没有合适的资源？快使用搜索试试~ 我知道了~

文库首页开发技术其它OpenGL Geometry Shader Tutorial（OpenGL几何着色器教程）

OpenGL Geometry Shader Tutorial（OpenGL几何着色器教程）

OpenGL

Geometry

Shader

几何着色器

4星 · 超过85%的资源需积分: 50 179 下载量 85 浏览量 2010-04-05 14:42:41 上传评论 2 收藏 515KB PDF 举报

温馨提示

试读

24页

The OpenGL Geometry Shader Tutorial from Oregon State University，it's cool...

资源详情

资源评论

GLSL Geometry Shaders

Mike Bailey

Mike

Bailey

Oregon State University

mjb – May 10, 2009

Vertices

CPU

Vertex

Processor

Transformed Vertices

The Geometry Shader:

Where Does it Fit in the Pipeline?

Assembled Primitive

Create New

Geometry

Assemble New

Geometry

Assemble

Geometry

mjb – May 10, 2009

Rasterizer

Fragment

Processor

Pixels

Interpolated Values

Note: a shader

program can have any

combination of vertex,

geometry, and

fragment shaders in it.

All three are not

required concurrently.

Geometry Shader:

What Does it Do?

Points, Lines, Line Strip, Line Loop,,Lines with

Adjacency, Line Strip with Adjacency, Triangles,

Triangle Strip, Triangle Fan, Triangles with

Adjacency, Triangle Strip with Adjacency

Application

generates

these

{

Geometry Shader

Point, Line, Line with Adjacency,

Triangle, Triangle with Adjacency

Driver feeds these

one-at-a-time

into the Geometry Shader

Adjacency,

Triangle

Strip

with

Adjacency

{

mjb – May 10, 2009

Points, LineStrips,

TriangleStrips

Geometry Shader

generates (almost) as

many of these as it wants

There needn’t be any correlation between Geometry Shader input type

and Geometry Shader output type. Points can generate triangles,

triangles can generate triangle strips, etc.

{

Additional Arguments are Now Available for glBegin( ):

GL_LINES_ADJACENCY_EXT

GL_LINE_STRIP_ADJACENCY_EXT

GL_TRIANGLES_ADJACENCY_EXT

GL TRIANGLE STRIP ADJECENCY EXT

mjb – May 10, 2009

TRIANGLE

STRIP

ADJECENCY

EXT

New Adjacency Primitives (and what they do by default)

Lines with Adjacency

0123

N = 1

Line Strip with Adjacency

123450

4N vertices are given.

(where N is the number of line segments to draw).

A line segment is drawn between #1 and #2.

Vertices #0 and #3 are there to provide adjacency information.

N = 1

mjb – May 10, 2009

N+3 vertices are given

(where N is the number of line segments to draw).

A line segment is drawn between #1 and #2, #2 and #3, …, #N and #N+1.

Vertices #0 and #N+2 are there to provide adjacency information.

N = 3

Triangles with Adjacency

New Adjacency Primitives (and what they do by default)

6N vertices are given

(where N is the number of triangles to draw).

Points 0, 2, and 4 define the triangle.

Points 1, 3, and 5 tell where adjacent triangles are.

N = 1

mjb – May 10, 2009

Triangle Strip with Adjacenc

4+2N vertices are given

(where N is the number of triangles to draw).

Points 0, 2, 4, 6, 8, 10, …define the triangles.

Points 1, 3, 5, 7, 9, 11, … tell where adjacent triangles are.

N = 4

glProgramParameter Must Be Called Before the Shaders are Linked

glProgramParameteriEXT( progname, GL_GEOMETRY_VERTICES_OUT_EXT, int value )

Maximum number of

vertices this Geometry

Shader will be emitting

mjb – May 10, 2009

glProgramParameter Must Be Called Before the Shaders are Linked

glProgramParameteriEXT( progname, GL_GEOMETRY_INPUT_TYPE_EXT, int value )

