Meshview README
                       Department of Computer Science
	                     Indiana University
                          (c)  1994, 1998, 1999


INTRODUCTION
-------------

This is Meshview, an interactive viewing program for viewing curves
and two-dimensional manifolds embedded in 3D or 4D. It is written in
OpenGL and X/Motif. It has been successfully compiled on the SGI under
IRIX 5.2-6.5, SOLARIS 2.6, and Linux 2.2.2, and should be able to run
on any workstation that supports OpenGL and X/Motif.


FEATURES
--------

-- Reads Geomview/OOGL (developed at the Geometry Center, University of 
   Minnesota) MESH, OFF and LIST file formats, plus the additional
   DOT, LINE, LINE_STRIP, LINE_LOOP, and  FRAMES formats.

-- Rotates/translates/scales objects in 3D and 4D interactively under 
   mouse control.

-- Applies 3D and 4D rolling ball models to accomplish rotations.
   (See Technical Reports 319 and 406, Computer Science Department,
    Indiana University, available by anonymous ftp from
    ftp.cs.indiana.edu in the directory pub/techreports)

-- Momentum option available on all motions.

-- Optionally draws faces, edges, vertices, normals, palette, 
   a single lighting vector, a reference unit sphere,
   and a reference set of 4D axes.

-- Supplies a wide range of color palette options for 4D depth color coding.

-- Supplies an interactive parametric space "picker" (or point locator)
   for a MESH file or list of MESH files.  Any individual mesh in
   a set of loaded patches can be selected in turn.

-- Supplies an interactive quaternion rotation utility taking
   any 3D rotation in the subwindow and converting it to a quaternion
   multiplication applied to all 4D points in the main window.

-- Saves system state for later recovery, including current 3D and 4D 
   viewing matrices, camera setting, background color, light direction 
   and rendered ppm image of the current scene.  This is useful for
   reconstructing the state of an illustration for a publication.

-- Loads palettes and saved system states.

-- Uses two different colors (or one color) for front-facing and back-facing 
   surfaces. This feature is quite useful when rotating in 4D.  Also
   provides several screen-door transparency options and a default
   checkboard texture map for MESH files.

-- Supports 3D and 4D perspective and orthogonal projections.

-- Supports a choice between applying the 4D rolling ball to the
   current screen coordinates of the object's 3D projection (context-free,
   the default), or applying to the object's local 3D coordinate
   system context (use the "axes" display to help show the context). 
   The latter is useful for looking at different sides of the object's
   3D projection while performing a 4D rotation.  This is needed
   mostly to accommodate a 2D mouse interface, and would not be
   as useful for a 3D mouse interface.

-- Supports SGI stereographics stereo display with adjustable eye
   parameters, and an optional Logitech 3D "Flying Mouse" interface.

-- Supports texture mapped MESH objects.

-- Supports keyframe animation with flexible timing and looping controls
   with the FRAMES format.

-- Includes a selection of example geometry files, including 4D flat torus, 
   Steiner surface (RP2 embedded in 4D), 4D Fermat surfaces and much more. 
   (see README file in the data directory for details)

-- Supplies online help.


FUTURE FEATURES BEING CONSIDERED
---------------------------------

-- 3D/4D geodesic generator.

-- 3D/4D manifold walker.

-- Static and dynamically recalculated 4D occlusion markings on 
   surfaces projected to 3D, like knot crossings of 3D knotted
   curves projected to 2D.

-- Automatic manifold patch sewing to support complicated ad hoc topologies.

-- Cutting using primitives like plane/sphere/cylinder/... in 3D/4D.

-- Specialized image generator for publications. 
   Antialiasing, larger-than-buffer size, true transparency, stereo pairs.

-- Support 3-manifolds embedded in 4D/5D/6D, volume rendering of
   simple tessellations.

-- Animation from files, parametric coordinate transformations, 
   3D and 4D orientation key frames, topological key frames, etc.

-- Tools for 2 and 3 complex variables.


SOME OF OUR DESIGN GOALS
------------------------

-- Fast. Use display lists in OpenGL. Enhance the Geomview/OOGL MESH 
   and OFF file formats.  User can specify color per object or
   color per vertex.

-- Small. Keep as simple and independent as possible.

-- Portable. Use OpenGL and X/Motif.

-- Freely distributable. 

