L-studio editors Saving objects

Running a simulation

To perform a simulation of an L-system model, select Go! from the Cpfg or Lpfg menu. (Only one of these menus will be present, depending on whether the current object is a cpfg or lpfg object.) L-studio will then update all of the lab table files that are needed by the simulation program:

• the L-system file,
• the view file,
• the animation file,
• the color map or material file,

and, if present,

• surface files,
• contour files, and
• function files.

L-studio then runs the cpfg or lpfg simulation program.

Changing the model

After cpfg/lpfg has been launched, you may edit any components of the object (e.g. the L-system, view file, color map, etc.). To apply the changes to the simulator, you have two options:

• Select one of the New... commands from the Cpfg/Lpfg menu. Each of these options has a different effect:
  • New model saves all of the object's components, then makes the simulator reload them and rerun the entire simulation.
  • New L-system saves the L-system, then makes the simulator reload it and rerun the entire simulation.
  • New homomorphism saves the L-system, then makes the simulator reload it, but merely redraw the current string using the new homomorphisms. (For more on homomorphisms, see the Cpfg User's Manual.) This command is ignored by lpfg.
  • New view saves the view file, along with the colormap or material file, then makes the simulator reload them and redraw the current string using the new colors and view settings. Warning: the view file contains information about, among other things, the functions referred to by the L-system. If you change this information in the view file, New view will have it read in to the simulator, but it will not be used to regenerate the model. To do so, choose New model.
  • New projection saves the view file, then makes the simulator reload only those options which relate to the view projection.
  • New render saves the view file, then makes the simulator reload only those options which relate to rendering parameters.
  • New animate saves the animation file, then makes the simulator reload it and rerun the animation.

• Run L-studio in Continuous modeling mode. To activate this mode, select Continuous modeling from the Cpfg/Lpfg menu. In Continuous modeling mode, any changes you make to colors, materials, contours, surfaces, or functions, or any changes you make with a panel, are immediately applied to the cpfg/lpfg simulation. Whether the entire model is regenerated, or merely redrawn, depends on what is changed:

  Element modified	Effect on simulator
  L-system (via a panel)	Regenerates and redraws
  View (via a panel)	Redraws only
  Colormap	Redraws only
  Materials	Redraws only
  Surface	Redraws only
  Contour	Redraws only
  Function	Regenerates and redraws
  Other text file (via a panel)	Regenerates and redraws

  If you alter the L-system, view file, or other text file using the text editor, the changes will not automatically propagate to the simulator; you must use New....

Closing the simulator

cpfg/lpfg and the message log window will remain open until you either:

• close cpfg/lpfg explicitly,
• close the object in L-studio, or
• quit L-studio.

For detailed information on the use of cpfg see the Cpfg User's Manual. For detailed information on lpfg, see the Lpfg User's Manual.

The specifications file

Under vlab, the special file specifications is used to describe an object and all of the operations which can be performed on it. (See the vlab documentation.) L-studio performs the same function using file extensions; however, to maintain compatibility, L-studio is capable of running objects containing a specifications file. If the object contains such a file, L-studio tries to do the following:

1. Find a line that starts with letters cpfg. (These letters might be preceded by blank characters).
2. If the string cpfg is followed by some other characters (e.g. cpfg3.4) then the additional characters are skipped.
3. Check if the line contains -m or -M. If it doesn't then -m followed by the name of the colormap file present in the object is inserted. (Explanation: In the original SGI-IRIX version of cpfg, it is possible to instruct cpfg to use a colormap maintained by the windowing system, rather than by cpfg itself. This mechanism is not available in the Windows version, so cpfg must handle its own colormap.)
4. Call cpfg using this command line.

Important: this mechanism, while useful, might also cause some problems if the command line in the specifications file contains some UNIX-specific commands, such as calling more than one program (e.g. cpfg plant.l plant.v &; tail -F cpfg.out) or stream redirection (cpfg plant.l plant.v > dump.txt). L-studio passes the entire command line to cpfg, which will not start with incorrect parameters.

The LSspecifications file

The special file LSspecifications holds object-specific L-studio preferences. If there is an LSspecifications file present in the object, L-studio will look for a line which starts with the string "cpfg" or "lpfg". The text following this string is assumed to be the command line for the simulation program. The simulation program will be called with the parameters specified in this line. The menu label (Cpfg or Lpfg) shows which program was read from the LSspecifications when the object was loaded or the LSspecifications file was last saved.

If the object contains neither LSspecifications nor specifications files, or if one or both exist, but don't contain a line starting with "cpfg" or "lpfg", then the following algorithm is used to generate command line parameters for the simulation program:

The simulation program is assumed to be cpfg, with parameters

• -m color.map lsystem.l view.v anim.a in color map mode, or
• -M material.mat lsystem.l view.v anim.a in material mode.

If there is a *.e file in the object directory then the parameters will be:

• -e filename.e -m color.map lsystem.l view.v anim.a, or
• -e filename.e -M material.mat lsystem.l view.v anim.a.

A full description of cpfg's command line parameters is given in the Cpfg User's Manual.

When the cpfg/lpfg window has appeared, a log window appears immediately below it to display any messages the simulator generates.

L-studio components Saving objects