Field Precision title

Large mesh plots revisited: program-not-responding

Several users have reported intermittent plotting problems when working in Windows 7 with large meshes (i.e., millions of elements) in our 2D and 3D programs. I addressed the problem in a previous blog . In recent tests, I found that the precautions I described in the blog were necessary but not sufficient to ensure reliable plotting. This blog describes what I hope will be the final resolution.

The basic problem is that plotting a huge mesh is a big task, one that takes several seconds. Windows XP was a patient and well-adjusted operating system, so we never observed problems with large graphics tasks. In contrast, flashy Windows 7 always wants to show its speed and hates any operations that demand time. Our graphics programs create a memory bitmap and then flash it to the screen. For complex plots, the operations are intensive. There are two circumstances during bitmap generation where the plot may never appear:

  • The user changes the window focus (the issue discussed in the previous blog).
  • Windows 7 issues a Program not responding message.

Clearly, the solution to the second problem is to set Windows 7 so that it waits longer before sashaying off in a snit. Finding out how to do this is the real challenge. Windows Help offers no help, and Internet threads on the topic are generally diffuse. I offer the following procedure for our customers and as a general public service.

HOW TO MAKE WINDOWS 7 WAIT LONGER BEFORE ISSUING A PROGRAM-NOT-RESPONDING MESSAGE

  1. In the Start menu, pick Run.
  2. Enter regedit and run the program.
  3. Navigate to HKEY_CURRENT_USER/Desktop.
  4. Right-click on Desktop and choose New/String value.
  5. Fill in the name HungAppTimeout and press enter to create the entry.
  6. Right click on HungAppTimeout and choose Modify.
  7. Enter a number like 10000 for normal large meshes. Use a higher value if necessary.
  8. Exit regedit.

The new variable takes effect the next time you boot up. At this point, Field Precision programs should not cause the Program not responding message during bitmap regeneration. Large plots will be displayed as long as you have not changed the window focus.

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