visualpython-users

Re: [Visualpython-users] Never realized VPython was such a great package, but still a few questions

[Bruce S. <Bru...@nc...>]

It's great that you found VPython to be useful for real work.

I'm not absolutely sure I understand the situation, but here's an 
example which may address your question:

rod = cylinder(pos=(1,2,3), axis=(5,0,0))
end_of_rod = rod.pos+rod.axis # this will be (6,2,3)

Bruce Sherwood

Stef Mientki wrote:
> hello,
> 
> While embedding VPython in my application (PyLab_Works),
> I just bumped into a real world problem of my daily work,
> which I think can well be solved with VPython.
> 
> I never used VPython before,
> but in a short evening I managed to get the basic parts working.
> How magnificient VPython is !!
> I made a litlle flash movie of it (1.6 MB), to show my problem:
>   http://mientki.ruhosting.nl/data_www/ic1.htm
> 
> The real world problem is the design of an intensive care unit,
> especially the design of the lifting arms in a small room, with 
> different bed positions.
> 
> Now I bumped into a step,
> which I probably can only solve with lots of simple math (my math is a 
> bit rusty),
> but I have the feeling, that there must be a very simple solution.
> As you can see in the movie,
> with just 10 lines of code, both lifting arms are moving,
> unbelievable (at least for me ;-)
> In fact the lifting arms should be moved by the mouse, but I doubt that 
> would be a problem.
> The movie shows 2 lifting arms
> The problem is to bend the two double arms, light blue and purple,
> for that I need to find the rotation point at the end of each first half 
> arm,
> because that's the rotation point of the second half of each arm.
> I see I can get the position, axis, and length of the first half of the arm,
> so how do I get the end that arm ?
> 
> here are some pictures of real lifting arms.
>   
> http://www.draeger.nl/MT/internet/pdf/CareAreas/ORAnesthesia/or_the_heart_of_hospital_success_en.pdf
> 
> Another question:
> is there an event when an object has moved or rotated ?
> 
> thanks,
> Stef Mientki
> 
> -------------------------------------------------------------------------
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[Visualpython-users] Never realized VPython was such a great package, but still a few questions

[Stef M. <s.m...@ru...>]

hello,

While embedding VPython in my application (PyLab_Works),
I just bumped into a real world problem of my daily work,
which I think can well be solved with VPython.

I never used VPython before,
but in a short evening I managed to get the basic parts working.
How magnificient VPython is !!
I made a litlle flash movie of it (1.6 MB), to show my problem:
  http://mientki.ruhosting.nl/data_www/ic1.htm

The real world problem is the design of an intensive care unit,
especially the design of the lifting arms in a small room, with 
different bed positions.

Now I bumped into a step,
which I probably can only solve with lots of simple math (my math is a 
bit rusty),
but I have the feeling, that there must be a very simple solution.
As you can see in the movie,
with just 10 lines of code, both lifting arms are moving,
unbelievable (at least for me ;-)
In fact the lifting arms should be moved by the mouse, but I doubt that 
would be a problem.
The movie shows 2 lifting arms
The problem is to bend the two double arms, light blue and purple,
for that I need to find the rotation point at the end of each first half 
arm,
because that's the rotation point of the second half of each arm.
I see I can get the position, axis, and length of the first half of the arm,
so how do I get the end that arm ?

here are some pictures of real lifting arms.
  
http://www.draeger.nl/MT/internet/pdf/CareAreas/ORAnesthesia/or_the_heart_of_hospital_success_en.pdf

Another question:
is there an event when an object has moved or rotated ?

thanks,
Stef Mientki

Re: [Visualpython-users] No polygon primitive in VPython?

[Bruce S. <Bru...@nc...>]

VPython has a minimalist flavor, due in part to being driven by user 
needs (and no one has to my knowledge ever before requested a polygon 
object or showed a need for it) and also to the fact that few people 
have so far stepped forward to contribute to the development of this 
open-source project.

The fact that you can draw irregular polygons (and anything else) using 
the faces object, albeit with more effort than might otherwise be 
required, and given the immense amount of other work that has had to be 
done, the development of a polygon object necessarily has had very low 
priority (actually, zero until now).

