BUS)
Benchmarking
(VP)
(FP)
Science?
Entertainment?
Benchmarking
glFinish(); int t0 = glutGet( GLUT_ELAPSED_TIME );
<< All Graphics Calls That You Are Testing The Speed Of >>
glFinish(); int t1 = glutGet( GLUT_ELAPSED_TIME ); glutSwapBuffers(); fprintf( stderr, "One display frame took %d milliseconds\n", t1 - t0 );
What’s On the GPU,What’s On the CPU?
How Well Do We Know The Hardware/Software Boundary?
// minimal vertex shader// www.lighthouse3d.com
void main(){
// the following three lines provide the same result
// gl_Position = gl_ProjectionMatrix * gl_ModelViewMatrix * gl_Vertex;// gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
gl_Position = ftransform();}
The end result is of course the same. Does this guarantee the same transformation as in the fixed functionality? Well in theory yes, but in practice the process of transforming the vertices may not follow the same order as in
here. This is normally a highly optimized task in a graphic card, and a special function is provided to take advantage of that optimization. Another reason for this function is due to the limit in the precision of the float data type. When calculus is done in different orders, different results may be obtained due to this limited precision. Hence the GLSL provides a function that guarantees that not only the best performance is obtained but also that the result is always the same as when using the fixed functionality. This magical function is:
vec4 ftransform(void);
This function returns the transformed incoming vertex, following the same steps as the fixed functionality does.
http://www.lighthouse3d.com/opengl/glsl/index.php?minimal
Jumping Ahead:Specific Code,But TakeawayIs Some UncertaintyIn Implementation
Simplest Shader Program You Will Ever See!
GPU Overview
What is the GPU?
“Graphical Processing Unit”
HowWe Gonna Dive In?
GLSL - (Relatively) User Friendly
GLman - User Friendly
Good Demos Available (e.g. Pyramids)
GLSL/GLman Orientation
(Simple, Less Powerful, Less User Friendly Visual Studio Demos/Prototypes Do Exist And Will Be Overviewed
GLSL/GLman Orientation
“GLman is written in OpenGL. It is meant to be a scripting system to make it easy to explore GPU programming, so internally it takes care of a lot of theboilerplate of writing GPU-based programs, leaving you just to write the GPU code. So, the .glib files are the script, and the .vert and .frag files are the vertex and fragment GPU code.”
Mike Bailey
http://web.engr.oregonstate.edu/~mjb/cs519/Handouts/Glman/glman.pdf
Glman Lets You Concentrate On:
Vertex Processor - .vert file // text file
Fragment Processor - .frag file // text file
GLSL/GLman Orientation
GLSL/GLman Orientation
Glman makesthis part easy
GLSL/GLman Orientation
Simple/Standalone Visual Studio Demo AppsAvailable, AndWill Be LookedAt
Why Use the GPU?
“The rasterizer is a part of the GPU, but its functionality can't becustomized by the user, other than sending user-defined variablesthrough it to be interpolated.”
Mike Bailey
Rasterizer In The“Bunch Of Other Stuff”Category ?
GPU versus CPU
“The distinction is becoming more and more blurred, but the basic difference is that GPUs have certain architectural changes that appeal more to graphics, such as more cores, less cache,and special texture fetching hardware.”
Mike Bailey
Can’t Do Recursion On The GPU!!!
GPU versus CPU
Can’t Do Recursion On The GPU!!!
