CPFG

Quick Contents

• Overview
• Display, Menu and Modes
• Documentation
• References
• Credits

Overview

The Continuous Parameter Fractal Generator (CPFG) is a program used for modelling objects using L-systems. Any object that can be described using fractals can be rendered, including plants, seashells and other naturally occuring objects and patterns. Figure 1, Figure 2 and Figure 3 below show some models rendered in CPFG. Models are defined by their data files, which in VLAB exist in a directory in the OOFS database. CPFG can be interfaced with the Panel Manager, so as a models parameters can be experimented with (refer to Panel Manager).

Display, Menu and Modes

CPFG renders 3-D images of models. The model can be viewed in 3-D space using the mouse, as shown in the following Table 1.

	Left button Rotate the object by clicking and dragging anywhere in the window. Rotation is about the center, in the direction of the mouse movement.
	Middle button Zoom In by clicking and dragging upwards in the window. Zoom Out by clicking and dragging downwards in the window.
	Right Button Activate the popup menu by pressing the right mouse button anywhere in the window.

Table 1 - CPFG mouse operations.

CPFG can also be used to run animations on models.
To change to Animate Mode, select Animate Mode from the popup menu.
To change back to Default Mode, select Don't Animate from the popup menu.

The Default Menu and the Animation Menu are shown in figures 4 and 5 below. Figure 6 shows intermediate stages in a sample animation sequence.

If an object's data files have been modified, either manually or using the Panel Manager, they must be reread by CPFG to reflect the changes. To reread all of the datafiles that define the object, select New Model from either popup menu.

File types used to define an object in CPFG include: L-System (*.l), View (*.v), and Animation (*.a).
Other datafiles that may be included are: materials (*.mat), surfaces (*.s), textures (*.rgb), and colourmaps (*.map).

Figure 6 - Three frames of a sample animation.

Documentation

CPFG is the most complex component of VLAB. The above documentation is far from complete, and provides only a basic description of what CPFG can do. For complete usage instructions, please refer to the following published documentation. Throughout the development of CPFG, much of the functionality, such as file formats and command line parameters, has remained consistent. This means that objects and their datafiles are platform and version independent.

Refer to CPFG Version 3.4 User Manual for documentation on CPFG usage.

For advanced graphics features, refer to Extensions of the graphical interpretation of L-systems based on turtle geometry.

A somewhat outdated tutorial, that may still be of some use, is also available, refer to Advanced Aspects of L-Systems.

References

Radomir Mech. CPFG Version 3.4 User's Manual. 1998

R. Mech, P. Prusinkiewicz, J. Hanan. Extensions of the graphical interpretation of L-systems based on turtle geometry. 1998

Catherine Jirasek. Advanced Aspects of L-Systems. 1997

Credits

L. Mercer, P. Prusinkiewicz, J. Hanan -the concept of the Virtual Laboratory and CPFG

Samantha Filkas - CPFG implementation vL1.0