A Perceptron laser scanner scanned the original fan blade, and generated a point cloud with around 2.2 million points that was brought into DSSP software.	DSSP software was used to automatically generate a NURBS surface model, which could be imported into Pro/ENGINEER software.

see http://www.geomagic.com/en

MPEG-4 Visual specifies support for animated face and body models within the Simple Face Animation and simple FBA ( Face and Body A nimation )

a face model described by Facial Definition Parameters ( FDPs ) and animated using Facial Animation Parameters ( FAPs ).
body is described by body animation parameters ( BAP )



See also http://coven.lancs.ac.uk/mpeg4/

• produce nearly identical outputs in various hardware platforms
• no user-input commands in core
• no high-level commands for 3-D objects, one must build model from primitives -- points, lines, and polygons
• OpenGL Utility Library ( GLU ) provides many modeling features,

	glBegin( GL_POINTS );
	  glVertex2i( 100, 40 );
	  glVertex2i( 120, 50 );
	  glVertex2i( 140, 80 );
	glEnd();
	

glVertex2i ( 7, 11 );
glVertex2f ( 7.0, 11.0 );
are the same

• 'v' indicates vector format
• absence of 'v' indicates scalar format
  
• Example: glColor3f( 1.0, 0.0, 0.0 );
  
  GLfloat color_array[] = {1.0, 0.0, 0.0};
  glColor3fv( color_array );

  glBegin ( GL_POLYGON );
    glVertex2f(0.0, 0.0);
    glVertex2f(0.0, 3.0);
    glVertex2f(4.0, 3.0);
    glVertex2f(6.0, 3.0);
    glVertex2f(4.0, 3.0);
  glEnd();
  

set the width in pixels for rendered point; size > 0.0, default is 1.0
• Antialiasing disabled ( default )
  fractional widths are rounded to integer widths
  if size = 2, the dot is 2 pixels by 2 pixels
• Antialiasing enabled
  a circular group of pixels is drawn

• Wide Lines
  void glLineWidth( GLfloat width ); set the width in pixels for rendered line; width > 0.0, default is 1.0
  Antialiasing disabled ( default )
  fractional widths are rounded to integer widths ( pixels )
  Antialiasing enabled
  fractional line widths are possible
  
  
• Stippled Lines
  dotted or dashed lines
  void glLineStipple ( GLint factor, GLushort pattern );
  sets the current stippling pattern for lines
  pattern is 16-bit number that sets the pattern, 1 => drawing; 0 => no drawing
  facotr ( 1 to 256 ), for repeating pattern
  Example: glLineStipple(1, 0x3F07 );
  glEnable( GL_LINE_STIPPLE );
  0x3F07 = 0011 1111 0000 0111 ( binary )
  a line would be drawn with 3 pixels on, 5 off, 6 on, 2 off
  
  glLineStipple(2, 0x3F07 );
  a line would be drawn with 6 pixels on, 10 off, 12 on, 4 off

/* * lines.c * This program demonstrates geometric primitives and * their attributes. */ #include <GL/glut.h> #include <stdlib.h> #define drawOneLine(x1,y1,x2,y2) glBegin(GL_LINES); \ glVertex2f ((x1),(y1)); glVertex2f ((x2),(y2)); glEnd(); void init(void) { glClearColor (0.0, 0.0, 0.0, 0.0); glShadeModel (GL_FLAT); } void display(void) { int i; glClear (GL_COLOR_BUFFER_BIT); /* select white for all lines */ glColor3f (1.0, 1.0, 1.0); /* in 1st row, 3 lines, each with a different stipple */ glEnable (GL_LINE_STIPPLE); glLineStipple (1, 0x0101); /* dotted */ drawOneLine (50.0, 125.0, 150.0, 125.0); glLineStipple (1, 0x00FF); /* dashed */ drawOneLine (150.0, 125.0, 250.0, 125.0); glLineStipple (1, 0x1C47); /* dash/dot/dash */ drawOneLine (250.0, 125.0, 350.0, 125.0); /* in 2nd row, 3 wide lines, each with different stipple */ glLineWidth (5.0); glLineStipple (1, 0x0101); /* dotted */ drawOneLine (50.0, 100.0, 150.0, 100.0); glLineStipple (1, 0x00FF); /* dashed */ drawOneLine (150.0, 100.0, 250.0, 100.0); glLineStipple (1, 0x1C47); /* dash/dot/dash */ drawOneLine (250.0, 100.0, 350.0, 100.0); glLineWidth (1.0); /* in 3rd row, 6 lines, with dash/dot/dash stipple */ /* as part of a single connected line strip */ glLineStipple (1, 0x1C47); /* dash/dot/dash */ glBegin (GL_LINE_STRIP); for (i = 0; i < 7; i++) glVertex2f (50.0 + ((GLfloat) i * 50.0), 75.0); glEnd (); /* in 4th row, 6 independent lines with same stipple */ for (i = 0; i < 6; i++) { drawOneLine (50.0 + ((GLfloat) i * 50.0), 50.0, 50.0 + ((GLfloat)(i+1) * 50.0), 50.0); } /* in 5th row, 1 line, with dash/dot/dash stipple */ /* and a stipple repeat factor of 5 */ glLineStipple (5, 0x1C47); /* dash/dot/dash */ drawOneLine (50.0, 25.0, 350.0, 25.0); glDisable (GL_LINE_STIPPLE); glFlush (); } void reshape (int w, int h) { glViewport (0, 0, (GLsizei) w, (GLsizei) h); glMatrixMode (GL_PROJECTION); glLoadIdentity (); gluOrtho2D (0.0, (GLdouble) w, 0.0, (GLdouble) h); } void keyboard(unsigned char key, int x, int y) { switch (key) { case 27: exit(0); break; } } int main(int argc, char** argv) { glutInit(&argc, argv); glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB); glutInitWindowSize (400, 150); glutInitWindowPosition (100, 100); glutCreateWindow (argv[0]); init (); glutDisplayFunc(display); glutReshapeFunc(reshape); glutKeyboardFunc(keyboard); glutMainLoop(); return 0; }