CPU – double oriented
GPU – float oriented
Multi Cores Parallelism
Less Cache Streaming
Texture (Local) Memory Reduced Bus Activity
GPU versus CPU
http://www.springerlink.com/content/eupfj7euk0jvj98u/fulltext.pdf
[Chiang, Hsueh, Liu]
GPU versus CPU
GPU versus CPU
We’ll take a quick look at these (mostly linear operator) terms shortly
http://ieeexplore.ieee.org/iel5/4221378/4221379/04221459.pdf?tp=&isnumber=&arnumber=4221459
[Gong, Langille, Gong]
GPU Typical Programming Environment
GLSL - OpenGL Shading Language
HLSL - DirectX's high-level shading language
Cg – C For Graphics
…
Vertex Shader Program(ming)
Fragment Shader Program(ming)
each with a main()
examples shortly
Specific Linear Operators
Matrices for Multiplication
Matrices for Differentiation – e.g. Sobel Filter
Specific Linear Operators
vec2 texcoord1, texcoord2;vec3 position;vec4 myRGBA;ivec2 textureLookup;bvec3 less;
Data Types
Specific Linear Operators
mat2 mat2D;mat3 optMatrix;mat4 view, projection;mat4x4 view; // an alternate way of declaring a mat4mat3x2 m; // a matrix with 3 columns and 2 rows
Data Types
Specific Linear Operators
vec3(float) // initializes each component of with the floatvec4(ivec4) // makes a vec4 with component-wise conversionvec2(float, float) // initializes a vec2 with 2 floatsivec3(int, int, int) // initializes an ivec3 with 3 intsbvec4(int, int, float, float) // uses 4 Boolean conversionsvec2(vec3) // drops the third component of a vec3vec3(vec4) // drops the fourth component of a vec4vec3(vec2, float) // vec3.x = vec2.x, vec3.y = vec2.y, vec3.z = floatvec3(float, vec2) // vec3.x = float, vec3.y = vec2.x, vec3.z = vec2.yvec4(vec3, float) // We’’ll See An Application Of One Of Thesevec4(float, vec3) // Or Something Similarvec4(vec2, vec2)
Constructors
Specific Linear Operators
http://www.opengl.org/registry/doc/GLSLangSpec.Full.1.20.8.pdf
Specific Linear Operators
Testing/Benchmarking
Specific Linear Operators
Testing/Benchmarking
Specific Linear Operators
Non Linear
Testing/Benchmarking
Specific Linear Operators
SWIZZLING!
Specific Linear Operators
// different denominator forms
Specific Linear Operators
Specific Linear Operators
http://wwwcg.in.tum.de/Research/data/Publications/sig03.pdf
[Kruger,Westermann]
Specific Linear Operators
Basic Architecture View
Input Is (C/C++ Program), .vert file, .frag file (, .glib file)
Output Is Image(s)
More Complex Architecture Views
Another Pipeline Overview
MC – Model Coordinates
SC – Screen Coordinates
CompleteColored Screen
Coordinates
Another Pipeline Overview
“Programmable Unit”
OverSimplified?
MC – Model Coordinates
SC – Screen Coordinates
Colored Screen Coordinates
Snazzy Examples
Snazzy Examples
Snazzy Examples
Snazzy Examples
Getting Started
GLSL/GLman
Demos
Start -> Programs -> Shaders -> Glman
http://cs.oregonstate.edu/~mjb/cs519
has multiple sets of input files (.glib, .vert, and .frag)
(In e.g. CGEL)
Pyramids
- pyramids.glib
- pyramids.vert
- pyramids.frag
GLSL/Glman Specialization
GLSL/Glman Specialization
##OpenGL GLIB
Perspective 70
Vertex pyramids.vertFragment pyramids.fragProgram BumpMapTest \
LightX <-10. 0. 10.0> \LightY <-10. 10. 10.0> \LightZ <-10. 10. 10.0> \SurfaceColor {0.7 0.8 0.1 1.} \Ang <-3.14159 0.785398 3.14159> \BumpDensity <5. 16. 100.> \Ambient <0. 0.1 .4> \Height <-.06 .005 .06>
Sphere 1 200 200#Obj cow.obj#Teapot
pyramids.glib
##OpenGL GLIB
Perspective 70
Vertex pyramids.vertFragment pyramids.frag
Program BumpMapTest \LightX <-10. 0. 10.0> \LightY <-10. 10. 10.0> \LightZ <-10. 10. 10.0> \SurfaceColor {0.7 0.8 0.1 1.} \Ang <-3.14159 0.785398 3.14159> \BumpDensity <5. 16. 100.> \Ambient <0. 0.1 .4> \Height <-.06 .005 .06>
Sphere 1 200 200#Obj cow.obj#Teapot
“one to one”
Pyramids.glib
vert filefrag file
“one to one”
Getting Started
http://www.lighthouse3d.com/opengl/glsl/index.php?minimal
http://www.lighthouse3d.com/opengl/glsl/examples/glutglsl5_2.0.zip
has VS Project (glutglsl) that compiles (e.g. in CGEL) (needs glew32.lib which can be copied from the local hard drive)
Another Approach
void setShaders() {
char *vs = NULL,*fs = NULL,*fs2 = NULL;
v = glCreateShader(GL_VERTEX_SHADER);f = glCreateShader(GL_FRAGMENT_SHADER);f2 = glCreateShader(GL_FRAGMENT_SHADER);
vs = textFileRead("minimal.vert");fs = textFileRead("minimal.frag");
const char * vv = vs;const char * ff = fs;
glShaderSource(v, 1, &vv,NULL);glShaderSource(f, 1, &ff,NULL);
free(vs);free(fs);
glCompileShader(v);glCompileShader(f);
printShaderInfoLog(v);printShaderInfoLog(f);printShaderInfoLog(f2);
p = glCreateProgram();glAttachShader(p,v);glAttachShader(p,f);
glLinkProgram(p);printProgramInfoLog(p);
glUseProgram(p);
}
“THE CODE !!!”
