Re: [Visualpython-users] Major Problems with Latest Windows Release of VPython

I installed the latest VPython for Windows (prints 2003-03-15 when you run),
and I can't reproduce any of these problems. All the demos and test routines
run fine. This is on Windows 2000.

At first your very last test showed nothing, but that was simply because
there was a typo in your faces position list:

VertexList = [(0,0,0),(1,0,0),(1,0,0)]
should be
VertexList = [(0,0,0),(1,0,0),(1,1,0)]

Unless you've already tried it, the first thing to do might be to uninstall
Visual (and maybe even Python) and reinstall. It sounds like something is
corrupted on your machine, or in the download.

Bruce Sherwood

----- Original Message -----
From: "IVES,THOM (HP-Boise,ex1)" <tho...@hp...>
To: "Visual Python Users (E-mail)"
<vis...@li...>
Sent: Wednesday, April 23, 2003 3:46 PM
Subject: [Visualpython-users] Major Problems with Latest Windows Release of
VPython


> This is a BUG REPORT. I found these bugs running the Windows 2000 Pro OS.
> Please be patient as you read on.
>
> I was trying to get rid of some bugs in a new piece of code I am writing,
> which relies heavily on VPython. It was maturing nicely, but I was running
> into some problems with the scene.exit = 0 attributes of display (see here
> http://vpython.org/webdoc/visual/display.html
> <http://vpython.org/webdoc/visual/display.html> ), so I decided to try and
> upgrade my VPython, and things stopped working altogether, introducing
> problems that I have never experienced before. Thinking the problem might
be
> with me, I went back to some of my simplest applications and the demo
> programs and still noted problems. One of these aspects can be represented
> with the following small program modified from the cross product.py demo
> program below. If you run this code, it should produce a grid for the
plane
> that illustrates the visual cross product, but it does not. Please read
> further below this small program.
>
> ________________________ Test Program 1 - Modification of the
> CrossProduct.py Demo________________________
> from visual import *
> # demonstration of vector cross product
>
> print """
> Vector cross product: Red cross Green = Yellow
> Drag to change green vector
> Click to toggle fixed angle or fixed length
> """
>
> scene.title="Vector Cross Product"
> scene.width=600
> scene.height=600
> R = 0.15*4
> plane = curve(pos=[(0, -10, -10), (0, -10, 10), (0, 10,10), (0, 10, -10),
>               (0, -10, -10), (0,-6,-10), (0,-6,10), (0, -2, 10), (0, -2,
> -10),
>               (0,2,-10), (0,2,10), (0,6,10), (0,6,-10),(0,10, -10),
>
>               (0,10,-6), (0,-10,-6), (0,-10,-2), (0,10,-2), (0,10,2),
>               (0,-10,2), (0,-10,6), (0,10,6)])
> ___________________________________End of Test Program
> 1__________________________________________
>
> So, I performed some other tests. This next small program is a slight
> modification of the graphtest.py demo. Try running it. Note that no axes
are
> drawn and that you get an error. If you raise the value of -70 to say
about
> -50, or lower the 70 to something lower, the errors will go away, but you
> still get a problem with no axes being drawn. In fact, with regard to the
> axes problem, even the simplest program where you try to use the curve
> object will not draw a curve on the screen in 3D.
>
> _________________________________ Modification of graphtest.py demo
> __________________________________
> from visual.graph import *
>
> # Using a graph-plotting module
> oscillation = gdisplay(xtitle='t', ytitle='Response')
>
> list = []
> for t in arange(-70, 70, 1):
>     pos=(t, 5.0*cos(-0.2*t)) # )
>     list.append(pos)
>
> funct1 = gcurve(pos = list, color=color.cyan)
>
> ________________________________ End of Test Program 2
> _____________________________________________
>
> Finally, I tried a simple test with the last feature I was struggling
with.
> First, if I try to run the faces_heightfield.py demo, it will generate an
> error and not draw anything. Second, when I run the faces_cone.py, I do
not
> get a cone. I get a cube, and the following message...
>
>
> Traceback (innermost last)
>   File "c:\python22\lib\site-packages\visual\demos\faces_cone.py", line
13,
> in ?
>     model = faces( pos = zeros( (N*3,3), Float ), frame = f )
> TypeError: Array can not be safely cast to required type
>
> Third, if I try to run the most simple face possible, a triangle, I get
> nothing drawn at all. Try the program below...
>
> ________________________________ Simple program to draw a Triangle Face
> _____________________________________
> from visual import *
>
> f = frame()
> #scene.background = color.black
> VertexList = [(0,0,0),(1,0,0),(1,0,0)]
> NormalList = [(0,0,1),(1,0,1),(1,0,1)]
>
> surface = faces(pos=VertexList, normal=NormalList, color=color.red)
> _________________________________ End of Test Program 3
> ____________________________________________________
>
> I think a download of the previous version of Visual should be made
> available until these problems can be fixed.
>
> Thom
>
>
>
>
>
>   _____
>
>
>
<http://www.hp.com/Redirect/gw/useng_welcome/logo/=http://welcome.hp.com/cou
> ntry/us/eng/welcome.htm> HP logo
> Thom Ives, Ph.D.
>
> R&D Engineering Scientist
>
> 11413 Chinden Blvd MS 400
> Boise, ID.  83714
>
> 208.396.6880 Phone
> 208.396.3587 Fax
> tho...@hp...  <mailto:tho...@hp...>
>
> Home:
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>   _____
>
>
>
>