Bruce Sherwood

Roberto Aguirre Maturana wrote:
> Hi:
> 
> AFAIK, the only way to draw irregular polygons in VPython is by means of  
> faces and some polygon creation algorithm such as Ear-cutting.
> 
> Why VPython doesn't have a primitive for the creation of polygons? is  
> there any technical limitation for it?
> 
> Best regards,
> 
> Roberto Aguirre Maturana
> Santiago, Chile
> 

[Visualpython-users] No polygon primitive in VPython?

[Roberto A. M. <rha...@ho...>]

Hi:

AFAIK, the only way to draw irregular polygons in VPython is by means of  
faces and some polygon creation algorithm such as Ear-cutting.

Why VPython doesn't have a primitive for the creation of polygons? is  
there any technical limitation for it?

Best regards,

Roberto Aguirre Maturana
Santiago, Chile

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Re: [Visualpython-users] Preview of Visual 5

[Anders P. <an...@gm...>]

Very nice!
I like the new site looks. User-friendly.

/Anders


On Wed, Dec 3, 2008 at 2:14 AM, Bruce Sherwood <Bru...@nc...>wrote:

> Visual 5 is not quite ready for release, but it's very close.
>
> A preview is now available at vpython.org. Click on the link at the top
> of the page for what will be the new web site, including screen shots
> and full documentation. In the documentation section there is a page
> describing the new features.
>
> Bruce Sherwood
>
> -------------------------------------------------------------------------
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[Visualpython-users] Preview of Visual 5

[Bruce S. <Bru...@nc...>]

Visual 5 is not quite ready for release, but it's very close.

A preview is now available at vpython.org. Click on the link at the top 
of the page for what will be the new web site, including screen shots 
and full documentation. In the documentation section there is a page 
describing the new features.

Bruce Sherwood

Re: [Visualpython-users] optimise visualization for large set of data

[Roberto A. M. <rha...@ho...>]

On Mon, 01 Dec 2008 20:00:51 -0300, Bruce Sherwood  
<Bru...@nc...> wrote:

> It's not quite released yet. But almost everything is ready to go.
>
> Bruce Sherwood
>

Bruce:

I cannot stress enough how much I'm looking forward to give a try to  
Visual 5. In the meantime, can you post a screenshot or a video to see  
what can we expect of it?

Best regards,

Roberto Aguirre Maturana
Santiago, Chile.

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Re: [Visualpython-users] optimise visualization for large set of data

[Bruce S. <Bru...@nc...>]

It's not quite released yet. But almost everything is ready to go.

Bruce Sherwood

Adrián Martínez Vargas wrote:
> Estimate Bruce Sherwood
>  
> The only link that I get from http://wiki.python.org/ is e 4.beta 
> version, where I can get the 5th version?
> 
>  
> Dr. Adrian Martínez Vargas
> Revista Minería y Geología (Editor Principal)
> ISMM, Las Coloradas, s/n
> Moa, Holguín,
> Cuba
> CP. 83329
> http://www.ismm.edu.cu/revistamg/index.htm
> 
>     -----Original Message-----
>     From: Bruce Sherwood <Bru...@nc...>
>     To: Adrián Martínez Vargas <amv...@is...>
>     Cc: vis...@li...
>     Date: Sat, 29 Nov 2008 13:01:19 -0500
>     Subject: Re: [Visualpython-users] optimise visualization for large
>     set of data
> 
>     For Visual, that is a large data set in terms of having interactive
>     zoom
>     and rotate.
> 
>     Using the latest experimental version (Visual 5), which has an
>     option to
>     display cycle time (time between renders) and render time (time
>     required
>     to render the scene), on a rather fast laptop (Dell XPS with NVIdia
>     graphics), 100x100x10 boxes has a cycle time of 1.35 seconds, and a
>     render time of 0.17 seconds. In other words, Visual is hardly able to
>     deal with that many objects interactively.
> 
>     In Visual 5 there is a new object, "points", which is similar to curve
>     but the points aren't connected. With the same 100x100x10 grid there is
>     a cycle time of 0.33 seconds and a render time of 0.080 seconds.
> 
>     Bruce Sherwood
> 
> 
>     Adrián Martínez Vargas wrote:
>      > hello mail list
>      >  
>      > I have problems to visualise a large number of data, the
>     visualization
>      > windows get slowly, for example with 100x100x10 boxes it is
>     really slow,
>      > and it is not too much.
>      >  
>      > The question is: how to optimise the visualization for large set
>     of data?
>      >
>      >  your
>      > Adrian
>      >
>      >
>      >
>     ------------------------------------------------------------------------
>      >
>      >
>     -------------------------------------------------------------------------
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>     Developer's challenge
>      > Build the coolest Linux based applications with Moblin SDK & win
>     great prizes
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>     <http://moblin-contest.org/redirect.php?banner_id=100&url=/>
>      >
>      >
>      >
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> 