a polygon is a plane figure specified by a set of 3 or more vertices ( coordinate positions )
simple ( standard ) polygons -- polygons whose edges do not cross
back face -- the side of a polygon that faces into the object interior
front face -- the visible, outward side

Each polygon in a scene is contained within a plane of infinite extent

A x + B y + C z + D = 0 where ( x, y, z ) is any point on the plane
  if A x + B y + C z + D < 0 , the point ( x, y, z ) is behind the plane if A x + B y + C z + D > 0 , the point ( x, y, z ) is before the plane


• Typically drawn by filling in all pixels enclosed within the boundary ( default ) glPolygonMode( GL_FRONT, GL_FILL );
  glPolygonMode( GL_BACK, GL_FILL );
  
• Can also draw them as outlined polygons glPolygonMode( GL_FRONT, GL_LINE );
  
• Or simply drawn as points glPolygonMode( GL_FRONT, GL_POINT );
  
• A filled polygon might be solidly filled or stippled with a certain pattern
   
• By convention polygons whose vertices appear in counterclockwise order on screen are called front-facing but users can also make clockwise order as front-facing glFrontFace( GL_CCW );     //counterclockwise
  glFrontFace( GL_CW );     //clockwise Orientation of vertices is also known as winding.
   
• Culling -- discarding ( ignore ) invisible polygons during rendering
  e.g. back faces of an enclosed opaque polygon
  enableb by glEnable( GL_CULL_FACE );
  glCullFace ( GL_FRONT );
  glCullFace ( GL_BACK );
  glCullFace ( GL_FRONT_AND_BACK );
  Class Exercise:

  glEnable( GL_CULL_FACE ); glCullFace ( GL_BACK ); glColor3f( 1.0, 0.0, 0.0 ); //red glFrontFace ( GL_CCW ); glPolygonMode( GL_FRONT, GL_FILL ); glBegin( GL_POLYGON ); //draw solid polygon glVertex2i( 0, 0 ); glVertex2i( 0, 100 ); glVertex2i( 100, 100 ); glVertex2i( 100, 0 ); glEnd();

  What do you expect to see on the display, assuming everything has been initialized properly?

• Area

  	n-1
  A = ½		xi yi+1 - xi+1 yi
  	i=0

  where i + 1 is taken mod n.
  for GL_CCW, if A > 0,     => front-facing, otherwise back-facing
  for GL_CW, if A < 0,     => front-facing, otherwise back-facing

• Stippling Polygons glEnable ( GL_POLYGON_STIPPLE ); setting pattern by void glPolygonStipple( const Glubyte *mask );
  mask is a 32 x 32 pattern of bits
  aligned with the window, thus rotate the polygon won't rotate the stipple pattern

• Examples
  Drawing polygons with different modes
  

  int x0, y0; glColor3f( 1.0, 0.0, 0.0 ); //red glPolygonMode( GL_FRONT, GL_FILL ); glBegin( GL_POLYGON ); //draw solid polygon glVertex2i( 10, 10 ); glVertex2i( 100, 10 ); glVertex2i( 150, 50 ); glVertex2i( 100, 100 ); glVertex2i( 50, 80 ); glVertex2i( 10, 10 ); glEnd(); x0 = 160; glColor3f( 0.0, 1.0, 0.0 ); //green glPolygonMode( GL_FRONT, GL_LINE ); glBegin( GL_POLYGON ); //draw polygon glVertex2i( x0+10, 10 ); glVertex2i( x0+100, 10 ); glVertex2i( x0+150, 50 ); glVertex2i( x0+100, 100 ); glVertex2i( x0+50, 80 ); glVertex2i( x0+10, 10 ); glEnd(); x0 = 80; y0 = 120; glColor3f( 0.0, 0.0, 1.0 ); //blue glPolygonMode( GL_FRONT, GL_POINT ); glBegin( GL_POLYGON ); //draw polygon points glVertex2i( x0+10, y0+10 ); glVertex2i( x0+100, y0+10 ); glVertex2i( x0+150, y0+50 ); glVertex2i( x0+100, y0+100 ); glVertex2i( x0+50, y0+80 ); glVertex2i( x0+10, y0+10 ); glEnd();