NAME

surfcar, surfegg − surface editor and rendering driver

SYNOPSIS

/usr/people/mexdemos/surfcar
/usr/people/mexdemos/surfegg

DESCRIPTION

surfcar and surfegg are interactive bicubic patch editors.  It allows the user to manipulate the locations and numbers of basis points defining a bicubic B-spline surface.  The user can also establish planes of symmetry, manipulate the splined object for study from various points of view, and send the basis points to a second program that draws smooth-shaded, z-buffered objects. 

The default data base specifies a surface shape more or less resembling an automobile or egg carton. 

The simplest use of the program allows you to edit the displayed surface by manipulating its basis points.  The program takes a while to start up.  It displays a wait cursor until it does. 

The program uses screen buttons and cursor glyphs.  In the initial state,  the cursor is shaped like the mouse.  LEFTMOUSE gives a stylized arrow in the ’X’ direction, MIDDLEMOUSE one in ’Y’, and RIGHTMOUSE one in ’Z’.  The mouse can be used to pick a basis point, select an axis, and move the point along that axis.  Any basis point can be picked either at its “real” location in space or at its projection on any of the index surfaces. 

The rightmost five screen buttons help edit the surface.  The leftmost two help view it. 

The leftmost screen window shows three mutually perpendicular axes.  If an axis is selected by the cursor, RIGHTMOUSE will rotate the surface about that axis.  The index planes will stay still while the surface rotates ninety degrees around the axis selected. 

The stylishly bloodshot eye allows rotation of the object and the index planes.  LEFTMOUSE allows rotation of the surface alone.  RIGHTMOUSE returns it to its original spot.  RIGHTMOUSE allows rotation of the object and axes.  Pressing RIGHTMOUSE again gets out of the rotate mode and leaves the display at its new position.  LEFTMOUSE, while the object is in rotate mode, transmits the current surface to the surface rendering demonstration program, zshadecar(1D).

Use the five screen buttons on the lower right to make more modifications to the surface.  Each of the three rightmost buttons (the cubes with slices down the middle) selects a plane of symmetry across the surface.  Only two planes of symmetry can be relevant for any orientation of the object.  Attempts to select the impossible plane will not be accepted and will blink an error cursor.  The remaining two buttons double the number of basis points in the image along the axes indicated.  More points allow a more complicated surface. 

WINDOW MANAGER

Versions for use with and without the window manager are supplied.  The version with the window manager is the only one that communicates directly with zshadecar(1D).

SEE ALSO

zshadecar(1D)

AUTHOR

Henry Moreton
 

Version 2.4  —  May 08, 1986