Re: [Visualpython-users] optimise visualization for large set of data

[A. M. V. <amv...@is...>]

EstimateBruce Sherwood







The only
link that I get from http://wiki.python.org/ [http://wiki.python.org/]
is e 4.beta version, where I can get the 5th version?
Dr. Adrian Martínez Vargas 

Revista Minería y Geología (Editor Principal) 

ISMM, Las Coloradas, s/n 

Moa, Holguín, 

Cuba 

CP. 83329 

http://www.ismm.edu.cu/revistamg/index.htm



-----Original Message-----

From: Bruce Sherwood <Bru...@nc...>

To: Adrián Martínez Vargas <amv...@is...>

Cc: vis...@li...

Date: Sat, 29 Nov 2008 13:01:19 -0500

Subject: Re: [Visualpython-users] optimise visualization for large set of 
data




For Visual, that is a large data set in terms of having interactive zoom 

and rotate.



Using the latest experimental version (Visual 5), which has an option to 

display cycle time (time between renders) and render time (time required 

to render the scene), on a rather fast laptop (Dell XPS with NVIdia 

graphics), 100x100x10 boxes has a cycle time of 1.35 seconds, and a 

render time of 0.17 seconds. In other words, Visual is hardly able to 

deal with that many objects interactively.



In Visual 5 there is a new object, "points", which is similar to curve 

but the points aren't connected. With the same 100x100x10 grid there is 

a cycle time of 0.33 seconds and a render time of 0.080 seconds.



Bruce Sherwood





Adrián Martínez Vargas wrote:

> hello mail list 

>  

> I have problems to visualise a large number of data, the visualization 

> windows get slowly, for example with 100x100x10 boxes it is really slow, 

> and it is not too much.

>  

> The question is: how to optimise the visualization for large set of data?

> 

>  your

> Adrian

> 

> 

> ------------------------------------------------------------------------

> 

> -------------------------------------------------------------------------

> This SF.Net email is sponsored by the Moblin Your Move Developer's 
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[http://moblin-contest.org/redirect.php?banner_id=100&url=/]

> 

> 

> ------------------------------------------------------------------------

> 

> _______________________________________________

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> Vis...@li...

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[Visualpython-users] is there vphyton open listener for java action?

[petro f. <pet...@gm...>]

Hi All,
I created an application with java + vphyton to  make physic simulation,
it's realy nice...just use java to call vphyton program..
the application is too simple, i need more than that, but i dont know
is vphyton has an open listener to accept an action from java or not ?
if yes, how can we do that?
And how can i replace vphyton default toolbar (toolbar on top of scene/window)
with my custom toolbar (position,icon and action.)?
thank you.

Re: [Visualpython-users] how to find help/doc files ?

[Bruce S. <Bru...@nc...>]

In the case of VPython, for most platforms the docs, which are html 
files, are in the visual folder which is in the lib/site-packages folder.

Bruce Sherwood

Stef Mientki wrote:
> hello,
> 
> For an IDE, I want to find the installed help files,
> either in the form of chm or html files.
> 
> I'm specially interested in the files for:
> - python
> - wxpython
> - vpython
> 
> but I fact I want link to all installed docs.
> 
> Is there a general way to find (by code) these docs ?
> If not,
> are there standard ways to find the docs for the above programs,
> or is it pure random where these files are located ?
> 
> thanks,
> Stef Mientki

[Visualpython-users] how to find help/doc files ?

