Hi there,

I'm currently trying to create an animated render where individual frames
from
a video capture are image_mapped onto an object, the object has 'filter all'
applied to it so a light can be shone thru it, and the image projected onto
a
screen in the background (like a projector in a cinema). The final animation
will be used as the menu screen in a home DVD project...

When I create a shaft of light using scattering media I notice that the
shaft
only appears where an object is directly behind the rendered pixel. Can I do
anything in the media statement to allow the shaft of light to be visible
with
nothing in the background? (I wish to have a black background)...

Next question, I have thousands of png images in a directory to use as the
individual frames for my projected movie. They are image0001.png,
image0002.png,
image0003.png etc... What syntax do I need to load the filename
imagennnn.png,
where nnnn is the frame number?

Thats all, until the next thing that stumps me... :-)

Kind regards,

Chris W.
Brisbane, Australia.

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Chrisblob <blo### [at] spamtpgcomau> wrote:
> Next question, I have thousands of png images in a directory to use as the
> individual frames for my projected movie. They are image0001.png,
> image0002.png,
> image0003.png etc... What syntax do I need to load the filename
> imagennnn.png,
> where nnnn is the frame number?

concat("image", str(frame_number, -4, 0))

-- 

                                                          - Warp

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Wasn't it Chrisblob who wrote:
>
>Next question, I have thousands of png images in a directory to use as the
>individual frames for my projected movie. They are image0001.png,
>image0002.png,
>image0003.png etc... What syntax do I need to load the filename
>imagennnn.png,
>where nnnn is the frame number?

#declare FILE = concat("image",  str(frame_number, -4, 0),  ".png");
... 
  pigment {image_map {png FILE}}

When the second parameter (minimum output length) of str() is negative,
the result is padded with leading zeroes instead of spaces.

-- 
Mike Williams
Gentleman of Leisure

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Chrisblob wrote:
> Hi there,
> 
> I'm currently trying to create an animated render where individual frames
> from
> a video capture are image_mapped onto an object, the object has 'filter all'
> applied to it so a light can be shone thru it, and the image projected onto
> a
> screen in the background (like a projector in a cinema). The final animation
> will be used as the menu screen in a home DVD project...
> 
> When I create a shaft of light using scattering media I notice that the
> shaft
> only appears where an object is directly behind the rendered pixel. Can I do
> anything in the media statement to allow the shaft of light to be visible
> with
> nothing in the background? (I wish to have a black background)...
> 
Chris,

     I'm not entirely certain I understand what you're asking here, but 
let me take a hack at it.  You want a shaft of light through your 
scattering media much like you would see traversing a movie theater from 
the projection booth to the screen.

To begin with, POV can't sample along an infinite ray. (This is stated 
in the media section of the documentation.)  So you have to have 
SOMETHING in the background which would limit the length of the traced ray.

However, If your projector, or whatever, is the only light source in the 
room, then the background will probably be in deep shadow.  There should 
be several ways you can arrange this.  It may take some experimentation 
though.

I hope this helps.

Regards,

A.d.B.
> Next question, I have thousands of png images in a directory to use as the
> individual frames for my projected movie. They are image0001.png,
> image0002.png,
> image0003.png etc... What syntax do I need to load the filename
> imagennnn.png,
> where nnnn is the frame number?
> 
> Thats all, until the next thing that stumps me... :-)
> 
> Kind regards,
> 
> Chris W.
> Brisbane, Australia.
> 
> 
>

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Try using a black plane behind the scene.  If you're turning the camera,
then use a black hollow sphere.

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Bryan Valencia nous apporta ses lumieres en ce 2005-08-23 15:54:
> Try using a black plane behind the scene.  If you're turning the camera,
> then use a black hollow sphere.
> 
> 
If you make that plane or sphere finish{ambient 0 diffuse 0} it will stay black
regardless if any 
light hiting it.

Alain

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Hi there,

"Bryan Valencia" <pov### [at] spamgourmetcom> wrote:
> Try using a black plane behind the scene.  If you're turning the camera,
> then use a black hollow sphere.

The black hollow sphere is the winner! Thanks, but an interesting issue
has arisen...The closer I get to the projector (in theory shaft of light
should appear brighter), the darker the shaft of light gets. I've played
with fade_distance and fade_power, but to no avail...the beam of light
from the projector is darker right where the light source is than it is
closer to the screen...

Anyone able to point me in the direction of a workaround for that issue?

Kind regards,

Chris W,
Brisbane, Australia.

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