ABOUT
================================================================================
ptsviewer is a simple OpenGL based viewer for point clouds stored as pts or ply
file. In Ply files the either the element “vertex” or the element “point” is
loaded as point cloud data. If both elements are present, the “point” element
data is preferred.  Both colored and non colored point clouds are supported.
Multiple clouds can be loaded and pose estimations for matching can be created.


PTS FILE FORMAT
================================================================================
The pts file format is designed to store point clouds in a simple, human
readable way. Each point is stored as a couple of values in one line of the pts
file. One line contains at least three values, representing the x-, y- and
z-position of the point in a three-dimensional cartesian coordinate system. If
one line has six or more values, it is assumed that the last three values
represent color information as 8-bit vales in a rgb color space. Additional
information (like remission values, accuracy, ...) may be stored between these
to sets of values. They are ignored.

Example of a pts file containing values for position, color and accuracy:

...
-101.132004  -16.282200   -1.671650    9672.242188  88  69  60
 -97.345001  -23.159800   -1.601770    9324.614258  88  69  60
 -96.522903    5.354720   -3.460280    9934.269531  86  69  63
 -96.475403    5.382280   -1.612710    9622.832031  86  69  63
 -95.455399    5.657920   -3.712910    9886.268555  86  69  63
...


REQUIRED LIBRARIES
================================================================================

 + OpenGL
 + The OpenGL utility toolkit
 + The OpenGL utility library
 + librply
    - https://github.com/lkiesow/librply


Installation on Ubuntu:
> apt-get install freeglut3 freeglut3-dev

Installation on Fedora:
> yum install freeglut freeglut-devel


COMPILATION / INSTALLATION
================================================================================

Edit config.mk (probably no changes have to be made) and call for compilation:

> make

If you want not only compile it, but install it just call with the appropriate
rights:

> make clean install

CONTROLS
================================================================================

For more details have a look at the manpage for ptsviewer.

-- Mouse: ---
 drag left   Rotate point cloud
 drag right  Move up/down, left/right
 wheel       Move forward, backward (fact)
-- Keyboard (normal mode): ---
 i,o,p       Increase, reset, decrease point size
 a,d         Move left, right (fast)
 w,s         Move forward, backward (fast)
 q,e         Move up, down (fast)
 A,D         Move left, right (slow)
 W,S         Move forward, backward (slow)
 Q,E         Move up, down (slow)
 j           Jump to start position
 f           Flip point cloud
 y,x         Invert rotation
 +,-         Zoom in, out
 *,/         Increase/Decrease movement speed
 0...9       Toggle visibility of point clouds 0 to 9
 t           Toggle visibility of all point clouds
 u           Deselect all clouds
 c           Invert background color
 <return>    Enter selection mode
 m           Enter move mode
 <esc>       Quit
-- Keyboard (selection mode): ---
 0..9        Enter cloud number
 <return>    Apply selection.
 <esc>       Cancel selection
-- Keyboard (move mode): ---
 a,d         Move left, right (fast)
 w,s         Move forward, backward (fast)
 q,e         Move up, down (fast)
 A,D         Move left, right (slow)
 W,S         Move forward, backward (slow)
 Q,E         Move up, down (slow)
 r,f         Rotate around x-axis
 t,g         Rotate around y-axis
 z,h         Rotate around z-axis
 R,F         Rotate around x-axis (slow)
 T,G         Rotate around y-axis (slow)
 Z,H         Rotate around z-axis (slow)
 p           Print pose
 P           Generate pose files in current directory
 m,<esc>     Leave move mode