WHAT IS VRENG ?
---------------
VREng (Virtual Reality Engine) is a distributed 3D application
allowing navigation in virtual worlds connected over the Internet
using IP Multicast Technology.


PREREQUISITS
------------
Your machine and your network must support IP Multicast, mainly IGMP.
You need the X-Window System (X11R5 or X11R6 or Openwin).
Your screen must have a color depth of 8 or 16 or 24.

Eventually you need the classical MBone tools like vat, vic and wb
which are used by VREng as external applications and Netscape or mMosaic.

To improve performances VREng uses threads library POSIX compatible,
if your system supports this feature use configure with the --enable-thread
option.


SUPPORTED PLATFORMS
-------------------
	- solaris2.x
	- sunos4.1.x
	- hp-uxB.10.20
	- linux-i86
	- linux-sparc
	- freebsd[345].x
	- netbsd1.2-sparc

VREng has not been ported on other platforms yet, but any
port will be welcome.


DOWNLOADING
-----------
The VREng sources are available at:
	ftp://ftp.enst.fr/pub/mbone/vreng/vreng.tar.gz
The Ubit Toolkit sources are available at:
	ftp://ftp.enst.fr/pub/unix/gui/ubit/ubit.tar.gz
The TinyGL Library sources are available at:
	ftp://ftp.enst.fr/pub/mbone/vreng/TinyGL.tar.gz


COMPILING
---------

VREng uses an OpenGL library. The configure script will usually figure out
which one is installed on your system. There are basically three possibilities:

1 - Your system already has a vendor OpenGL library installed or available at:
	http://www.sun.com/opengl/
    don't forget to retrieve patches for X11 server and accelerate cards.

2 - You want to use the Mesa free OpenGL emulation library.
    You can retrieve the last stable release at:
	http://www.mesa3d.org/

3 - You want to use TinyGL, which is a fast but incomplete emulation of OpenGL
    You can get it at:
	http://www.enst.fr/~bellard/TinyGL.html

If your OpenGL library is not visible through the standard paths, you
can use the configure option: --with-GL-prefix=DIR. DIR must be an
absolute path. Type 'configure --help' to have more options.

VREng can work with 3 different GUI (X11 Athena, Motif, Ubit).
The Glut and Tcl/Tk toolkits are no longer supported.
The default is Ubit, therefore you can use X11-Athena or Motif, but
the main support and the new VREng features are only supported with Ubit.
Ubit is a new Toolkit we have developed at ENST, you can get it at:
	ftp://ftp.enst.fr/pub/unix/gui/ubit/ubit.tar.gz
	http://www.infres.enst.fr/~elc/

We *strongly* recommend to use the Ubit Toolkit to benefit from
last developments.

The configure features --with-motif, --with-athena
can be used to choose another GUI than Ubit (the default).

Before compiling VREng check available features with:
	./configure --help

To optimize the code you can add --enable-optimize option.
If you have X11 headers buggy, you can use the --enable-permissive option.
If your system doesn't support Posix Threads, use --disable-pthread.
If your machine support 64 bits words, you can try the --enable-64bit option.

In general, to compile VREng with defaults, type:
	./configure

either use the pre-configurated shell-scripts:
	configure-ubit-opengl	(Ubit & OpenGL)
	configure-ubit-mesa3d	(Ubit & Mesa3D)
	configure-ubit-tinygl	(Ubit & TinyGL)
	configure-motif-opengl	(Motif & OpenGL|Mesa3D)
	configure-athena-mesa3d	(X11-Athena & Mesa3D)
	...

we strongly recommend to use:
	configure-ubit-opengl or configure-ubit-mesa3d

and then
	gmake or make


INSTALLING
----------
The vreng-{ogl,mgl,tgl} binary executable and the vreng script-shell
will be installed by default in /usr/local/bin.
To do this, type:
	make install
or
	make install-strip

You must also install the sdr plugin in your ~/.sdr/plugins directory


CONFIGURING
-----------
After installing the sdr plugin, you can use sdr to launch vreng
clicking on the media "games".
Vreng will retreive automatically world description by http from the URL:
http://www.infres.enst.fr/net/vreng/vre/

To add your pictural representation, build a gif of your face
of size 256x256 pixel (using xv), put it into the directory

	~/public.html/vreng/yourfrontface.gif

and update your ~/.vreng/prefs to adjust your preferences:

	mapface http://www.yoursite/~yourlogin/vreng/yourfrontbody.gif
	mabback http://www.yoursite/~yourlogin/vreng/yourbackbody.gif

See the file conf/prefs in this distribution.



HOW TO NAVIGATE ?
-----------------
Use the arrow keys on your keyboard. There are 6 spatial degrees of freedom:
	- key_up to go straight on
	- key_down to move back
	- key_right to turn on your right
	- key_left to turn on your left
	- key_pageup to look up
	- key_pagedown to look down
plus
	- key_home to look forward
	- key_end to accelerate
	- key_insert to rise up
	- key_delete to land on the ground

To identify objects, click on the button1 of the mouse, the name
of the pointed object will appear, maybe with a pushdown menu containing buttons
to activate an action on this object (for example open/close for a door).


DOCUMENTATION
-------------
The documentation is not any longer in this distribution.
See http://www.infres.enst.fr/net/vreng/html/ for more details.


AUTHORS
-------
Denis Arnaud <denis.arnaud@free.fr>: interface between world mgt and network
Fabrice Bellard <bellard@email.enst.fr>: 3D rendering
Stephane Belmon <belmon@email.enst.fr>: network interface
Samuel Orzan <orzan@email.enst.fr>: world management
Lionel Ulmer <ulmer@email.enst.fr>: the GUI under X11
Philippe Dax <dax@enst.fr>: project supervisor

CONTRIBUTORS
------------
Francois Karr <karr@email.enst.fr>: Windows95 port
Vincent Haverlant <haverlan@aist.enst.fr>: RTP mechanisms
Adrien Felon <felon@inf.enst.fr>: AOI objects and Tcl/Tk GUI
Eric Lecolinet <elc@enst.fr>: new GUI + Ubit GUI
Patrick Bellot <bellot@enst.fr>: languages VREL, VREML and editors

MAINTAINER
----------
Philippe Dax <dax@enst.fr>: project supervisor

CONTACTS
--------
The mailing-list <vreng@inf.enst.fr> has been opened for any discussion
about the VREng application and its evolution. To be added on this
mailing-list, send a message to <vreng-request@inf.enst.fr>.

You can send BUG reports and comments at <vreng@inf.enst.fr>.

Have fun!

-- Philippe Dax -- <dax@inf.enst.fr>