[Stef M. <s.m...@ru...>]

hello,

For an IDE, I want to find the installed help files,
either in the form of chm or html files.

I'm specially interested in the files for:
- python
- wxpython
- vpython

but I fact I want link to all installed docs.

Is there a general way to find (by code) these docs ?
If not,
are there standard ways to find the docs for the above programs,
or is it pure random where these files are located ?

thanks,
Stef Mientki

Re: [Visualpython-users] optimise visualization for large set of data

[Bruce S. <Bru...@nc...>]

For Visual, that is a large data set in terms of having interactive zoom 
and rotate.

Using the latest experimental version (Visual 5), which has an option to 
display cycle time (time between renders) and render time (time required 
to render the scene), on a rather fast laptop (Dell XPS with NVIdia 
graphics), 100x100x10 boxes has a cycle time of 1.35 seconds, and a 
render time of 0.17 seconds. In other words, Visual is hardly able to 
deal with that many objects interactively.

In Visual 5 there is a new object, "points", which is similar to curve 
but the points aren't connected. With the same 100x100x10 grid there is 
a cycle time of 0.33 seconds and a render time of 0.080 seconds.

Bruce Sherwood


Adrián Martínez Vargas wrote:
> hello mail list 
>  
> I have problems to visualise a large number of data, the visualization 
> windows get slowly, for example with 100x100x10 boxes it is really slow, 
> and it is not too much.
>  
> The question is: how to optimise the visualization for large set of data?
> 
>  your
> Adrian
> 
> 
> ------------------------------------------------------------------------
> 
> -------------------------------------------------------------------------
> This SF.Net email is sponsored by the Moblin Your Move Developer's challenge
> Build the coolest Linux based applications with Moblin SDK & win great prizes
> Grand prize is a trip for two to an Open Source event anywhere in the world
> http://moblin-contest.org/redirect.php?banner_id=100&url=/
> 
> 
> ------------------------------------------------------------------------
> 
> _______________________________________________
> Visualpython-users mailing list
> Vis...@li...
> https://lists.sourceforge.net/lists/listinfo/visualpython-users

Re: [Visualpython-users] Unable to compile visual 4 beta

[Bruce S. <Bru...@nc...>]

My best guess would be some kind of mismatch between the Boost libraries 
and the version of Python you're building for.

But in any case, I would encourage you to set this aside for now, 
because we're about to release Visual 5, which makes this beta version 
obsolete. See the comments relevant to this in "Recent Developments" at 
vpython.org.

Bruce Sherwood

Siddhardh chandra wrote:
> Hi,
>     I am unable to compile the latest beta version of vpython. I am 
> experiencing the following errors.
> *
> In file included from /usr/include/boost/python/exception_translator.hpp:12,
>                  from ./python/cvisualmodule.cpp:11:
> /usr/include/boost/python/detail/translate_exception.hpp:34: error: 
> expected nested-name-specifier before 'add_reference'
> /usr/include/boost/python/detail/translate_exception.hpp:34: error: 
> expected ';' before '<' token
> /usr/include/boost/python/detail/translate_exception.hpp: In member 
> function 'bool boost::python::detail::translate_exception<ExceptionType, 
> Translate>::operator()(const boost::python::detail::exception_handler&, 
> const boost::function0<void>&, typename 
> boost::call_traits<Translate>::param_type) const':
> /usr/include/boost/python/detail/translate_exception.hpp:56: error: 
> expected type-specifier before 'exception_cref'
> /usr/include/boost/python/detail/translate_exception.hpp:56: error: 
> expected `)' before 'e'
> /usr/include/boost/python/detail/translate_exception.hpp:56: error: 
> expected `{' before 'e'
> /usr/include/boost/python/detail/translate_exception.hpp:56: error: 'e' 
> was not declared in this scope
> /usr/include/boost/python/detail/translate_exception.hpp:56: error: 
> expected `;' before ')' token
> *
> Could someone please help me understand what is wrong and how to correct 
> it? Thanks.
> 
> Siddhardh
> 
> 
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> 
> -------------------------------------------------------------------------
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> 
> 
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[Visualpython-users] Unable to compile visual 4 beta

