SPACE

HOWTO

                    VIEW3D HOWTO
                    ============


Introduction
============

This file describes how to create 3d scene files using Space and how to
view them.


Creating scene files
====================

To create a scene file, use the '-s' option of Space. For example:

   % space3d -C3 -s inv.scn inv

This creates a scene file for the cell `inv'. The scene will contain drawing
primitives describing the extraction process. For example, the `tiles'
encountered during extraction are represented in the scene file (tiles are
triangular or quadrilateral elements describing areas with the same mask).
Also, because we used the -3 and -C option, so called spider elements are
written to the scene, which describe the finite elements used for 3d
capacitance extraction.

In Space, you can specify additional parameters by using the '-P' option,
or the '-S' option, see space (1ICD) for details. The part of space that
generates scene files recognizes parameters that start with the qualifier
"scene". You can specify exactly what should be drawn by putting the
following block in a parameter file, and by editing the values (the values
shown here are the default).

   scene.show_spider on
   scene.show_green off
   scene.show_tile on
   scene.show_text on

Note that the `show_green' option will show all capacitive interaction taken
into account by Space; turning this option on will result in very large
scene files, which take a large of time to process, so you are advised to
only use this option for small cells. The default for this option is `off'.


Viewing scene files
===================

You may use the `view3d' command to view a generated scene file. The tool is
invoked as follows:

   % view3d inv.scn

NOTE: In order to run view3d, you need to have the GLX extension installed
on your X server. If you don't have this extension installed, please contact
your system administrator. (A small how-to for installing this extension is
provided below).

Initially, all the types of generated drawing objects are shown, which may
make the overall picture somewhat messy. You can turn off certain object
types by opening the options dialog box, under the menu "Edit | Options".
In this dialog box, you can also specify some other preferences, e.g. that
some objects are to be drawn as wire-frame instead of as a solid model.

Each object (= drawing primitive) comes with a so called time code.
This is simply a number with which we can sort the objects in time.
You can specify the time code at which you would like to view the scene
in the options dialog box, under the "Time Codes" tab.


Enabling the GLX module on your X server (Linux only)
=====================================================

This section describes how you can enable the GLX module on your X server.
This manual applies to Linux (XFree86) only.

First, make sure that you have a file named "libglx.a" in the directory
/usr/X11R6/lib/modules (or in one of the subdirectories there). If not,
you probably have an old version of XFree86, and you probably will not be
able to use a GLX extension.

Then, make sure that the following lines (or equivalent) are in your
XF86Config file:

   Section "Module"
       Load "glx"
   EndSection

(If there already is a "Module" section in your XF86Config file, then you
only need to add the Load statement, of course). You can usually find the
XF86Config file in /etc/X11, or somewhere in /usr/X11R6/lib.

Finally, restart your X server, and watch the output to see if X is using
the proper XF86Config file, and to see whether the glx module could be
loaded. You can also use the command:

   % X :1

to start a second X server on your machine. You can usually switch between
X servers using the key combinations ALT+F7 and ALT+F8.