-- Publication hardcopy generator and easily saveable state for later 
   recovery and refinement of a figure.

======================================================================
======================================================================


INSTALLATION
------------

Unpack the distribution package by 'zcat Meshview.x.tar.gz | tar xvf -',
or by 'gunzip Meshview.x.tar.gz' and then 'tar -xvf Meshview.x.tar'.
It will create a directory 'Meshview'.

Several executable files 'meshview.x' have already been compiled for
various machines and placed in the bin directory.  If you need to
recompile for your local configuration, go to the src directory, copy
the makefile 'Makefile.x' corresponding to your target CPU to
'Makefile', modify for your local system as necessary, and type 'make'
to produce the corresponding 'meshview.x' executable in the bin
directory.  Next, modify 'mw.x', a shell script driver for Meshview,
to include local paths and dependencies.  To get the iconification
icon to work, you may need to make a copy of 'meshview.icon' in your
personal or global '.icons' directory.


INVOCATION 
----------

Type 'mw.x <standard Motif options> <filename> ... <filename>',  where 
standard Motif options are those like : -geometry 1000x800, etc, 
and filenames can be names of geometry files, setting files or 
palette files in any order. Geometry files are loaded sequentially
and added into an object list. But only the last setting file is used
if more than one is supplied and only the last palette file is used if 
more than one is supplied. 

You can of course load files after you start Meshview, 'mw.x' is the 
simplest way to start.  Control-d is the quick shortcut to immediately
pop the data-loading dialog.  Note that all menus on the top
menu bar are "tear-off" style and can be positioned where convenient.


MOUSE/KEYBOARD CONTROLS
-----------------------

Below, (u,v) denotes the right-handed Cartesian coordinates of the mouse.
-- 3D viewing controls :  
     leftbutton   : 3D rotation (3D rolling ball)  R3(u,v)
     middlebutton : 3D translation in x-y plane    T3(u,v,0)
     rightbutton  : 3D translation along z axis    T3(0,0,-v)
     Shift+right  : 3D rotation around z axis      R2(u)

-- 3D lighting controls : (you can see the light ray by Ctrl+l)
     Ctrl+left    : 3D rotation (3D rolling ball)  R3(u,v)
     Ctrl+middle  : 3D rotation around z axis      R2(u)

-- 4D controls : 
     Shift+left   : xyw rotation (4D rolling ball)  R4(u,v,0)
     Shift+middle : xzw rotation (4D rolling ball)  R4(u,0,-v)

-- <Key>r :  (Reset)  It resets 4D and 3D matrices and 3D light direction, 
	               and it stops momentum.
-- <Key>c :  (Center) It resets 3D rotation and translation matrices,
                       and it stops momentum.
-- <Key>t :  Stops momentum.

-- <Key>F3:  (3D mouse)  Toggles 3D mouse.

-- Keyboard short-cuts for menu items :
     Ctrl+d     load data
     Ctrl+a     add data
     Ctrl+t     load texture
     Ctrl+l     load palette
     Ctrl+e     load setting
     Ctrl+f     save setting
     Ctrl+i     save as ppm
     Esc        quit

     <Key>f     toggle drawing of faces (default on)    
     <Key>e     toggle drawing of edges (default off)
     <Key>v     toggle drawing of vertices (default off)    
     <Key>n     toggle drawing of normals (default off)        
     <Key>u     toggle drawing of unit sphere (default off)        
*    <Key>i     toggle drawing of 2D complex plane (default off)        
     <Key>p     toggle drawing of palette (default off)        
     <Key>l     toggle drawing of lighting (default off)        
     <Key>a     toggle drawing of axes (default off)        

     <Key>1     draw two sides of face use same color (default)
     <Key>2     draw two sides of face use different color 
     <Key>3     4D depth color coding (show the palette with <Key>p)
     <Key>4     use texture (checkerboard default)
     
     <Key>5     screen door off
     <Key>6     screen door positive
     <Key>7     screen door negative

     Ctrl+g     smooth shading (default)
     Ctrl+h     flat shading

     Ctrl+p     3D perspective projection (default)
     Ctrl+o     3D orthogonal projection