(“THE SYNTAX”?)
// minimal vertex shader// www.lighthouse3d.com
void main(){
// the following three lines provide the same result
// gl_Position = gl_ProjectionMatrix * gl_ModelViewMatrix * gl_Vertex;// gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
gl_Position = ftransform();}
The end result is of course the same. Does this guarantee the same transformation as in the fixed functionality? Well in theory yes, but in practice the process of transforming the vertices may not follow the same order as in here. This is normally a highly optimized task in a graphic card, and a special function is provided to take advantage of that optimization. Another reason for this function is due to the limit in the precision of the float data type. When calculus is done in different orders, different results may be obtained due to this limited precision. Hence the GLSL provides a function that guarantees that not only the best performance is obtained but also that the result is always the same as when using the fixed functionality. This magical function is:
vec4 ftransform(void);
This function returns the transformed incoming vertex, following the same steps as the fixed functionality does.
// minimal fragment shader// www.lighthouse3d.com
void main(){
gl_FragColor = vec4(0.4,0.4,0.8,1.0); What Color Is This?}
// minimal vertex shader// www.lighthouse3d.com
void main(){
// the following three lines provide the same result
// gl_Position = gl_ProjectionMatrix * gl_ModelViewMatrix * gl_Vertex;// gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
gl_Position = ftransform();}
CTRL-ALT-PRINT_SCREEN
PASTE INTO PAINT
SAVE AS 24 BIT BMP
RIGHT CLICK FILEOPEN WITH PHOTOSHOP
TEARDROPPER TOOL
DOUBLE CLICK
102 = .4 * 255102 = .4 * 255204 = .8 * 255
// minimal fragment shader// www.lighthouse3d.com
void main(){
gl_FragColor = gl_Color ; // varying vec4 gl_Color;}
// minimal vector shader// www.lighthouse3d.com
void main(){
gl_FrontColor = gl_Color; // attribute vec4 gl_Color;
gl_Position = ftransform();}
// “near” minimal vertex shader// www.lighthouse3d.com
varying vec3 lightDir,normal;
void main(){
lightDir = normalize(vec3(gl_LightSource[0].position));normal = gl_NormalMatrix * gl_Normal;
gl_Position = ftransform();}
// “near” minimal fragment shader// www.lighthouse3d.com
varying vec3 lightDir,normal;
void main(){
float intensity;vec4 color;
// normalizing the lights position to be on the safe sidevec3 l = normalize(vec3(gl_LightSource[0].position));
vec3 n = normalize(normal);
intensity = dot(l,n);
if (intensity > 0.95)color = vec4(1.0,0.5,0.5,1.0);
else if (intensity > 0.5)color = vec4(0.6,0.3,0.3,1.0);
else if (intensity > 0.25)color = vec4(0.4,0.2,0.2,1.0);
elsecolor = vec4(0.2,0.1,0.1,1.0);
gl_FragColor = color;}
ShaderPseudo Lighting
Real Utility?
Exploiting(Living With)ExistingArchitecture/HardwareThat’s BeyondProgrammaticControl
// Special Constructor
Context
Context
Exploiting(Living With)ExistingArchitecture/HardwareThat’s BeyondProgrammaticControl
Context
// We Saw An // Example
Context
Miscellaneous
“Programmable Unit”
Miscellaneous
“Programmable Unit”
Did You See All 3 PapersAnd The Book?
Questions?
GLUTGLSL Demo
z:\Windows.Documents\Desktop\colorglut_2.0\Debug>glutglsl