I read the docs many times, but couldn't find any reference to this
behaviour: light_sources inside a light_group do not cast shadows.

#declare Location = <0, 2, -4>;
#declare Look_at = <0, 0, 0>;

camera
{
  location  Location
  look_at   Look_at
}


#declare Thing=
text {ttf "arialbd.ttf" "TEXT" 1,0 pigment {rgb 1} translate -x-z/2}

light_group {

light_source
{ <-4, 0, -5>
  rgb 1.5
}

object {Thing}
torus {1.75,0.25 pigment {rgb 1}}

}



--
Jonathan.

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JRG wrote:
> 
> I read the docs many times, but couldn't find any reference to this
> behaviour: light_sources inside a light_group do not cast shadows.

> light_group {
> 
> light_source
> { <-4, 0, -5>
>   rgb 1.5
> }
> 
> object {Thing}
> torus {1.75,0.25 pigment {rgb 1}}
> 
> }

Your objects are part of the light_group.
I would expect light_group to behave as the old 'look_like'
extension: no self-shadow on the group.

Try putting your objects OUTSIDE of the light_group, it should work.

Post a reply to this message

I'm sorry, but it doesn't make sense to me... :(
By definition, the lightsources inside a lightgroup should light only the
objects in the lightgroup. If I want them not to cast shadows I'll put a
no_shadow flag.

--
Jonathan.


news:3BF### [at] atosorigincom...
> JRG wrote:
> >
> > I read the docs many times, but couldn't find any reference to this
> > behaviour: light_sources inside a light_group do not cast shadows.
>
> > light_group {
> >
> > light_source
> > { <-4, 0, -5>
> >   rgb 1.5
> > }
> >
> > object {Thing}
> > torus {1.75,0.25 pigment {rgb 1}}
> >
> > }
>
> Your objects are part of the light_group.
> I would expect light_group to behave as the old 'look_like'
> extension: no self-shadow on the group.
>
> Try putting your objects OUTSIDE of the light_group, it should work.

Post a reply to this message

"JRG" <jrg### [at] hotmailcom> wrote in message
news:3bfe98ed@news.povray.org...
> I'm sorry, but it doesn't make sense to me... :(
> By definition, the lightsources inside a lightgroup should light only the
> objects in the lightgroup. If I want them not to cast shadows I'll put a
> no_shadow flag.

I believe the confusion here might be that the objects won't cast a shadow
onto things outside of the particular light group.  Is that what you were
seeing?  Or are you saying that you do not see any shadows on objects from
other objects all within a certain light group?

Hmm, I've rendered your test scene and I get a shadow across the text coming
from the torus.  I thought you were not seeing shadows on a background plane
or something, so what I'm seeing here is actually expected.

What I would question as to what is expected or not is the following:

#declare Location = <0, 2, -4>;
#declare Look_at = <0, 0, 0>;

camera
{
  location  Location
  look_at   Look_at
}

#declare Thing=
text {ttf "arialbd.ttf" "TEXT" 1,0 pigment {rgb 1} translate -x-z/2}

light_group {

light_source
{ <-4, 0, -5>
  rgb 1.5
}

object {Thing}

} // end group

torus {1.75,0.25 pigment {rgb 1}} // makes shadow

In this case a person might be thinking they could shine the light through
any objects not contained within a particular light group.  Instead, it
still casts a shadow.

Bob H.

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Bob H wrote:
> Hmm, I've rendered your test scene and I get a shadow across the text
coming
> from the torus

Really?! Well, I don't (both compiles). I get that shadow only if I comment
out the light_group.

POV-Ray v3.5 Windows ME Athlon.

--
Jonathan.

Post a reply to this message

"JRG" <jrg### [at] hotmailcom> wrote in message
news:3bff576a@news.povray.org...
> Bob H wrote:
> > Hmm, I've rendered your test scene and I get a shadow across the text
> coming
> > from the torus
>
> Really?! Well, I don't (both compiles). I get that shadow only if I
comment
> out the light_group.
>
> POV-Ray v3.5 Windows ME Athlon.

Wouldn't that be strange if it's due to the Athlon processor...?
I didn't change a thing from your example script and the torus shadow
certainly crossed the text from halfway up to the lowest part.  Just to
clarify that.

Bob H.

Post a reply to this message

I don't get shadows either. Can't be the Athlon.

Marc-Hendrik

PII 450, Win98, 128 MB, Pov 3.5 beta 7.icl

Bob H. schrieb in Nachricht <3bff6344@news.povray.org>...

>Wouldn't that be strange if it's due to the Athlon processor...?
>I didn't change a thing from your example script and the torus shadow
>certainly crossed the text from halfway up to the lowest part.  Just to
>clarify that.
>
>Bob H.
>
>
>

Post a reply to this message

In article <3bff6344@news.povray.org> , "Bob H." <omn### [at] msncom> wrote:

> "JRG" <jrg### [at] hotmailcom> wrote in message
> news:3bff576a@news.povray.org...
>> Bob H wrote:
>> > Hmm, I've rendered your test scene and I get a shadow across the text
>> coming
>> > from the torus
>>
>> Really?! Well, I don't (both compiles). I get that shadow only if I
>> comment
>> out the light_group.
>>
>> POV-Ray v3.5 Windows ME Athlon.
>
> Wouldn't that be strange if it's due to the Athlon processor...?
> I didn't change a thing from your example script and the torus shadow
> certainly crossed the text from halfway up to the lowest part.  Just to
> clarify that.

I can reproduce this.  Below is a simpler version without all the
unnecessary declares and a font one can find on othere systems as well.

camera
{
  location  <0, 2, -4>
  look_at   <0, 0, 0>
}

light_group {
 light_source
 {
  <0, 5, -3>
  rgb 1
 }

 text {ttf "times.ttf" "TEXT" 1,0 pigment {rgb 1} translate <-1,1,-2>}
 torus {1.75,0.25 pigment {rgb 1}}
}


____________________________________________________
Thorsten Froehlich
e-mail: mac### [at] povrayorg

I am a member of the POV-Ray Team.
Visit POV-Ray on the web: http://mac.povray.org

Post a reply to this message

"Thorsten Froehlich" <tho### [at] trfde> wrote in message
news:3bff6ec3$1@news.povray.org...
>
> I can reproduce this.  Below is a simpler version without all the
> unnecessary declares and a font one can find on other systems as well.

Okay, are you saying I should not be seeing a shadow of the text falling
onto the torus, or that it does?  I do see the shadow.
In case this is going to matter, my system is Intel P3 with WinXP.

Bob H.

> camera
> {
>   location  <0, 2, -4>
>   look_at   <0, 0, 0>
> }
>
> light_group {
>  light_source
>  {
>   <0, 5, -3>
>   rgb 1
>  }
>
>  text {ttf "times.ttf" "TEXT" 1,0 pigment {rgb 1} translate <-1,1,-2>}
>  torus {1.75,0.25 pigment {rgb 1}}
> }
>
>
> ____________________________________________________
> Thorsten Froehlich
> e-mail: mac### [at] povrayorg
>
> I am a member of the POV-Ray Team.
> Visit POV-Ray on the web: http://mac.povray.org

Post a reply to this message

I've posted the image showing the problem to beta-test.binaries.

--
Jonathan.

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