visualpython-users

[Visualpython-users] Camera positioning

[Gary S. <st...@nm...>]

Hi,

Is there currently a way to _directly_ specify the camera position? Camera
position (scene.mouse.camera) can certainly be modified via scene.center
and scene.forward, but this is rather indirect and awkward if you want to,
say, just slide the camera left or right or up or down. 

Gary

Re: [Visualpython-users] rotating a scene

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

At 09:53 PM 6/4/2002 -0400, Jon Schull wrote:
>How might I programatically get a scene to continuously rotate (presumably 
>after setting userspin to 0)?

There are two answers to your question. If you want to rotate the camera 
around a fixed scene, do this:

from visual import *

cube = box()

while 1:
     rate(50)
     scene.forward = rotate(scene.forward, axis=(0,1,0), angle=0.01)

("forward" is the direction the camera is pointing in.)

If on the other hand you want to rotate the object while keeping the camera 
pointing in a fixed direction, use this loop;

while 1:
     rate(50)
     cube.rotate(axis=(0,1,0), angle=0.01)

The two versions are visually different because in the first case the 
lighting of the cube doesn't change, whereas in the second case the 
lighting does change.

Bruce Sherwood

[Visualpython-users] rotating a scene

[Jon S. <sc...@so...>]

How might I programatically get a scene to continuously rotate (presumably
after setting userspin to 0)?
------------------------------------------
Jonathan Schull, Ph.D.
Founder and President
SoftLock.com dba Digital Goods
Sc...@Di...
recent bio: http://conferences.oreillynet.com/cs/p2pweb2001/view/e_spkr/1017
978-764-1058 cell and v-mail
978-568-9916 landline
978-246-0487 fax
------------------------------------------

Re: [Visualpython-users] VPython on brand new iBook

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

I would guess you're unlikely to see much difference in performance of 
anything, including VPython, in changing from 600 to 700 MHz. Perhaps the 
larger VRAM would make a difference in the OpenGL graphics.

The OSX installation is indeed scary, but several people have gotten 
through it. I don't see how it would screw anything up on your machine. The 
"fink" installation procedures build a separate directory (/sw) into which 
all the applications go, with the exception of some parts of the X11 window 
system, so it is easy to delete stuff by deleting everything in /sw.

Bruce Sherwood

At 01:51 PM 02/05/24 -0400, Joe Heafner wrote:
>Hi.
>
>Last Saturday, I purchased a new Apple iBook -- 600MHz G3, 100MHz bus, 
>256K L2 cache, 256MB RAM, 8MB VRAM). The following Monday morning, the 
>Apple web site showed new specs -- 700MHz G3, 100MHz bus, 512K L2 cache, 
>128MB RAM (I bought 128MB extra), 16MB VRAM. I can exchange mine for a 
>$129 restocking fee + $60 installation (to swap out the Airport card and 
>extra RAM). My question is this:
>
>Would it be worth it to me to swap for the newer iBook for the purposes of 
>running VPython?
>
>Another question: I'm a brand new Mac user. The VPython installation looks 
>daunting under OS X, and I really don't want to screw up my brand new 
>iBook. Could someone comfort me about the installation procedure? :-)
>
>
>Cheers,
>Joe Heafner - Instructional Astronomy and Physics
>CVAC Home Page <http://users.vnet.net/heafnerj/cvac.html>
>My Book <http://www.willbell.com/new/fundephcomp.htm>
>My Home Page <http://users.vnet.net/heafnerj/>
>
>
>_______________________________________________________________
>
>Don't miss the 2002 Sprint PCS Application Developer's Conference
>August 25-28 in Las Vegas -- http://devcon.sprintpcs.com/adp/index.cfm
>
>_______________________________________________
>Visualpython-users mailing list
>Vis...@li...
>https://lists.sourceforge.net/lists/listinfo/visualpython-users

[Visualpython-users] VPython on brand new iBook

[Joe H. <hea...@vn...>]

Hi.

Last Saturday, I purchased a new Apple iBook -- 600MHz G3, 100MHz bus, 256K L2 cache, 256MB RAM, 8MB VRAM). The following Monday morning, the Apple web site showed new specs -- 700MHz G3, 100MHz bus, 512K L2 cache, 128MB RAM (I bought 128MB extra), 16MB VRAM. I can exchange mine for a $129 restocking fee + $60 installation (to swap out the Airport card and extra RAM). My question is this:

Would it be worth it to me to swap for the newer iBook for the purposes of running VPython?