The primitive type that this

Geometry Shader will be

receiving

GL_POINTS

GL LINES

Could actually come from GL_LINES,

GL_LINE_STRIP, or GL_LINE_LOOP

Could actually come from

GL_LINES_ADJACENCY_EXT or

GL_LINE_STRIP_ADJACENCY_EXT

mjb – May 10, 2009

LINES

GL_LINES_ADJACENCY_EXT

GL_TRIANGLES

GL_TRIANGLES_ADJACENCY_EXT

Could actually come from GL_TRIANGLES,

GL_TRIANGLE_STRIP, or

GL_TRIANGLE_FAN

Could actually come from

GL_TRIANGLES_ADJACENCY_EXT or

GL_TRIANGLE_STRIP_ADJACENCY_EXT

glProgramParameter Must Be Called Before the Shaders are Linked

glProgramParameteriEXT( progname, GL_GEOMETRY_OUTPUT_TYPE_EXT, int value )

The primitive type that this

Geometry Shader will be sending

on to the rest of the pipeline

GL_POINTS

GL LINE STRIP

mjb – May 10, 2009

LINE

STRIP

GL_TRIANGLE_STRIP

Warning: glProgramParameteriEXT( ) calls can go into a Display List,

deferring their execution until it is too late! (Bad idea…)

This gets executed

now

GLuint dl = glGenLists( 1 );

glNewList( dl, GL_COMPILE );

. . .

program = glCreateProgram();

. . .

lPro

ramParameteriEXT

(

ram

GL GEOMETRY INPUT TYPE EXT

utGeometr

);

gg (pg,

____

,p yyp);

glProgramParameteriEXT( program, GL_GEOMETRY_OUTPUT_TYPE_EXT, outputGeometryType );

glProgramParameteriEXT( program, GL_GEOMETRY_VERTICES_OUT_EXT, 101 );

glLinkProgram( program );

glUseProgram( program );

. . .

glEndList( );

mjb – May 10, 2009

This gets executed

now

, probably with

the wrong Program Parameter settings,

generating an unexpected Link Error!

These get executed later, whenever

the display list is glCallList’ed.

Moral: If you are creating a display list from a stream of input data, defer both the setting of

Program Parameters and the Linking of the Program until after the Display List is complete.

There is rarely a good reason to have calls to glProgramParameteriEXT( ) in a display list.

剩余23页未读，继续阅读

评论收藏

内容反馈

ydnac

2012-07-05

用的比较多的是顶点着色器和片段着色器，几何着色器用的少，但是有些需要对几何模型做改动的还是得用GS，不错的学习资料。

OpenGL Geometry Shader Tutorial（OpenGL几何着色器教程）

评论9

最新资源

OpenGL Geometry Shader Tutorial（OpenGL几何着色器教程）

评论9

最新资源

相关推荐

几何着色器例子

OpenGL着色器教程资料合集

OpenGL 几何着色器 传入点,绘制三角形

计算机图形学opengl+shader几个实例

Geometry Shader（Unity几何着色器）

基于Qt和GLSL的着色器例子（演示程序）

OpenGL shader 代码，可正确编译，完美运行

OGLGeometryShader_顶点索引.rar 基础示例

Geometry-Grass-Shader:Unity引擎的几何草着色器

OpenGL3.3_GeometryShader_PointToLine.rar

OpenGL3.3_GeometryShader_VisualNormal

OpenGL3.3_GeometryShader_ExplodeEffect.rar

OpenGL3.3_GeometryShader_PointToHouse.rar

cg_geometry_program

5.8几何着色器阶段1

Chapter 12 The Geometry Shader

OpenGLGeometryShader计算三角形的法线 源码

OpenGL爆炸碎片化效果 源码

AirHockeyTouch1.rar

glslang-master-windows-x64-Release.zip

GLSLangSpec.4.50.diff.pdf

3DMAX几何投影插件Geometry Projection

Geometry Shader全国独家披露——性能提升6-8倍？GPU架构大革新！.pdf

[OpenGL] OpenGL 开发超级圣经 (英文版)

OpenGL SuperBible 5th Edition.pdf

Qt 5实现串口调试助手 （源工程文件、0积分下载）

【SystemVerilog】路科验证V2学习笔记（全600页）.pdf

AutoSAR标准协议4.2.2

OpenGL 几何着色器传入点,绘制三角形

OpenGLGeometryShader计算三角形的法线源码

OpenGL爆炸碎片化效果源码

Qt 5实现串口调试助手（源工程文件、0积分下载）