Introduction to OpenGL Introduction to OpenGL Pipeline From Pipeline From

Programmer ViewProgrammer ViewTong-Yee Lee

vertex

ModelviewMatrix

ProjectionMatrix

PerspectiveDivision

ViewportTransform

Modelview

Modelview

Projection

object eye

clip normalizeddevice

window

OpenGL Transformation OpenGL Transformation PipelinePipeline

glTranslate{fd}( glTranslate{fd}( x, y, zx, y, z ) )

glRotate{fd}( glRotate{fd}( angle, x, y, zangle, x, y, z ) )

glScale{fd}( glScale{fd}( x, y, zx, y, z ) )

3D Transformations3D Transformations

OpenGL transformation OpenGL transformation MatricesMatrices

vertex

ModelviewMatrix

ProjectionMatrix

PerspectiveDivision

ViewportTransform

Modelview

Modelview

Projection

object eye

clip normalizeddevice

window

OpenGL Transformation OpenGL Transformation PipelinePipeline

gluLookAt( eyegluLookAt( eyexx, eye, eyeyy, eye, eyezz,, aim aimxx, aim, aimyy, aim, aimzz,, up upxx, up, upyy, up, upzz ) )

tripod

Changes of Coordinate Changes of Coordinate SystemSystem

World coordinate system

Camera (eye) coordinate system

vertex

ModelviewMatrix

ProjectionMatrix

PerspectiveDivision

ViewportTransform

Modelview

Modelview

Projection

object eye

clip normalizeddevice

window

OpenGL Transformation OpenGL Transformation PipelinePipeline

model

viewingvolume

Perspective Perspective projectionprojectionOrthographic Orthographic parallel projectionparallel projection

Perspective projectionPerspective projectiongluPerspective( gluPerspective( fovy, aspect, zNear, zFarfovy, aspect, zNear, zFar ) )

glFrustumglFrustum(( left,left, right,right, bottom,bottom, top,top, zNear,zNear, zFarzFar ))

Orthographic parallel projectionOrthographic parallel projectionglOrtho(glOrtho( left,left, right,right, bottom,bottom, top,top, zNear,zNear, zFarzFar ))

gluOrtho2D( gluOrtho2D( left, right, bottom, topleft, right, bottom, top ) )

vertex

ModelviewMatrix

ProjectionMatrix

PerspectiveDivision

ViewportTransform

Modelview

Modelview

Projection

object eye

clip normalizeddevice

window

glViewport( 0, 0, (GLsizei) w, (GLsizei) h );glViewport( 0, 0, (GLsizei) w, (GLsizei) h );ww

hh

glMaterialfv( glMaterialfv( face, property, valueface, property, value ); );

glLightfv( glLightfv( light, property, valuelight, property, value ); );

glNormal3f( glNormal3f( x, y, zx, y, z ) )

64

Depth Buffering andHidden Surface Removal

12

48

16

12

48

16ColorBuffer

DepthBuffer

Display