Another question: I'm a brand new Mac user. The VPython installation looks daunting under OS X, and I really don't want to screw up my brand new iBook. Could someone comfort me about the installation procedure? :-)


Cheers,
Joe Heafner - Instructional Astronomy and Physics
CVAC Home Page <http://users.vnet.net/heafnerj/cvac.html>
My Book <http://www.willbell.com/new/fundephcomp.htm>
My Home Page <http://users.vnet.net/heafnerj/>

Re: [Visualpython-users] redhat woe

[Andy D. <dou...@la...>]

On Thu, 9 May 2002, Bruce Sherwood wrote:

> Another alternative would be for the install script to do a "which"   
> operation on python2.2 and use the results to construct the correct   
> locations. Unfortunately I'm not sufficiently facile with shell       
> programming to do this quickly. (But I'd accept advice or help!)      

I was planning to look at this sometime in the next few weeks.  A
Python-based installer would be better, but some shell-script hackery will
get us pretty far, I think.

-- 
    Andy Dougherty		dou...@la...
    Dept. of Physics
    Lafayette College, Easton PA 18042

[Visualpython-users] New Linux installer

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

I posted a new VPython installer for Linux. The only change was to    
delete some *.o files in the cvisual/CXX folder. Because these object 
files had been compiled on an Intel machine, they caused problems for 
someone trying to compile Visual on a Mac running Linux.              
                                                                      
Bruce Sherwood                                                        
Joining the NCSU Dept. of Physics June 1, 2002                        

Re: [Visualpython-users] redhat woe

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

Thanks for the reports. I've updated the installation documentation on
the VPython web site to explain that the Makefile as well as the      
install script have to be changed if python2.2 isn't in               
/usr/local/bin.                                                       
                                                                      
A better installer would use the Python "dist-utils" mechanism,       
because it runs through Python, and Python knows where Python is.     
David Andersen wrote a dist-utils component, but I haven't yet        
incorporated it into the full installer.                              
                                                                      
Another alternative would be for the install script to do a "which"   
operation on python2.2 and use the results to construct the correct   
locations. Unfortunately I'm not sufficiently facile with shell       
programming to do this quickly. (But I'd accept advice or help!)      
                                                                      
> The problem at my end was that when I installed Py 2.2 -- from      
> http://python.org/ftp/python/2.2.1/rpms/python2-2.2.1-1.src.rpm,    
> rather than from the object rpm -- it was put into /usr/bin/ and    
> /usr/include/ rather than (as the VP scripts expect) /usr/local/bin/
and                                                                   
> /usr/local/include/ .                                               
>                                                                     
> --                                                                  
> Anton Sherwood, http://www.ogre.nu/                                 
                                                                      
Bruce Sherwood                                                        
Joining the NCSU Dept. of Physics June 1, 2002                        

Re: [Visualpython-users] redhat woe

[Anton S. <br...@po...>]

The problem at my end was that when I installed Py 2.2 -- from
http://python.org/ftp/python/2.2.1/rpms/python2-2.2.1-1.src.rpm,
rather than from the object rpm -- it was put into /usr/bin/ and
/usr/include/ rather than (as the VP scripts expect) /usr/local/bin/ and
/usr/local/include/ .

-- 
Anton Sherwood, http://www.ogre.nu/

Re: [Visualpython-users] redhat woe

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

I'm not absolutely sure what's going on, but I note that Python.h is  
in the Python "include" folder, and arrayobject.h is in the Python    
Numeric "include" folder. Evidently something is not set properly to  
have those include folders searched for references to *.h files.      
                                                                      
Evidently very close....                                              
                                                                      
Bruce Sherwood                                                        
Joining the NCSU Dept. of Physics June 1, 2002                        

[Visualpython-users] redhat woe

[Anton S. <br...@po...>]

tried it again with a fresh Red Hat 7.1, and got (if memory serves)
*different* errors, which is something.

-- 
Anton Sherwood, http://www.ogre.nu/

Re: [Visualpython-users] VPython for Linux PPC ?

[Andy D. <dou...@la...>]

On Wed, 8 May 2002, Gerhard Reuteler wrote:

> Is it possible to compile  VPython under Debian Linux PPC? I found some 
> binary files which of course are not usable with the ppc. 