[Siddhardh c. <sid...@gm...>]

Hi,
    I am unable to compile the latest beta version of vpython. I am
experiencing the following errors.
*
In file included from /usr/include/boost/python/exception_translator.hpp:12,
                 from ./python/cvisualmodule.cpp:11:
/usr/include/boost/python/detail/translate_exception.hpp:34: error: expected
nested-name-specifier before 'add_reference'
/usr/include/boost/python/detail/translate_exception.hpp:34: error: expected
';' before '<' token
/usr/include/boost/python/detail/translate_exception.hpp: In member function
'bool boost::python::detail::translate_exception<ExceptionType,
Translate>::operator()(const boost::python::detail::exception_handler&,
const boost::function0<void>&, typename
boost::call_traits<Translate>::param_type) const':
/usr/include/boost/python/detail/translate_exception.hpp:56: error: expected
type-specifier before 'exception_cref'
/usr/include/boost/python/detail/translate_exception.hpp:56: error: expected
`)' before 'e'
/usr/include/boost/python/detail/translate_exception.hpp:56: error: expected
`{' before 'e'
/usr/include/boost/python/detail/translate_exception.hpp:56: error: 'e' was
not declared in this scope
/usr/include/boost/python/detail/translate_exception.hpp:56: error: expected
`;' before ')' token
*
Could someone please help me understand what is wrong and how to correct it?
Thanks.

Siddhardh

[Visualpython-users] optimise visualization for large set of data

[A. M. V. <amv...@is...>]

hello mail list

I have
problems to visualise a large number of data, the visualization windows get
slowly, for example with 100x100x10 boxes it is really slow, and it is not 
too much.





The question
is: how to optimise the visualization for large set of data?

your
Adrian

Re: [Visualpython-users] a few simple questions about remove / clear ...

[Bruce S. <Bru...@nc...>]

I don't have the energy to try to create one pdf out of all the html 
files, but maybe someone else would like to do this. However, don't 
embark on such a project yet, because we're about to release Visual 5 
with a major restructuring of the help.

I should mention that I've sometimes run across the misperception that 
the documentation is only available on the internet, and so it's 
important to have hard copy or a pdf in case you don't have internet 
access. But in fact the help is installed on your local machine when you 
install VPython, and accessible from the IDLE help menu, so internet 
access is irrelevant.

In Visual 5 autoscale does indeed zoom out but not in, to prevent 
"fibrillation" (easily seen in the bounce.py example in the current 
Visual 3).

Your suggestion of limits on zoom is interesting. Thanks for the suggestion.

Bruce Sherwood

Stef Mientki wrote:
> thanks Bruce,
> 
> Bruce Sherwood wrote:
>> From the section of the help titled "Deleting an object" there is this:
> I thought I printed everything, but I missed that small piece of doc.
> That brings up the following:
> wouldn't be a good idea to merge all the tiny html docs into just 1 pdf 
> file ?
>> To delete a Visual object just make it invisible: ball.visible = 0
>>
>> Technical detail: If you later re-use the name ball, for example by 
>> creating a new object and naming it ball, Python will be free to 
>> release the memory used by the object formerly named ball (assuming no 
>> other names currently refer to that object).
>>
>> (If you simply make an object invisible, you might later make it 
>> visible again. But if you reassign the name, there is no longer any 
>> way for your program to access the object, so its memory can be 
>> released.)
>>
>> Similarly, a display such as scene can also be made invisible 
>> (scene.visible = 0), and if its name is reassigned the memory is 
>> released.
>>
>> If on the other hand you want to keep the window visible but remoe all 
>> objects from it, you need to make all the objects in the display 
>> invisible. In the section titled "Controlling Windows" there is this 
>> note about how to get at all the (visible) objects in a display:
>>
>> objects A list of all the visible objects in the display; invisible 
>> objects are not listed. For example, this makes all boxes in the scene 
>> red:
>>
>>    for obj in scene2.objects:
>>    if obj.__class__ == box # can say either box or 'box'
>>        obj.color = color.red
> Aha, that's what I really need,
> as I dock the scene (so it's complex to define a new one and dock it again),
> and I don't know what objects are on.
> thanks very much.
> 
> Maybe I've not yet the right to do suggestions (didn't really use Vpython),
> but on the other hand these first suggestions are often forgotten when 
> you start knowing an environement and find work arounds.
> So I do them anyway:
> - set one way autoscale: autoscale can zoom out to show the whole 
> environment if the environment grows, but it's not allowed to shrink
> - set the maximum/minimum values of zoomfactor. I use a pen instead of a 
> mouse, which is much faster, when I try to zoom, I loose my picture 
> within sceonds by zooming too much in or out. The only way to restore 
> that is to restart the program :-(
> 
> btw, I love the way VPython is automated, so you only have to deal with 
> the real problem you're interested in, great !
> 
> btw2, I'll try to make a demo this weekend, showing how I integrated 
> VPython in PyLab_Works.
> 
> cheers,
> Stef
> 
>> Bruce Sherwood
>>
>> Stef Mientki wrote:
>>> hello,
>>>
>>> I have a few simple questions,
>>> for which I can't find the answer in the doc:
>>>
>>> - how can I remove an object from the scene ?
>>> - how can I clear the whole scene ?
>>>
>>> thanks,
>>> Stef Mientki
>>>
>>>   
>>
> 
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> This SF.Net email is sponsored by the Moblin Your Move Developer's challenge
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Re: [Visualpython-users] a few simple questions about remove / clear ...