     <Key>w     projecting along w-axis from 4D to 3D (default)
     <Key>x     projecting along x-axis from 4D to 3D
	        (rotating the objects in x-w plane by 90 degrees
                 before apply other 4D rotations)
     <Key>y     projecting along y-axis from 4D to 3D
	        (rotating the objects in y-w plane by 90 degrees
                 before apply other 4D rotations)
     <Key>z     projecting along z-axis from 4D to 3D
	        (rotating the objects in z-w plane by 90 degrees
                 before apply other 4D rotations)

     Shift+o     4D orthogonal projection (default)
     Shift+p     4D polar projection
                 (adjust with 'polar distance' scale on 'setting panel')

     Ctrl+m     toggle momentum (default on)
     Ctrl+q     toggle context-free (default on)
     Ctrl+s     toggle stereo mode (default off)

     Shift+v    pop up view setting panel
     Shift+s    pop up setting panel
     Shift+k    pop up picker panel
     Shift+q    pop up quaternion rotation panel
     Shift+f    pop up  key frame panel


LEARNING THE ROLLING BALL
-------------------------

To understand the basic philosophy of the rolling ball interface, 
start with a 3D object such as square.3mesh.  Use only the left 
mouse button (3D rolling ball): pulling the mouse in the +x 
(screen-right) direction tilts the 2D object so that the left edge 
comes towards the viewer, acquiring positive z-components, and the 
right edge dips away from the viewer into the screen, acquiring 
negative values of z. Pushing the mouse in the +y direction 
(screen-up) tilts the lower edge out into positive z and the upper 
edge into the screen in the negative z direction.
  Now load a solid 3D object like sphere.3mesh or torus.3mesh.
These objects automatically have vanishing 4th components (call it w) 
at every point when loaded, just as the flat objects had vanishing 
z-components.  Now use only the SHIFT-LEFT (4D rolling ball) mouse 
button:  pulling the mouse in the +x (screen-right) direction tilts
the 3D object in 4D so that the left side is acquiring a positive
w component and getting squashed in x, while the right side is tilting
away in w, getting a negative w component.  Turn on 4D depth pseudo-
coloring to make this dramatically apparent (<Key>3, Ctrl+p) - the left 
side turns red while the right turns blue with the default colormap.
Pulling the mouse in the +y direction (screen-up) gives the bottom a 
positive w and the top a negative w component while squashing the 
whole object in the y direction. The shift-left mouse control 
generates x-w and y-w 4D rolling ball rotations.  Now use only the 
SHIFT-MIDDLE mouse button, which generates x-w and z-w 4D rolling ball 
rotations.  Moving the mouse in the +x direction has the same effect as 
shift-left, but pulling the mouse down (screen-down direction) pushes 
the BACK side of the object out into positive w, and the FRONT side 
acquires a negative w component. pushing the mouse up (screen-up 
direction) has the opposite effect.
  If a 3D mouse is available, all 3 of these motions, or any linear
combination, are available at once and the splitting into the two
shift-left and shift-middle controls is not needed.  The default mode,
in which all 4D rolling ball motions are referred to the screen-based
xyz coordinate system with z out of the screen, is the most natural
one to emulate a 3D mouse.  However, when only a 2D mouse is available,
an alternate mode is provided that can be quite useful:  deactivate the
"Context_free" check box on the "Motion" menu.  This will allow the user 
to rotate the object to any 3D orientation (using mouse-left or mouse-
shift-right), but now shift-left will follow the object's original x-y 
axes, and rotate the object in 4D as though the 2D mouse were a 3D mouse
moving in the object's own original x-axis direction, NOT the current 
screen x.  Analogous behavior occurs for y motions and for shift-middle 
x and y mouse motions. Turn on the drawing of xyzw axes to see the
different effects.


GEOMETRY FILE FORMATS:  see the file 'README.format'
---------------------


CREDITS
-------

Meshview 1.0-1.2 was written by Jeff (Hui) Ma and Konstantine Ishkov, and
designed by Andrew Hanson ([email protected]) with Jeff (Hui) Ma and
Konstantine Ishkov at the Computer Science Department, Indiana
University at Bloomington.  It is obtainable by anonymous ftp from
ftp.cs.indiana.edu:/pub/hanson/Meshview.x.tar.gz.


Any suggestions, comments, enhancements, and bug reports can be 
sent to the e-mail address above and will be greatly appreciated.


NOTES
-----

We acknowledge NCSA as the original source of several of the color
palettes included as examples with Meshview.