Probably.  I successfully compiled it under Debian/SPARC.  My brief notes
are archived at http://www.vpython.org/morelinux.html.
If you have specific problems, don't be afraid to ask.

Once the semester ends and I no longer am assigning VPython homework, I'll
look at rebuilding with the lastest versions.

-- 
    Andy Dougherty		dou...@la...
    Dept. of Physics
    Lafayette College, Easton PA 18042

[Visualpython-users] VPython for Linux PPC ?

[Gerhard R. <ger...@ao...>]

Is it possible to compile  VPython under Debian Linux PPC? I found some 
binary files which of course are not usable with the ppc. 
-- 
Gerhard Reuteler , Reitweg 26d , A-6830 Rankweil
Tel: 0043 5522 48113

[Visualpython-users] Re: Trouble installing on Debian

[Neal M. H. <nh...@do...>]

A couple of replies with respect to a "segfault" problem on Debian
(and also on my highly non-standard Caldera) mentioned problems
with passing const char * pointers.   Those points may be valid,
but consider the original method causing the problem:

void PythonType::name( const char* nam )
{
   table->tp_name = const_cast<char *>( name );
}

I bet that line should be:

   table->tp_name = const_cast<char *>( nam );

Otherwise, the code is storing a pointer to the method
and not the string -- a simple typo.

Changing it this way fixes the segfault on my Caldera system.

Cheers, and thanks for making it easy for me to fix
the problem get VPython to run ..

neal


     FROM: Bruce Sherwood
     DATE: 04/26/2002 06:40:58
     SUBJECT:  [Visualpython-users] Trouble installing on Debian
      
>     Here is some nice detective work by Yves Bailly in France. I should 
>     incorporate his change, but in the meantime here is what he found. I'm 
>     puzzled that others running on Debian did not run into this problem.
>
>     Bruce Sherwood
>
>     --On Friday, April 26, 2002 1:57 AM +0200 Yves BAILLY 
>     <<EMAIL: PROTECTED>> wrote:
>
>     > Hello,
>     >
>     > First of all, I have to say : contragulation for your great work !
>     >
>     > Now, my problem :
>     > I tried to install VPython on a Debian "sid", using :
>     > - Python 2.2.1
>     > - Numeric 21.0
>     > - GtkGlArea 1.2.3
>     > - Mesa which comes with XFree86 4.1.0
>     >
>     > Everything compiles fine, but when running
>     > from visual import *
>     > ...I was always getting a segfault.
>     >
>     > I dig a little bit, and found this in cvisual/CXX/Src/cxx_extensions.cxx :
>     > void PythonType::name( const char* nam )
>     > {
>     >        table->tp_name = const_cast<char *>( name );
>     > }
>     > The segfault seemed to occure during this method.
>     >
>     > Considering the char* is a rather strange thing, that should always be
>     > used with care, moreover when you give a litteral string to a function,
>     > I just modified this method a little, to allocate and duplicate the
>     > string :
>     > void PythonType::name( const char* nam )
>     > {
>     >        char* str = new char[strlen(nam)+1] ;
>     >        strcpy(str, nam) ;
>     >        table->tp_name = const_cast<char *>( str );
>     > }
>     >
>     > ...and now it works fine, I can even use the KineticsKit !
>     >
>     > Just a quick hack, for sure there should something better (nicer).
>     >
>     > Best regards,
>     >
>     > --
>     > ( | Yves Bailly  : http://kafka-fr.net   | -
>     > //\ | Linux Dijon  : http://www.coagul.org | //\
>     > \_/ | Don d'organe : http://adot21.free.fr | \_/`
>

-- 
Neal Holtz                             http://www.docuweb.ca/~nholtz
Dept. of Civil and Environmental Engineering,   Carleton University,   
Ottawa, Ontario, Canada K1S 5B6.                   nh...@do...

Re: [Visualpython-users] Installation problem under Debian woody Linux i386

[Andy D. <dou...@la...>]

On Wed, 1 May 2002, Gerhard Reuteler wrote:

> Python2.2, gtklarea 1.2.3, ... everything is on board, so: Compilation runs 
> fine! But
> -- when I start idle:
> 
>  it complains: it is not possible to load _tkinter, 
> python is not configured for tkinter.

I have it running mostly ok under Debian/woody, but I haven't updated
everything lately.  Is python2.2 available for woody yet?  If so, have you
also installed python22-tk (or whatever it's called?)

