D3PLOT 22.1

General Graphics Problems

General graphics problems

The terminal won't draw anything

There are several possible causes. Have you:

  • BLANKED everything out of sight? Try turning the BLANKING switch off.
  • CLIPPED everything out of sight? Try turning the VOLUME_CLIPPING switch off.
  • Turned all entities off? Check the status of the ENTITY settings.
  • Scaled, rotated, zoomed everything out of sight? Try a ZERO command.
  • Are your deformations so large that the image at this complete state time is off the screen? Try an AC command.
  • Got a corrupt .PTF file? (Job crashed)

Facets of solids and thick-shells disappear when the model is very distorted

This is because the "back face" detection algorithm can get confused when elements become very misshapen, and removes faces that it shouldn't. Try turning the DISPLAY_OPTIONS , BACK_FACE switch on, which should cure the problem. Alternatively you can reduce distortions artificially by setting the displacement magnification factors to values less than 1.0: see DEFORM , MAGNIFY_DISPLACEMENTS .

2-D hidden-line removal seems to make mistakes

The default "painter" algorithm is cheap and cheerful, and it can make mistakes. You can prevent this by using the more expensive "rigorous" algorithm: see DISPLAY_OPTIONS , HIDDEN_LINE_OPTIONS .

Problems displaying stonewalls

Stonewalls, especially infinite ones, present a problem since their characteristic size is so much greater than typical facets in a model. This can show up very clearly in hidden-line plots where they often appear to be in front of or behind where they should be.

This is usually due to their interaction with the perspective calculation, and turning this off ( PERSPECTIVE , OFF ), and switching to "rigorous" hidden-line removal will improve matters considerably.


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