GLVis visualization tool
                                 version 3.0

                     _/_/_/  _/      _/      _/  _/
                  _/        _/      _/      _/        _/_/_/
                 _/  _/_/  _/      _/      _/  _/  _/_/
                _/    _/  _/        _/  _/    _/      _/_/
                 _/_/_/  _/_/_/_/    _/      _/  _/_/_/

                        http://glvis.googlecode.com

GLVis is an OpenGL tool for visualization of finite element meshes and
functions.

For building instructions, see the file INSTALL. Copyright information and
licensing restrictions can be found in the file COPYRIGHT.

When started without any options, glvis starts a server which waits for a socket
connections (on port 19916 by default) and visualizes any received data. This
way the results of simulations on a remote (parallel) machine can be visualized
on the local user desktop.

GLVis can also be used to visualize a mesh with or without a finite element
function (solution), as in 'glvis -m cube.mesh3d'. For parallel computations,
GLVis supports input from several parallel socket connections as well as the
visualization of parallel meshes and grid functions saved in separate files from
the command line as in 'glvis -np 4 -m mesh -g solution'. In both cases, it will
stitch the results to show the global mesh and solution. GLVis can also run a
batch sequence of commands (GLVis scripts), or display previously saved socket
streams. For a complete list of command line options, type 'glvis -h'.

Depending on the data type, variety of manipulations can be performed by using
the mouse and by typing (case sensitive) keystrokes in the GLVis window. Here is
a partial list of the available functionality. Some of these keys can also be
provided as input, using the '-k' command-line option and the 'keys' script
command.


Mouse functions
===============
Left       - Rotate the viewpoint
Middle     - Translate the viewpoint
Right      - Zoom in (up) / Zoom out (down)
Left+Shift - Start spinning the viewpoint (according to dragging vector)


Basic key commands
==================
h - Prints a short help message in the terminal

r - Reset the plot to 3D view
R - Cycle through the six 2D projections (camera looking in +/- x/y/z
    direction)
j - Turn on/off perspective
s - Turn on/off unit cube scaling

c - Display/Hide the colorbar
p - Cycle through color palettes (lots of options, use F6 for a menu)
t - Cycle materials and lights (5 states)
l - Turns on/off the light
g - Toggle background color (white -> black)

a - Toggle the bounding box axes
    The options are: -> none
                     -> bounding box with coordinates of the corners
                     -> bounding box without coordinates
                     -> red, green, blue colored main x, y, z axes; dashed box
m - Toggle the "mesh" state
    The options are: -> no mesh or level lines
                     -> draw the element edges (i.e. the mesh)
                     -> draw the level lines (use F5 to modify the level lines)
e - Toggle the "elements" state (see below for vector functions)
    The options are: -> show surface elements (corresponding to the function)
                     -> show no surface elements
                     -> show surface elements corresponding to det(J)
                     -> show surface elements corresponding to 1/det(J)

S - Take an image snapshot or record a movie (in spinning mode).
    By default, the screenshots are taken using the (external) command 'xwd'
    generating files with .xwd extension. When GLVis is compiled with libtiff
    support (see INSTALL) then the screenshots are taken internally and saved
    in TIFF format (.tif extension). In both cases, the generated image files
    can be easily converted to a more suitable format using e.g. ImageMagick's
    'convert' tool or the GIMP.
P - Print to a PostScript file (in non-texture mode)

q - Exit


Advanced key commands
=====================
f - Change the shading type (the way the elements and mesh are drawn)
    The options are: -> one triangle / quad per element with a constant normal
                     -> one triangle / quad per element with normals averaged
                        at the vertices
                     -> multiple triangles / quads per element, also allowing
                        for the visualization of discontinuous functions and
                        curvilinear elements (use i/I to control subdivisions)

i/I - Control element subdivisions
      there are two subdivision factors: -> element subdivision factor s1
                                         -> boundary subdivision factor s2
I - Cycle through the "subdivision functions", (prints a message in the
    terminal when changed)
    The options are: -> Increase subdivision factor:      s1 += s2
                     -> Decrease subdivision factor:      s1 -= s2
                     -> Increase bdr subdivision factor:  s2++
                     -> Decrease bdr subdivision factor:  s2--
i - perform the current "subdivision function"

A - Turn on/off the use of anti-aliasing/multi-sampling
b - Display/Hide the boundary in 2D scalar mode
L - Turn on/off logarithmic scale
\ - Set light source position (see Right+Shift)
* - Zoom in
/ - Zoom out
+ - Stretch in z-direction
- - Compress in z-direction
[ - Enlarge the bounding box (relative to the colorbar)
] - Shrink the bounding box (relative to the colorbar)
( - Shrink the visualization window
) - Enlarge the visualization window
. - Start/stop z-spinning (speed/direction can be controlled with '0'/'Enter')

w - Toggle clipping (cutting) plane in 2D (see also 'i' in 3D)
y/Y - Rotate clipping plane (theta) in 2D
z/Z - Translate clipping plane in 2D

` - Toggle a ruler, with initial origin at the center of the bounding box. The
    origin can be later moved with '~'.
    The options are: -> none
                     -> coordinate axes lines
                     -> coordinate axes planes
~ - Enter new ruler origin

k/K - Adjust the transparency level (works only when texture is off, see '!').
      The balance of transparency can be further adjusted with ',' and '<'.

