visualpython-users

[Visualpython-users] smoother faster tube

[Bruce S. <bas...@un...>]

Attached is tube_smooth.py, which is significantly faster still, thanks to
being able to get attractive cylinders with only 25 sides (which is what I
found that Visual uses for cylinders) by smoothing the shading. The trick is
to choose normals not to the faces but to interpolate the normals between
adjacent faces.

Bruce Sherwood

[Visualpython-users] pixel plotting

[Gregor L. <gl...@ao...>]

I've forwarded this message of LANEY MILLS originally sent
to tu...@py....
Laney, if you are using vpython heavily, have a look at this list!

vis...@li...

The vpython library has wonderful plotting routines.  One of them is gdots. 
 Gdots plots points on a graph.  Although one can control the color of the 
dots, one apparently cannot control the size of the dots.

Suppose I wanted to write  Python program to create the Mandelbrot set, 
which has hundreds of thousands of dots.  One needs to plot individual 
pixels.

Here are my two questions then:

Is there a formal description of the various vpython routines?  There is a 
wonderful tutor, but no formal description with list all the attributes 
ascribable to gdots.

If gdots can't be made to plot individuals at a given (x,y) point, is there 
some other way to do it?

Thanks


Laney Mills

Re: [Visualpython-users] pixel plotting

[Bruce S. <bas...@un...>]

There are no pixel-oriented options in VPython. The only thing you could do
to paint a dot-oriented picture would be to use tiny boxes (or better,
faces) that tile the space.

The gdots option on the graph plot is a kludge which uses the letter "o"
from a font (and as a result doesn't work properly on all platforms). The
reason for this kludge is the need for plotting a small circle on a graph
whose x and y axes may differ enormously (so that a ring object for example
would display as an ellipse).

There is no formal description of VPython routines, but the online reference
manual does attempt to list all attributes of VPython objects. An exception
is the graphing routine, which probably should list all of the attributes of
a graph object, since occasionally it is useful to refer directly to some of
the VPython objects that graph.py uses. You might like to just look at
graph.py to see what's there. However, this isn't a useful place to find
something for pixel plotting.

Bruce Sherwood

----- Original Message -----
From: "Gregor Lingl" <gl...@ao...>
To: "vpusers" <vis...@li...>
Cc: <mi...@co...>
Sent: Sunday, August 11, 2002 2:07 PM
Subject: [Visualpython-users] pixel plotting


> I've forwarded this message of LANEY MILLS originally sent
> to tu...@py....
> Laney, if you are using vpython heavily, have a look at this list!
>
> vis...@li...
>
> The vpython library has wonderful plotting routines.  One of them is
gdots.
>  Gdots plots points on a graph.  Although one can control the color of the
> dots, one apparently cannot control the size of the dots.
>
> Suppose I wanted to write  Python program to create the Mandelbrot set,
> which has hundreds of thousands of dots.  One needs to plot individual
> pixels.
>
> Here are my two questions then:
>
> Is there a formal description of the various vpython routines?  There is a
> wonderful tutor, but no formal description with list all the attributes
> ascribable to gdots.
>
> If gdots can't be made to plot individuals at a given (x,y) point, is
there
> some other way to do it?
>
> Thanks
>
> Laney Mills

RE: [Visualpython-users] pixel plotting

[David S. <dsc...@vi...>]

Just in case anyone is interested in extending VPython to make it more
useful for drawing things such as Mandelbrot sets, I will suggest that
it might be more useful to add texture support (for example, a textured
plane object) than to add a point() or points() primitive.  VPython's
coordinate system and some lower level details will make it awkward to
draw an image on the screen using points (quite apart from the
performance issues).

For example:

p = plane( texture = array( (500,500,3), Float ) )

for x in range(500):
  for y in range(500):
    p.texture[x,y,:] = mandelbrot(x,y)

The coordinate system issue would still have to be addressed if you want
exact pixel results.

Dave

> -----Original Message-----
> From: vis...@li... 
> [mailto:vis...@li...] On 
> Behalf Of Bruce Sherwood
> Sent: Sunday, August 11, 2002 2:27 PM
> To: vpusers
> Cc: mi...@co...
> Subject: Re: [Visualpython-users] pixel plotting
> 
> 
> There are no pixel-oriented options in VPython. The only 
> thing you could do to paint a dot-oriented picture would be 
> to use tiny boxes (or better,
> faces) that tile the space.
> 
> The gdots option on the graph plot is a kludge which uses the 
> letter "o" from a font (and as a result doesn't work properly 
> on all platforms). The reason for this kludge is the need for 
> plotting a small circle on a graph whose x and y axes may 
> differ enormously (so that a ring object for example would 
> display as an ellipse).
> 
> There is no formal description of VPython routines, but the 
> online reference manual does attempt to list all attributes 
> of VPython objects. An exception is the graphing routine, 
> which probably should list all of the attributes of a graph 
> object, since occasionally it is useful to refer directly to 
> some of the VPython objects that graph.py uses. You might 
> like to just look at graph.py to see what's there. However, 
> this isn't a useful place to find something for pixel plotting.
> 
> Bruce Sherwood
> 
> ----- Original Message -----
> From: "Gregor Lingl" <gl...@ao...>
> To: "vpusers" <vis...@li...>
> Cc: <mi...@co...>
> Sent: Sunday, August 11, 2002 2:07 PM
> Subject: [Visualpython-users] pixel plotting
> 
> 
> > I've forwarded this message of LANEY MILLS originally sent
> > to tu...@py....
> > Laney, if you are using vpython heavily, have a look at this list!
> >
> > vis...@li...
> >
> > The vpython library has wonderful plotting routines.  One of them is
> gdots.
> >  Gdots plots points on a graph.  Although one can control 
> the color of 
> > the dots, one apparently cannot control the size of the dots.
> >
> > Suppose I wanted to write  Python program to create the Mandelbrot 
> > set, which has hundreds of thousands of dots.  One needs to plot 
> > individual pixels.
> >
> > Here are my two questions then:
> >
> > Is there a formal description of the various vpython 
> routines?  There 
> > is a wonderful tutor, but no formal description with list all the 
> > attributes ascribable to gdots.
> >
> > If gdots can't be made to plot individuals at a given (x,y) 
> point, is
> there
> > some other way to do it?
> >
> > Thanks
> >
> > Laney Mills
> 
> 
> 
> 
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