Project "Apval"

Project "Apval" ( "smooth" in Lithuanian) was created as my Bachelor Informatics thesis "Smoothing of polyhedral surfaces by «Butterfly» method" (also used a modified «Butterfly» method).

The program allows:

    • Reads VRML file and loads its three-dimensional vector shapes consisting of triangles and write (modified) data back to the same file;
    • The program allows to view the three-dimensional vector shapes in wireframe mode in the four different views (with zoom and panning);
    • User can choose the edges of shapes for a smoothing in several ways: all, none, some, some external edges;
    • User can produce smoothing of chosen edges;
    • User can go back to previous states, or to modified states (forward).

The program main window (with the "pyramid" figure):

The following shows the smoothing of the "pyramid" figure four times:

The following shows the four smoothing steps of the figure consisting of a single triangle (the extreme edges are not marked by a heavy lines):

How to set smoothing:

Select the figure and its edges to smooth: all, none, some edges, some of the external edges (if any).

A list of external edges of the selected figure; edges going to smooth are marked.

Searching and selecting for the chosen figure edges for a smoothing:

1. Select the first point;

2. Select the second point from the list of points connected to the first selected point via edge.

For the convenience of the user in selecting the figures, it stands out in black (gray) color on all screens.

Also highlighted selected points (filled squares).

The edges wich are marked for smoothing colored black, are not marked - gray.

Additional options to select and visualize the external edges are made because if not all the edges are smoothed, but the only external, then are achieved a great savings time, with the same appearance of the edge of the figure:

View of figure's part after the 7 smoothing (dividing all the edges). Smoothing took 130 seconds*

View of figure after the 6 smoothing (dividing all the edges). Smoothing took 9 seconds*

The initial appearance of the object

View of figure after the 6 smoothing (dividing only external edges). Smoothing took 1 second*

View of figure's part after the 7 smoothing (dividing only external edges). Smoothing took 1 second*

* Note: performing computer 2002-nd year.

A sample scene, to work with which this program was created (different colors denote different objects, the external edges are marked thicker):

A program creation time: the "core" - 2 weeks; graphical version of the program - 4 weeks.