[Stef M. <s.m...@ru...>]

thanks Bruce,

Bruce Sherwood wrote:
> From the section of the help titled "Deleting an object" there is this:
I thought I printed everything, but I missed that small piece of doc.
That brings up the following:
wouldn't be a good idea to merge all the tiny html docs into just 1 pdf 
file ?
>
> To delete a Visual object just make it invisible: ball.visible = 0
>
> Technical detail: If you later re-use the name ball, for example by 
> creating a new object and naming it ball, Python will be free to 
> release the memory used by the object formerly named ball (assuming no 
> other names currently refer to that object).
>
> (If you simply make an object invisible, you might later make it 
> visible again. But if you reassign the name, there is no longer any 
> way for your program to access the object, so its memory can be 
> released.)
>
> Similarly, a display such as scene can also be made invisible 
> (scene.visible = 0), and if its name is reassigned the memory is 
> released.
>
> If on the other hand you want to keep the window visible but remoe all 
> objects from it, you need to make all the objects in the display 
> invisible. In the section titled "Controlling Windows" there is this 
> note about how to get at all the (visible) objects in a display:
>
> objects A list of all the visible objects in the display; invisible 
> objects are not listed. For example, this makes all boxes in the scene 
> red:
>
>    for obj in scene2.objects:
>    if obj.__class__ == box # can say either box or 'box'
>        obj.color = color.red
Aha, that's what I really need,
as I dock the scene (so it's complex to define a new one and dock it again),
and I don't know what objects are on.
thanks very much.

Maybe I've not yet the right to do suggestions (didn't really use Vpython),
but on the other hand these first suggestions are often forgotten when 
you start knowing an environement and find work arounds.
So I do them anyway:
- set one way autoscale: autoscale can zoom out to show the whole 
environment if the environment grows, but it's not allowed to shrink
- set the maximum/minimum values of zoomfactor. I use a pen instead of a 
mouse, which is much faster, when I try to zoom, I loose my picture 
within sceonds by zooming too much in or out. The only way to restore 
that is to restart the program :-(

btw, I love the way VPython is automated, so you only have to deal with 
the real problem you're interested in, great !

btw2, I'll try to make a demo this weekend, showing how I integrated 
VPython in PyLab_Works.

cheers,
Stef

> Bruce Sherwood
>
> Stef Mientki wrote:
>> hello,
>>
>> I have a few simple questions,
>> for which I can't find the answer in the doc:
>>
>> - how can I remove an object from the scene ?
>> - how can I clear the whole scene ?
>>
>> thanks,
>> Stef Mientki
>>
>>   
>
>

Re: [Visualpython-users] a few simple questions about remove / clear ...