At the time I built VPython, I had to compile and install my own Python22
(and extensions, such as Numeric and Tk) as well as my own libgtkglarea.
I built the versions that came with the Visual .tar.gz bundle.  

Lastly, what version of gcc are you using?  I'm not C++ fluent, but it's
possible that gcc-3 handles things ever so slightly differently from
gcc-2.95 (which is what I used).

I'm planning to look at the build process again, but I'm not touching
my current working installation till after this semester is over :-).

-- 
    Andy Dougherty		dou...@la...
    Dept. of Physics
    Lafayette College, Easton PA 18042

[Visualpython-users] Installation problem under Debian woody Linux i386

[Gerhard R. <ger...@ao...>]

Python2.2, gtklarea 1.2.3, ... everything is on board, so: Compilation runs 
fine! But
-- when I start idle:

 it complains: it is not possible to load _tkinter, 
python is not configured for tkinter.

-- when I use Xemacs: 

,,from visual import *" gives a segmentation fault, 
perhaps like reported by Ives Bailly. But when I follow his modification of 
the method ,,name", I get a Parse error  in the third line ,, table->tp_name 
= const_cast .....before  ''(".
As I don't know anything about C, I am lost.
Best regards

-- 
Gerhard Reuteler , Reitweg 26d , A-6830 Rankweil
Tel: 0043 5522 48113

[Visualpython-users] (no subject)

[Gerhard R. <ger...@ao...>]

confirm 463159

[Visualpython-users] New installer for Mac OS9

[Bruce S. <ba...@an...>]

At http://vpython.org is a new VPython installer for Mac OS9 running on 
Python 2.2.1 (also works with Python 2.2).

With the availability of this installer, the vpython.org installers for all 
platforms are up to date. In particular, they all have support for 
importing visual.controls, and a bug with toggle switches on Mac OS9 is 
fixed.

Bruce Sherwood

Re: [Visualpython-users] Trouble installing on Debian

[Andy D. <dou...@la...>]

On Fri, 26 Apr 2002, Bruce Sherwood wrote:

> Here is some nice detective work by Yves Bailly in France. I should
> incorporate his change, but in the meantime here is what he found. I'm
> puzzled that others running on Debian did not run into this problem.

I'm not surprised.  Debian systems cover a huge range of versions of
packages.  This report is based on "sid", the perpetually unstable
development branch of Debian. (The Toy Story reference to the kid who
keeps blowing up toys is deliberate.)  The "stable" release, code-named
"potato" has much older versions of nearly every package and library.  
I'm not that surprised that one works and the other doesn't.  Handling
read-only strings is also something that different compilers could
possibly handle differently at different optimization levels.

Nonetheless, I think he's right.  Literal strings should be considered
read-only.  If it's going to be modified (I haven't checked the code
myself) a strdup() (or equivalent) might be called for.

> > Now, my problem :
> > I tried to install VPython on a Debian "sid", using :
> > - Python 2.2.1
> > - Numeric 21.0
> > - GtkGlArea 1.2.3
> > - Mesa which comes with XFree86 4.1.0
> >
> > Everything compiles fine, but when running
> > from visual import *
> > ...I was always getting a segfault.
> >
> > I dig a little bit, and found this in cvisual/CXX/Src/cxx_extensions.cxx :
> > void PythonType::name( const char* nam )
> > {
> >	 table->tp_name = const_cast<char *>( name );
> > }

-- 
    Andy Dougherty		dou...@la...
    Dept. of Physics
    Lafayette College, Easton PA 18042

[Visualpython-users] Trouble installing on Debian

[Bruce S. <ba...@an...>]

Here is some nice detective work by Yves Bailly in France. I should 
incorporate his change, but in the meantime here is what he found. I'm 
puzzled that others running on Debian did not run into this problem.

