If you translate a light source, and that light source has a
projected_through object specified, the projected_ through object is *not*
translated along with it. Is that the intended behavior?

#declare obj = sphere{0,1}

light_source {
    -5*y
    rgb1
    projected_through {obj}
    translate 10*y
} // this light source shines *down* below the X-Z plane.

- Slime
[ http://www.teja.nu/slime/ ]
[ http://www.teja.nu/slime/images/ ]

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On Tue, 25 Sep 2001 18:49:03 -0400, Slime wrote:
>If you translate a light source, and that light source has a
>projected_through object specified, the projected_ through object is *not*
>translated along with it. Is that the intended behavior?

I think the projected_through object should be translated too.  Anyone
have any objections?

-- 
#macro R(L P)sphere{L F}cylinder{L P F}#end#macro P(V)merge{R(z+a z)R(-z a-z)R(a
-z-z-z a+z)torus{1F clipped_by{plane{a 0}}}translate V}#end#macro Z(a F T)merge{
P(z+a)P(z-a)R(-z-z-x a)pigment{rgbt 1}hollow interior{media{emission T}}finish{
reflection.1}}#end Z(-x-x.2y)Z(-x-x.4x)camera{location z*-10rotate x*90}

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"Ron Parker" <ron### [at] povrayorg> wrote in message
news:slr### [at] fwicom...
> On Tue, 25 Sep 2001 18:49:03 -0400, Slime wrote:
> >If you translate a light source, and that light source has a
> >projected_through object specified, the projected_ through object is *not*
> >translated along with it. Is that the intended behavior?
>
> I think the projected_through object should be translated too.  Anyone
> have any objections?
>

It depends. Considering a relatively flat object, and the behavior of the light
when the ray bisecting its major axis is perpendicular: does the behavior change
if the ray isn't perpendicular? If so, (and even without testing, I expect it
would) then perhaps it should just be an 'option'.


--
Batronyx ^"^
bat### [at] cadronhsacom
http://www.batronyx.com

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"Batronyx" <bat### [at] cadronhsacom> wrote in message
news:3bb1588c$1@news.povray.org...
> "Ron Parker" <ron### [at] povrayorg> wrote in message
> news:slr### [at] fwicom...
> > On Tue, 25 Sep 2001 18:49:03 -0400, Slime wrote:
> > >If you translate a light source, and that light source has a
> > >projected_through object specified, the projected_ through object is
*not*
> > >translated along with it. Is that the intended behavior?
> >
> > I think the projected_through object should be translated too.  Anyone
> > have any objections?
> >
>
> It depends. Considering a relatively flat object, and the behavior of the
light
> when the ray bisecting its major axis is perpendicular: does the behavior
change
> if the ray isn't perpendicular? If so, (and even without testing, I expect
it
> would) then perhaps it should just be an 'option'.

Wha-?  ;-)

Yeah, it changes because of distances to scene objects being illuminated, if
that's what you meant.  That happens anyhow.

The way it is now sets up a kind of static scene object as a shaped window
of light being shone which means the light source is the variable as to
where light falls.
A union to the light source could mean having unchanging relative positions
so that both object and light are variable together as one.  Is now
actually, just by adding the same transformation into the projected_through.
Double effort I guess and that's probably enough reason to consider it.  If
it can be done already though and addition of a unlinking (hmmm,
"unlink"...) is necessary then most important choice would be which to
default to.  If done at all.

Bob H.

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Ron Parker <ron### [at] povrayorg> wrote:
: I think the projected_through object should be translated too.  Anyone
: have any objections?

  Of course it should. The projected_through is the same kind of property
as looks_like, and it's very natural that it's "attached" to the light and
moves with it.

  Also other transformations should affect it (rotate, scale...).

-- 
#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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On 25 Sep 2001 23:23:31 -0400, Ron Parker wrote:
>On Tue, 25 Sep 2001 18:49:03 -0400, Slime wrote:
>>If you translate a light source, and that light source has a
>>projected_through object specified, the projected_ through object is *not*
>>translated along with it. Is that the intended behavior?
>
>I think the projected_through object should be translated too.  Anyone
>have any objections?

Turns out that other transformations were already modifying the 
projected_through object, so this was a no-brainer.  Fixed for the next
beta.

-- 
#local R=rgb 99;#local P=R-R;#local F=pigment{gradient x}box{0,1pigment{gradient
y pigment_map{[.5F pigment_map{[.3R][.3F color_map{[.15red 99][.15P]}rotate z*45
translate x]}]#local H=pigment{gradient y color_map{[.5P][.5R]}scale 1/3}[.5F
pigment_map{[.3R][.3H][.7H][.7R]}]}}}camera{location.5-3*z}//only my opinions

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