AutoCAD, X11, and graphics

Visitor # 7668 since 14.SEP.2003


X Windows Resources for AutoCAD:

AutoCAD uses a text file, the display resources file, specified by the ACADRESFILE environment variable, to store X11 resource names and values. By default, the display resources file is .Xdefaults in the user's home directory. Resource names are similar to environment variables. AutoCAD reads them and uses their values to set the display. AutoCAD uses the resource names in the following tables. Please be advised that resource names are both case sensitive and must be spelled exactly. In light of this, cutting and pasting is HIGHLY recommended!

Resource Format Default Driver
AutoCAD-Graph.geometry: WxH+x+y 800x650+0+50 All
AutoCAD-Text.geometry: WxH+x+y 800x650+20+70 All
AutoCAD-Render.geometry: WxH+x+y 800x650+20+100 All
AutoCAD-Graph*fontList: string fixed All
AutoCAD-Text*fontList: string fixed All
AutoCAD-Graph*foreground: string white All
AutoCAD-Graph*background: string current All
AutoCAD-Graph*Drawing*background: string black Motif
AutoCAD-Graph*Drawing*foreground: string white Motif
AutoCAD-Text*foreground: string white All
AutoCAD-Text*background: string current All
AutoCAD-Graph.scrollLines: integer 32 All
AutoCAD-Text.scrollLines: integer 512 All
AutoCAD-Graph*doubleClickInterval: integer 500 Motif
AutoCAD-Graph*useMenuBar: true/false true All
AutoCAD-Graph.useSideMenu: true/false false All
AutoCAD-Graph.useCommandArea: true/false false All
AutoCAD-Graph.usePrivateColormap: true/false false Motif
AutoCAD.useToolBar: true/false true All
AutoCAD-Graph.gamma: true/false false Motif
AutoCAD.useStatusBar: true/false true All
AutoCAD.commandLines: integer 3 All
Table: X Windows Resources

To avoid interactions with other applications, it is best to place AutoCAD's X resources in a separate file, rather in the global ~/.Xdefaults file. By using the ACADRESFILE environment variable, you can easily do this. I place my X resources in a file called Acadr13 and place it in my ACADCFG directory and set the ACADRESFILE variable as follows:

csh> setenv ACADRESFILE "$ACADCFG/Acadr13"
- or -
sh/ksh> export ACADRESFILE="$ACADCFG/Acadr13"

You can also place system default settings in a file named:


If you choose this method the order of precedence is as follows:

  1. Internal AutoCAD default values
  2. /usr/lib/X11/app-defaults/AutoCAD (if it exists)
  3. $ACADRESFILE (if it exists)
  4. Otherwise ~/.Xdefaults (if it exists and has AutoCAD* settings)

Feel free to experiment with the settings in this file to adjust AutoCAD's appearance and behavior to your liking.

Hint: you can set the window geometry by placing and sizing the AutoCAD windows as desired then use the AutoCAD command _CONFIG and select the "Configure System Console" option to save the current window positions and sizes.
Note: Most of the resource names have changed between R12 and R13.

One further word of advice is that certain resources, such as AutoCAD-Graph.useSideMenu: for example, are duplicated in the AutoCAD display configuration (i.e. "Do you want a screen menu?"). That is, the X resource controls whether the side menu is expressed in Motif (3D style buttons) or not. The AutoCAD display configuration controls whether the side menu is displayed or not. However, the X resource overrides the AutoCAD setting, so the logic is as follows:

Side Menu Type: useSideMenu:true useSideMenu:false
screen_menu=Y Motif X11 or GL
screen_menu=N Motif none
Table: Side Menu Logic

Similar logic applies to the Command Prompt Area and the the pull-down Menu Bar configurations.

Backing Store:

Backing store is a feature of SGI's X server that is used by the X/Motif display driver to repair window damage caused by dismissing dialog boxes and other actions. If you run the X/Motif display driver for AutoCAD, you'll need to turn Backing Store on. This can be accomplished by editing the X Display Manager (xdm) configuration file:


to read:

:0 secure /usr/bin/X11/X -nobitscale -c -pseudomap 4sight -solidroot sgilightblue -cursorFG red -cursorBG white

Note: the default option "-bs" has been removed.

After rebooting your workstation, backing store will be enabled. However, you should be aware that backing store can cause increased memory use and slow graphics performance. In effect backing store functions by drawing into off-screen memory when portions of windows are obscured. When the obscured portion of the window is later exposed, the off-screen image is copied back to repair the damaged area. In order for backing store to work, all windows on the screen must be saved and this at a memory cost of 32-bits (4-bytes) per pixel. You can see how this can add up quickly. Also you may find certain programs that do not operate properly with backing store enabled. If you would prefer to run AutoCAD without backing store, you should install and use the GL display driver.

One tip I like to recommend, especially if backing store is enabled, is to change the default setting of the X display Manager (xdm) in order to restart the Xserver every time you log out. This way, any extra memory consumed with backing store is automatically returned to the operating system. To do this, simply edit the following file (as root):


and change the line that says:

  DisplayManager._0.terminateServer:   False

to read

 DisplayManager._0.terminateServer:    True

Now, every time you log out and back in, you'll have a brand new Xserver running.


O² and Octane:

AutoCAD R13_c4 runs very nicely on the new workstations and operating systems. In general, AutoCAD will benefit from systems that include secondary cache support (be sure you order the SC CPU version, not the PC). The increased memory bandwidth of the new Unified Memory Architecture greatly benefits operations on large drawing files as does the new Ultra SCSI disk interfaces and XFS file systems.





AutoCAD on High-End Graphics Systems:

The default X/Motif display driver shipped with all versions of AutoCAD may not function on certain high-end SGI graphics systems; including the Reality Engine; and on all SGI systems running a 24-bit default X server. You'll probably encounter an error message similar to:

rcacadmx: ....
FATAL ERROR: No display driver

The GL driver for AutoCAD has been designed to work around these problems. In order to reconfigure AutoCAD to run the GL driver, you'll need to do the following:

acadr13 -r
Select the GL display driver and exit AutoCAD.
Note: Setting ACADDISPLAY to NULL forces AutoCAD to use the null display driver instead of the Motif display driver.


Overlay Drawing Problem:

Aside from the above, certain other high-end graphics systems may exhibit a problem displaying certain user-interface components with the GL Display Driver; namely the Real-Time Birdseye View, floating Command Palette, or any other component which is drawn in the overlay bitplanes. Systems exhibiting this problem include Indigo2-Impact and O2. The problem arises from a conflict between the IrisGL graphics library on the Impact and O2 and the IrisGL Display Driver. It is anticipated that an OpenGL display driver will be available shortly to address this issue and to provide increased performance.


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[Last updated: 25.December.2014]