[Bruce S. <Bru...@nc...>]

 From the section of the help titled "Deleting an object" there is this:

To delete a Visual object just make it invisible: ball.visible = 0

Technical detail: If you later re-use the name ball, for example by 
creating a new object and naming it ball, Python will be free to release 
the memory used by the object formerly named ball (assuming no other 
names currently refer to that object).

(If you simply make an object invisible, you might later make it visible 
again. But if you reassign the name, there is no longer any way for your 
program to access the object, so its memory can be released.)

Similarly, a display such as scene can also be made invisible 
(scene.visible = 0), and if its name is reassigned the memory is released.

If on the other hand you want to keep the window visible but remoe all 
objects from it, you need to make all the objects in the display 
invisible. In the section titled "Controlling Windows" there is this 
note about how to get at all the (visible) objects in a display:

objects A list of all the visible objects in the display; invisible 
objects are not listed. For example, this makes all boxes in the scene red:

    for obj in scene2.objects:
    if obj.__class__ == box # can say either box or 'box'
        obj.color = color.red

Bruce Sherwood

Stef Mientki wrote:
> hello,
>
> I have a few simple questions,
> for which I can't find the answer in the doc:
>
> - how can I remove an object from the scene ?
> - how can I clear the whole scene ?
>
> thanks,
> Stef Mientki
>
>   

[Visualpython-users] a few simple questions about remove / clear ...

[Stef M. <s.m...@ru...>]

hello,

I have a few simple questions,
for which I can't find the answer in the doc:

- how can I remove an object from the scene ?
- how can I clear the whole scene ?

thanks,
Stef Mientki

[Visualpython-users] Another povexport

[Bruce S. <Bru...@nc...>]

On the home page of vpython.org, another improvement in povexport, the
module which lets you export a VPython scene as a POV-ray file, from
which POV-ray can make a high-quality ray-traced scene.

This correct an error in yesterday's posting in the axis of an elllipsoid.

It implements pyramid.

It gives color to the upcoming Visual 5 distant and local lights.

There is added documentation at the start of the module.

Bruce Sherwood

[Visualpython-users] New povexport-2008-11-24

[Bruce S. <Bru...@nc...>]

On the home page of vpython.org is a new version of povexport, the 
module which lets you export a VPython scene as a POV-ray file, from 
which POV-ray can make a high-quality ray-traced scene.

The only new feature as far as Visual 3 is concerned is that it now 
handles ellipsoids. But the major development is that it is compatible 
both with Visual 3 and the upcoming Visual 5, with support in the latter 
case for transparency and local lights.

I'll mention that there has been available for some time in povexport an 
option to specify "shadowless" operation by POV-ray (don't create 
shadows). Here is sample usage:

...code to make a scene, then:
from povexport import export
export(scene, shadowless=True)

Bruce Sherwood

[Visualpython-users] Export animations to gif in linux

[P. G. C. <ozr...@gm...>]

Hi all.

I've been using vpython for simulating a vibrating string and wanted to
capture an animated gif as an example of my results for web publishing.

There're several methods explained in the FAQ <http://vpython.org/FAQ.html>,
but none of them was exactly what I was looking for, so I've choosen my own
way and here it is explained (hope to be usefull):

I use imagemagick's import command to take a screenshot of each frame. For
easily capturing just one window I need to know it's id, so I read it
through xprop.
I also use date to name each image and keep them in order.

   - In a file named id.sh I have:
   xprop | grep 'window id' | grep 'COLORMAP' | cut -d \# -f 2 | tr -d ' '
   - In my .py, after creating the scene window:
   id=string.rstrip(os.popen("sh id.sh").readlines()[0])
   - When this command is read, the mouse cursor will ask me for clicking on
   the window I want to capture, and it's id will be saved as "id".
   - Then, each frame will be captured as (folder "tmp" should exist):
   os.popen("import -window "+id+" tmp/$(date +'%s%N').png")
   - Let the script run and after finished, use imagemagick or the gimp to
   generate the animation:
   1. With imagemagick, in tmp folder:
      convert -delay 0.04 -loop 1 *.png output.gif
      2. With gimp, you can simply open the first one and then "open as
      layers" all the others. Save as gif, and follow the steps for an animated
      one (really easy). You can also apply some filters for optimization.

