visualpython-users

[Visualpython-users] Cast a shadow

[Nick L. <ni...@ja...>]

Hello,

I've have just installed vpython and have to say I am loving messing around
with it.

Anyhoo, I've had a look through the archives but unfortunately I could not
find a search function for past posts, hence my question, which I'm sure
must of been asked before ;)

Is there anyway to have objects cast a shadow ? I can see that when I rotate
a box object that there is a shadow but when I move a sphere object around
inside a box (or between two boxes as in the tutorial) there is no shadow of
the sphere.

I can get the current vectors for the default 2 lights (print scene.lights)
but I'm unsure of how to manipulate my own lights (or the default ones) to
get a moving object inside a box to generate a shadow.

So basically can anyone please give me a quick rundown on how to generate my
own lighting to enable shadows on moving objects ?

I have attached my code in the hope that it my help to explain what I'm
trying to do.

Many thanks,
Nick .

Re: [Visualpython-users] Cast a shadow

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

Sorry, currently there's no way to cast shadows. And you can only put 
lights at infinity. Jonathan Brandmeyer is working on a version that 
will let you put lights anywhere, but even with that advance there won't 
be shadows, which typically require ray-tracing, which is slow. A minor 
footnote is that at vpython.org there is a routine for exporting a 
VPython scene to Pov-Ray, a freeware ray tracer, which does produce shadows.

Bruce Sherwood

Nick Lunt wrote:

>Hello,
>
>I've have just installed vpython and have to say I am loving messing around
>with it.
>
>Anyhoo, I've had a look through the archives but unfortunately I could not
>find a search function for past posts, hence my question, which I'm sure
>must of been asked before ;)
>
>Is there anyway to have objects cast a shadow ? I can see that when I rotate
>a box object that there is a shadow but when I move a sphere object around
>inside a box (or between two boxes as in the tutorial) there is no shadow of
>the sphere.
>
>I can get the current vectors for the default 2 lights (print scene.lights)
>but I'm unsure of how to manipulate my own lights (or the default ones) to
>get a moving object inside a box to generate a shadow.
>
>So basically can anyone please give me a quick rundown on how to generate my
>own lighting to enable shadows on moving objects ?
>
>I have attached my code in the hope that it my help to explain what I'm
>trying to do.
>
>Many thanks,
>Nick .
>
>  
>

RE: [Visualpython-users] Cast a shadow

[Nick L. <ni...@ja...>]

Many thanks Bruce. No need to apologise though, vpython is excellent as it
is. It's helping me in learning python and damn good fun to boot :)

I'll go have a look at Pov-Ray and see what it's all about.

Thanks again,
Nick .


> -----Original Message-----
> From: Bruce Sherwood [mailto:Bru...@nc...]
> Sent: 01 October 2005 19:53
> To: Nick Lunt
> Cc: Vpython
> Subject: Re: [Visualpython-users] Cast a shadow
>
>
> Sorry, currently there's no way to cast shadows. And you can only put
> lights at infinity. Jonathan Brandmeyer is working on a version that
> will let you put lights anywhere, but even with that advance there won't
> be shadows, which typically require ray-tracing, which is slow. A minor
> footnote is that at vpython.org there is a routine for exporting a
> VPython scene to Pov-Ray, a freeware ray tracer, which does
> produce shadows.
>
> Bruce Sherwood
>
> Nick Lunt wrote:
>
> >Hello,
> >
> >I've have just installed vpython and have to say I am loving
> messing around
> >with it.
> >
> >Anyhoo, I've had a look through the archives but unfortunately I
> could not
> >find a search function for past posts, hence my question, which I'm sure
> >must of been asked before ;)
> >
> >Is there anyway to have objects cast a shadow ? I can see that
> when I rotate
> >a box object that there is a shadow but when I move a sphere
> object around
> >inside a box (or between two boxes as in the tutorial) there is
> no shadow of
> >the sphere.
> >
> >I can get the current vectors for the default 2 lights (print
> scene.lights)
> >but I'm unsure of how to manipulate my own lights (or the
> default ones) to
> >get a moving object inside a box to generate a shadow.
> >
> >So basically can anyone please give me a quick rundown on how to
> generate my
> >own lighting to enable shadows on moving objects ?
> >
> >I have attached my code in the hope that it my help to explain what I'm
> >trying to do.
> >
> >Many thanks,
> >Nick .
> >
> >
> >
>
>
>
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