[ANNOUNCE] A Virtual Reality

Linas Vepstas (linas@innerdoor.austin.ibm.com)
Mon, 24 Oct 1994 17:53:45 -0500

This came across the YART mailing list; thought I'd
cc this mailing list.

>Date: Mon, 24 Oct 94 18:03:14 +0100
>From: Ekkehard.Beier@Prakinf.TU-Ilmenau.DE (Ekkehard Beier)
>To: yart@metallica
>Sender: Ekkehard.Beier@Prakinf.TU-Ilmenau.DE
>Subject: [ANNOUNCE] A Virtual Reality application
>YART/VR 1.1 allows you moving around in virtual scenes
>across the net and meeting other people.
>It is based on following public domain software:
>- Tcl7.3 - an extensible interpreter language
>- Tk3.6 - an X11 widget set based on Tcl
>- YART1.1 - a general-purpose 3D graphics kernel
>- IOM1.1 - Tk based tools for programming YART
>The whole stuff is based on two metaphores: The SCENE and the USER.
>A SCENE is a kind of a server running anywhere in the net and
>can be addressed via <scene_name>@<host_name>, e.g.
>"castle@" [BTW, you will not reach this host.]
>A physical USER is represented by an object of a Tcl class
>that can be specified freely by the user. The representation
>bases on YART graphical primitives like Sphere, Block, Cylinder,
>Quadmesh, Polygon, Polyhedron, Text and so on. Additionally,
>methods can be provided for this class like "-sitDown" or "-smile"
>or what ever.
>User commands are:
>- login/logout
>- move forward(backward) by a specified distance in view direction
>- move upward(downward) by a specified distance
>- rotate left/right by a specified angle
>- send a pick ray into the scene
>- broadcast a message to all users
>- call a method of your representation
>User commands will be send to the scene and the scene sends resulting
>commands back. Thus the scene can prevent you from going thru a wall,
>for instance.
>Two executables are provided, when YART/VR has been installed.
>These are standard tools and can be replaced by other ones.
>"vr_user" is a Tk based front end that provides mouse-driven
>interactions for moving in the scene, scales for camera parameters
>and text input/output. It looks for your representation file
>"vr_scene" has to be started with one argument - the name of the
>scene. Then it tries to read $HOME/.scenes/<the name>.scn
>Scene files are in principle standard YART metafiles, additionally
>you can specify the initial position and angle of a user that
>comes into the scene and the maximal number of users in the scene.
>The semantics of a pick in this scene is as follows:
>If you hit a user you'll get the name of the user and the picked
>user will be informed that you picked him.
>The current implementation of scene-user communication is based on
>internet domain sockets.
>- user (front ends): - stereo output for SGI machines (a YART interface
> to SGI stereo hardware is part of the YART distribution)
> - textual control of movement,
> - radiosity and ray-tracing images of the scene (this is easyly
> possible by switching the camera into an another mode)
> - spaceball integration (YART provides spaceball events for that)
>- scene:
> - the complete semantics of user motion and picking is controlled
> by the scene, thus you can add any specific behavior in
> subclassed scenes
> - handling of subscenes to reduce rendering time
>- communication:
> - the current socket/XDR stream based communication is nothing else
> than a subclassed realization of the abstract communication
> classes. Thus you may add other realizations (e.g. usage of
> shared memory in local connections) for future versions.
> - there is only one scene at one host allowed at one time
> - the scene interpreter is hidden from the outside by a communi-
> cation interpreter. All accesses (with exception of login) must
> provide a multi-digit user id.
>via ftp anonymous from metallica.prakinf.tu-ilmenau.de [],
>directory pub/PROJECTS/GOOD1.10/yartvr1.10.tar.gz. First read README.GOO
>and install the other stuff, then read INSTALL.YVR.
>- graphics: X11 with special support of IRIS GL, OpenGL, IBM GL, VOGL
>- netstuff: BSD compatible (internet domain sockets)
>- WWW: http://metallica.prakinf.tu-ilmenau.de/YARTVR.html
>- mailling list: yart@prakinf.tu-ilmenau.de
> [send mail with subject "subscribe YART mailing list"
> to ekki@prakinf.tu-ilmenau.de ]
>Good luck and see you in "byEkkiAtWork@dali.rz.tu-ilmenau.de"
> Ekki.
>Thanks goes to Jochen Pohl (pohl@rz.tu-ilmenau.de) for help with XDR stream.
>* Ekkehard 'Ekki' Beier *
>* email: ekki@prakinf.tu-ilmenau.de *
>* phone: ++49-3677-691243 fax: ++49-3677-691201 *
>* talk : ekki@metallica.prakinf.tu-ilmenau.de [] *
>* www : http://metallica.prakinf.tu-ilmenau.de/ekki.html *
>* Technical University of Ilmenau *
>* Department of Computer Graphics *
>* Am Ehrenberg, PSF 327, D-98684 Ilmenau, GERMANY *