And that's all folks!

Here're a couple of example gifs generated:


<http://nuc5.fis.ucm.es/viajeras.gif>


<http://nuc5.fis.ucm.es/fourier.gif>

(please, excuse me for my bad English)


-- 
(^<   -- http://ozrocberg.blogspot.com
//'\
V_/_

Re: [Visualpython-users] Bug: scene.mouse.camera init

[Bruce S. <Bru...@nc...>]

Yes, my typo. I meant scene.mouse.pos.

Anders Petersson wrote:
> Are you thinking about scene.mouse.pos? That makes more sense for upper 
> left corner.
> scene.mouse.camera is the position of the camera (right?) and only 
> changes when the user right-drags in the scene.
> 
> I agree that feature requests are not a priority at the moment.
> /Anders
> 
> 
> On Thu, Nov 20, 2008 at 7:38 PM, Bruce Sherwood <Bru...@nc... 
> <mailto:Bru...@nc...>> wrote:
> 
>     For the upcoming Visual 5 on Vista (and probably on XP),
>     scene.mouse.camera does have a value immediately even though the
>     mouse is outside the window; it is the upper left corner of the
>     window. Is that what you were looking for?
> 
>     The sourceforge bug and features tracking has not been used much for
>     various reasons. However, with the upcoming release of Visual 5 it
>     might make sense to make use of it.
> 
>     I have to say that creating or extending a feature request list
>     doesn't have much point at the moment, as all hands are more than
>     full just trying to release Visual 5, and the hands and heads of
>     users will be full just trying out the new environment.
> 
>     Bruce Sherwood
> 
> 
>     Anders Petersson wrote:
> 
>         Hello
>         I have a bug report.
>         With Visual 4 beta 26 under Windows XP, scene.mouse.camera is
>         not initialized until the mouse pointer enters the scene.
>         I need that variable right away since I determine the visibility
>         of box "walls" based on camera position, to avoid hiding objects
>         inside the box.
> 
>         The bug tracking system at
>         http://sourceforge.net/projects/visualpython/ seem to be very
>         lightly used. Is this a good system to maintain?
>         In such case, now might be a good idea to revise the list, with
>         the upcoming Visual 5 and all.
> 
>         Also, the feature request list would need an overhaul if you
>         deem it worthwhile to have.
>         I certainly would be interested.
> 
>         Regards
>         /Anders
> 
> 

Re: [Visualpython-users] Bug: scene.mouse.camera init

[Anders P. <an...@gm...>]

Are you thinking about scene.mouse.pos? That makes more sense for upper left
corner.
scene.mouse.camera is the position of the camera (right?) and only changes
when the user right-drags in the scene.

I agree that feature requests are not a priority at the moment.
/Anders


On Thu, Nov 20, 2008 at 7:38 PM, Bruce Sherwood <Bru...@nc...>wrote:

> For the upcoming Visual 5 on Vista (and probably on XP), scene.mouse.camera
> does have a value immediately even though the mouse is outside the window;
> it is the upper left corner of the window. Is that what you were looking
> for?
>
> The sourceforge bug and features tracking has not been used much for
> various reasons. However, with the upcoming release of Visual 5 it might
> make sense to make use of it.
>
> I have to say that creating or extending a feature request list doesn't
> have much point at the moment, as all hands are more than full just trying
> to release Visual 5, and the hands and heads of users will be full just
> trying out the new environment.
>
> Bruce Sherwood
>
>
> Anders Petersson wrote:
>
>> Hello
>> I have a bug report.
>> With Visual 4 beta 26 under Windows XP, scene.mouse.camera is not
>> initialized until the mouse pointer enters the scene.
>> I need that variable right away since I determine the visibility of box
>> "walls" based on camera position, to avoid hiding objects inside the box.
>>
>> The bug tracking system at http://sourceforge.net/projects/visualpython/seem to be very lightly used. Is this a good system to maintain?
>> In such case, now might be a good idea to revise the list, with the
>> upcoming Visual 5 and all.
>>
>> Also, the feature request list would need an overhaul if you deem it
>> worthwhile to have.
>> I certainly would be interested.
>>
>> Regards
>> /Anders
>>
>