Hi,
  I need to get rid of the shadows made by other polygon on a special one... 
the other polygons need the shadows but not this one.  This polygon should have
an ambient lighting and no shadow.

The shadow is created by a point light...  Is there anything that can do this?
(clipped_by? no_shadow?, etc...)

Thanks,
  Simon

-- 
+--------------------------------+---------------------------+
| Simon Lemieux                  | http://666Mhz.myip.org/   |
| Email : lem### [at] yahoocom | Povray and OpenGL Gallery |
+--------------------------------+---------------------------+

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"Simon Lemieux" <lem### [at] yahoocom> wrote in message
news:3AFE9D2C.63C3A623@yahoo.com...
>   I need to get rid of the shadows made by other polygon on a special
one...
> the other polygons need the shadows but not this one.  This polygon should
have
> an ambient lighting and no shadow.
>
> The shadow is created by a point light...  Is there anything that can do
this?
> (clipped_by? no_shadow?, etc...)

If it's a separate polygon statement (a CSG of several of those?) then I'd
expect no_shadow to do just that.  Hmm, no, I misread what you were saying.

How about MegaPov and the light groups?  That could do it. Assign all but
the singled out polygon to one light, then another light just for the
unshadowed one.
So... if it's a polygonal section of one polygon statement I guess you'll
need to break it up into more than one polygon statement first.

Bob H.

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> If it's a separate polygon statement (a CSG of several of those?) then I'd
> expect no_shadow to do just that.  Hmm, no, I misread what you were saying.
> 
> How about MegaPov and the light groups?  That could do it. Assign all but
> the singled out polygon to one light, then another light just for the
> unshadowed one.
> So... if it's a polygonal section of one polygon statement I guess you'll
> need to break it up into more than one polygon statement first.

I was able to fake something for it by adding spotlights directed on that
polygon, that got rid of most of the shadow, but I'm not pretty proud about
it...  I needed this for tonight and now it's gone...  But for my personnal
knowledge and for next time, I wonder how I could do it with only the Official
Povray!

no_shadow controls the Casting of shadow, if I set all the other polygons to
no_shadow, then there is indeed no shadow on my central polygon, but there is
also no shadow on the smaller polygons all around...  Adding no_shadow to my
central polygon only stops the cast of its shadow on the other polygons (but
there is still the shadow of the other polygons on it...)

Thanks,
  Simon

-- 
+--------------------------------+---------------------------+
| Simon Lemieux                  | http://666Mhz.myip.org/   |
| Email : lem### [at] yahoocom | Povray and OpenGL Gallery |
+--------------------------------+---------------------------+

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>  I need to get rid of the shadows made by other polygon on a special one... 

Well, this wouldn't do precisely what it sounds like you're looking for, but
it might be close enough.

Declare the pigment of the special polygon as something like:
	color some_small_num * <red, green, blue>

And then in the finish statement, put:
	ambient 1/some_small_num

Where some_small_num is something like 0.001

So although all the other polygons will cast shadows onto the object, the
difference between the directly lit, and the shadowed area will be very small,
but the high ambient will cause the object to essentially glow at whatever 
pigment value you used.

I don't know if this would work (havn't tried it), as the renderer might not
retain enough precision in the light level calculation, in which case it might
end up rounding the very small rgb components to zero, and the high ambient
wouldn't restore them.

Jamie

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Simon Lemieux <lem### [at] yahoocom> wrote:
:   I need to get rid of the shadows made by other polygon on a special one... 

  You could use the "vampire object" trick in order to achieve this.
  Apply a bounding box to the polygon and scale it so that it gets very
small and very close to the camera; that is, apply these transformations
to the bounding box of the polygon:

translate -CameraLocation
scale .001
translate CameraLocation

  Of course this has the side-effect that the polygon will disappear from
all the reflections as well.

-- 
#macro N(D,I)#if(I<6)cylinder{M()#local D[I]=div(D[I],104);M().5,2pigment{
rgb M()}}N(D,(D[I]>99?I:I+1))#end#end#macro M()<mod(D[I],13)-6,mod(div(D[I
],13),8)-3,10>#end blob{N(array[6]{11117333955,
7382340,3358,3900569407,970,4254934330},0)}//                     - Warp -

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