Now available at http://sourceforge.net/projects/visualpython for
Windows and Linux/Unix:
Improvements to scene viewing and autoscaling, including hysteresis that
prevents fibrillation, where the camera jitters in and out. Everywhere
you can now use "opacity" instead of "alpha". Graph and stonehenge now
work. Labels still problematic on Windows. Also still true that rings
have fixed radius and setting axis other than in x direction makes mouse
coordinates wrong. Arrows still get picked by mousing far from the arrow.
The hysteresis feature can be seen by running the example program
bounce.py. It used to be that the camera zoomed in and out as the ball
bounced up and down, but now the camera stays rock steady. The scheme is
basically this: If the scene grows, move the camera back to include the
larger scene (unless the scene is merely growing back to a previous
size). But if the scene shrinks somewhat, don't move the camera in,
unless the scene shrinks drastically as can happen when you're first
assembling a scene.
The opacity vs. alpha issue is this: It has always been true that this
property was called "opacity" in labels. In the computer graphics
community it is often called "alpha", but not always. For example, in
Photoshop the term "alpha" is used with many different kinds of
graphics-associated channels, not just opacity.
In 4.beta4, you can still use alpha as a synonym for opacity, but the
documentation (when written) will emphasize opacity.
Bruce Sherwood
|