Bruce Sherwood

--On Friday, April 26, 2002 1:57 AM +0200 Yves BAILLY 
<kaf...@ne...> wrote:

> Hello,
>
> First of all, I have to say : contragulation for your great work !
>
> Now, my problem :
> I tried to install VPython on a Debian "sid", using :
> - Python 2.2.1
> - Numeric 21.0
> - GtkGlArea 1.2.3
> - Mesa which comes with XFree86 4.1.0
>
> Everything compiles fine, but when running
> from visual import *
> ...I was always getting a segfault.
>
> I dig a little bit, and found this in cvisual/CXX/Src/cxx_extensions.cxx =
:
> void PythonType::name( const char* nam )
> {
>	 table->tp_name =3D const_cast<char *>( name );
> }
> The segfault seemed to occure during this method.
>
> Considering the char* is a rather strange thing, that should always be
> used with care, moreover when you give a litteral string to a function,
> I just modified this method a little, to allocate and duplicate the
> string :
> void PythonType::name( const char* nam )
> {
>	 char* str =3D new char[strlen(nam)+1] ;
>	 strcpy(str, nam) ;
>	 table->tp_name =3D const_cast<char *>( str );
> }
>
> ...and now it works fine, I can even use the KineticsKit !
>
> Just a quick hack, for sure there should something better (nicer).
>
> Best regards,
>
> --
> (=B0< | Yves Bailly  : http://kafka-fr.net   | -=B0)
> //\ | Linux Dijon  : http://www.coagul.org | //\
> \_/ | Don d'organe : http://adot21.free.fr | \_/`

[Visualpython-users] Mac OSX

[Bruce S. <ba...@an...>]

Updated at http://vpython.org the installer for Mac OSX to include the new 
visual.controls module (plus documentation and demo program).

Don't yet have this in the Mac OS9 version.

Bruce Sherwood

[Visualpython-users] controls documentation

[Bruce S. <ba...@an...>]

I added documentation to the Visual reference manual for the new controls 
module (buttons, sliders, toggle switches, pull-down menus), including the 
web-site documentation.

I also updated the installers for Windows and Linux to have the new 
controls.py module (so that you import it from visual.controls), and to 
have a small controls programs added to the demos (to advertise this 
capability), as well as adding documentation to the reference manual. I 
haven't updated the Mac installers.

Bruce Sherwood

P.S. My first attempt to send this failed in an odd way. I apologize if 
this shows up in duplicate.

[Visualpython-users] controls.py

[Bruce S. <ba...@an...>]

After a fair amount of testing, and given its general utility, I've added 
controls.py to the visual folder (download from CVS at sourceforge.net, or 
download Visual-2002-04-17.zip from http://vpython.org, in the download 
section for all platforms).

This module offers buttons, toggle switches, sliders, and pull-down menus. 
The full capabilities can be seen from the test routine found at the end of 
controls.py (simply execute controls.py to see what happens). Eventually 
there will be documentation added to the Visual reference manual.

I would be pleased to receive suggestions/criticisms, and even more pleased 
for someone to make major improvements, either in the way the module works 
or in the appearance of the control objects.

Here is a short example, which displays a button and changes the button 
text every time you click the button. The Python construction "lambda:" is 
required for controls.py to have the correct context ("namespace") for 
calling the specified routine.

from visual.controls import *

def change(): # Called by controls when button is clicked
    if b.text == 'Click me':
        b.text = 'Try again'
    else:
        b.text = 'Click me'

c = controls() # Create controls window
# Create a button in the controls window:
b = button( pos=(0,0), width=60, height=60, text='Click me', action=lambda: 
change() )

while 1:
    c.interact() # Check for mouse events and drive specified actions

Re: [Visualpython-users] How to draw a polyhedron?

[Bruce S. <ba...@an...>]

Nice polyhedron. You can improve the appearance by inserting this line just 
before the while:

a.display.autoscale = 0

Without it, with this particular solid, Visual's attempt to autoscale is 
incorrectly making small adjustments to the camera position.

Nope, no glass yet. Transparency and real time are somewhat incompatible 
and require a major restructuring of Visual.

Bruce Sherwood

Re: [Visualpython-users] How to embed into Tk?

[Phlip <ppl...@om...>]

Phlip sez:
> VPython users:
>
> I'm auditioning 3D graphics libraries, and need to demonstrate VPython
> grafted into a Frame. The rest of our UI is Tkinter (and uses
> multidimensional data), and a window floating over it revealing this data
> would damage the user's experience. I can't find an examples on the net; so
> (once again ;-) what's the most rudimentary one possible?

VPython wraps Gtk and gtkglarea, so this appears problematic. I will now be 
Googling for such inanities as "put a Gtk widget into a Tk window".

-- 
  Phlip
        http://www.greencheese.org/PeaceAndCalm
"Remember always that you not only have the right to be an
individual, you also have an obligation to be one."  -- Eleanor
Roosevelt