! - Toggle the use of (1D) texture (smooth interpolation of colors)
    The options are: -> use discrete texture, the number of colors used depends
                        on the current palette
                     -> use smooth texture (interpolated from current palette)
                     -> do not use texture; colors are set at the vertices;
                        color interpolation may be bad

Ctrl+arrow keys - Translate the viewpoint

F3/F4 - Shrink/Zoom each element towards its center, to better visualize the
        different element shapes
F5 - Change the range and number of the level lines
F6 - Palette menu (negative repeat number flips the pallete)
F7 - Change the minimum and maximum values
F8      - List of material subdomains to show
F9/F10  - Walk through material subdomains
F11/F12 - Shrink/Zoom material subdomains (to the centers of the attributes)


Advanced mouse functions
========================
Middle+Ctrl       - Object translation (moves the camera left/right/up/down)
Middle+Ctrl+Shift - Object translation (turns the camera left/right/up/down)
Middle+Ctrl+Alt   - Moves the camera forward/backward (vertical mouse motion)
                    and tilts the camera left/right (horizontal mouse motion)
Right+Ctrl        - Object scaling (see also '[' and ']')
Left+Alt          - Tilt
Right+Shift       - Change light source position (see '\')


Vector data commands
====================
v - Toggle the "vector" state (uses vector subdivision factor, accept u/U)
    The options are: -> do not show vectors
                     -> show vectors as displacement
                     -> show vector field; vectors are uniformly scaled;
                        the color varies with the magnitude (or the current
                        "vector-to-scalar function", see keys u/U)
                     -> show vector field as above, but the vectors are scaled
                        proportionally to their magnitude
V - Change the scaling of the vectors relative to the default

d - Toggle the "displaced mesh" state: (see also keys 'n'/'b')
    The options are: -> do not show displaced mesh
                     -> show displaced mesh
                     -> assuming displacement field show deformation using
                        Cartesian lines
                     -> assuming displacement field show deformation using
                        polar lines
n - increase the displacement amount in 10% steps, wraps around from 100% to 0%
b - decrease the displacement amount in 10% steps, wraps around from 0% to 100%
B - Display/Hide the boundary in 2D vector mode

e - Toggle the "elements" state (vector data version)
    The options are: -> show surface elements corresponding to the current
                        "vector-to-scalar function"
                     -> do not show surface elements
                     -> assuming a displacement field show det(J)/det(J_d)
                     -> assuming a displacement field show det(J_d)/det(J)

u/U - Change the "vector-to-scalar function" and the vector subdivision factor
U - Toggle the functionality of 'u' (prints a message in the terminal when
    changed).
    The options are: -> Increase the vector subdivision factor
                     -> Decrease the vector subdivision factor
                     -> Cycle through "vector-to-scalar functions" choices:
                        -> magnitude:    sqrt(vx^2+vy^2)
                        -> direction from -pi to pi: atan2(vy,vx)
                        -> x-component:  vx
                        -> y-component:  vy
                        -> divergence:   div(v)
                        -> curl:         curl(v)  [skipped for H(div) elements]
                        -> anisotropy in grad(v)  [skipped for H(div) elements]

3D data commands
================
i   - Toggle clipping (cutting) plane
      The options are: -> none
                       -> cut through the elements
                       -> show only elements behind the clipping plane
x/X - Rotate clipping plane (phi)
y/Y - Rotate clipping plane (theta)
z/Z - Translate clipping plane
E   - Display/Hide the elements in the clipping plane
M   - Display/Hide the mesh in the clipping plane

o/O - Refine/de-refine elements (similar to 'i' in 2D)

u/U - Move level surface value up/down
v/V - Add/Delete a level surface value

w/W - Move boundary elements up/down in direction of the normal (i.e. "plot"
      the boundary values in normal direction)

F3/F4   - Shrink/Zoom boundary elements (to the centers of the attributes)
F8      - List of boundary subdomains to show
F9/F10  - Walk through boundary subdomains
F11/F12 - Shrink/Zoom material subdomains (to the centers of the attributes)


3D vector data commands
=======================
v - Toggle the "vector" state
    The options are: -> do not show vectors
                     -> show vectors as displacement
                     -> show vector field; vectors are uniformly scaled;
                        the color varies with the magnitude (or the current
                        "vector-to-scalar function", see key F)
                     -> show vector field as above, but the vectors are scaled
                        proportionally to their magnitude
                     -> show the subset of the vector field with scalar function
                        around a given value (adjusted with keys u/U and w/W)
                     -> show the vector field restricted to the boundary of the
                        domain
V - Cycle the "vector" state in the opposite direction of 'v'

u/U - Move the level field vectors (in the appropriate "vector" state)
w/W - Add/Delete level field vector (in the appropriate "vector" state)

d - Toggle the "displaced mesh" state: (see also keys 'n'/'b')
    The options are: -> do not show displaced mesh
                     -> show displaced mesh
n - increase the displacement amount in 10% steps, wraps around from 100% to 0%
b - decrease the displacement amount in 10% steps, wraps around from 0% to 100%

F - Change the "vector-to-scalar function"
    The options are: -> magnitude:   sqrt(vx^2+vy^2+vz^2)
                     -> x-component: vx
                     -> y-component: vy
                     -> z-component: vz