POV-Ray : Newsgroups : povray.binaries.images : cf alpha freeze Server Time: 29 Sep 2020 09:55:15 GMT
  cf alpha freeze (Message 1 to 6 of 6)  
From: jr
Subject: cf alpha freeze
Date: 4 Dec 2019 09:40:00
Message: <web.5de77d609f95edabfeeb22ff0@news.povray.org>
"using the pigment as shown, I get the single decal but the other texture has
turned transparent and the droid looks like a weird mix of glass and (white)
emissive media."
<http://news.povray.org/povray.bugreports/message/%3Cweb.5de6653248df159ffeeb22ff0%40news.povray.org%3E/#%3Cweb.5de6653
248df159ffeeb22ff0%40news.povray.org%3E>

for this image I scaled the decal down to show the effect.  it looks like much
of the 'finish{}' survives in 3.7.1, just not the colour.


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From: Alain Martel
Subject: Re: cf alpha freeze
Date: 4 Dec 2019 14:01:55
Message: <5de7bc53$1@news.povray.org>
Le 2019-12-04 à 04:38, jr a écrit :
> "using the pigment as shown, I get the single decal but the other texture has
> turned transparent and the droid looks like a weird mix of glass and (white)
> emissive media."
>
<http://news.povray.org/povray.bugreports/message/%3Cweb.5de6653248df159ffeeb22ff0%40news.povray.org%3E/#%3Cweb.5de6653
> 248df159ffeeb22ff0%40news.povray.org%3E>
> 
> for this image I scaled the decal down to show the effect.  it looks like much
> of the 'finish{}' survives in 3.7.1, just not the colour.
> 

That droid obviously have an interior that set an IOR. We see a fair 
amount of total internal reflection.
When applying a decal, you should layer it over some other texture.

#declare textureWithDecal
texture{SomeBaseTexture}
texture{pigment{image_map png"Decal"once}}


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From: jr
Subject: Re: cf alpha freeze
Date: 4 Dec 2019 17:15:02
Message: <web.5de7e88ca76050e4feeb22ff0@news.povray.org>
hi,

Alain Martel <kua### [at] videotronca> wrote:
> Le 2019-12-04 à 04:38, jr a écrit :
> > "using the pigment as shown, I get the single decal but the other texture has
> > turned transparent and the droid looks like a weird mix of glass and (white)
> > emissive media."
> > ... > > for this image I scaled the decal down to show the effect.  it looks like
much
> > of the 'finish{}' survives in 3.7.1, just not the colour.
> >
>
> That droid obviously have an interior that set an IOR. We see a fair
> amount of total internal reflection.

in the eye glass, the only other ior I found is used in the ground plane!
(unsure why)

> When applying a decal, you should layer it over some other texture.
> #declare textureWithDecal
> texture{SomeBaseTexture}
> texture{pigment{image_map png"Decal"once}}

thanks.  I opted (before reading your post) for a second, transparent cylinder
with the decal, and union'd with the body.  for now I haven't used a texture
keyword.  will have to play some more with different arrangements, perhaps
modify the Android code.


regards, jr.


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From: Cousin Ricky
Subject: Re: cf alpha freeze
Date: 5 Dec 2019 19:30:50
Message: <5de95aea$1@news.povray.org>
On 2019-12-04 5:38 AM (-4), jr wrote:
> "using the pigment as shown, I get the single decal but the other texture has
> turned transparent and the droid looks like a weird mix of glass and (white)
> emissive media."
>
<http://news.povray.org/povray.bugreports/message/%3Cweb.5de6653248df159ffeeb22ff0%40news.povray.org%3E/#%3Cweb.5de6653
> 248df159ffeeb22ff0%40news.povray.org%3E>
> 
> for this image I scaled the decal down to show the effect.  it looks like much
> of the 'finish{}' survives in 3.7.1, just not the colour.

It's not just internal reflections; the individual parts used to 
construct the CSG are being reflected.  Try a merge rather than a union:

   AndroidRobot_Posed (yes, HeadRotate, LArmRotate, RArmRotate,
   LLegRotate, RLegRotate)


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From: Alain Martel
Subject: Re: cf alpha freeze
Date: 6 Dec 2019 01:14:26
Message: <5de9ab72$1@news.povray.org>
Le 2019-12-04 à 12:10, jr a écrit :
> hi,
> 
> Alain Martel <kua### [at] videotronca> wrote:
>> Le 2019-12-04 à 04:38, jr a écrit :
>>> "using the pigment as shown, I get the single decal but the other texture has
>>> turned transparent and the droid looks like a weird mix of glass and (white)
>>> emissive media."
>>> ... > > for this image I scaled the decal down to show the effect.  it looks like
much
>>> of the 'finish{}' survives in 3.7.1, just not the colour.
>>>
>>
>> That droid obviously have an interior that set an IOR. We see a fair
>> amount of total internal reflection.
> 
> in the eye glass, the only other ior I found is used in the ground plane!
> (unsure why)

Setting an IOR is needed when you want to use fresnel reflection. Check 
the finish of that plane. My bet is that you'll find something like :
finish{ reflection{ 1 fresnel } SomeOtherFinishComponent }

With no IOR set, it default to 1, witch effectively kill any reflection.

> 
>> When applying a decal, you should layer it over some other texture.
>> #declare textureWithDecal
>> texture{SomeBaseTexture}
>> texture{pigment{image_map png"Decal"once}}
> 
> thanks.  I opted (before reading your post) for a second, transparent cylinder
> with the decal, and union'd with the body.  for now I haven't used a texture
> keyword.  will have to play some more with different arrangements, perhaps
> modify the Android code.
> 
> 
> regards, jr.
> 

A texture{} contain a pigment and a finish, and possibly a normals 
statement.
When you use a naked pigment or finish, you effectively apply the 
default finish along with the pigment, and the default pigment with the 
finish unless you also define the other.


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From: jr
Subject: Re: cf alpha freeze
Date: 6 Dec 2019 16:00:02
Message: <web.5dea7ad9a76050e4feeb22ff0@news.povray.org>
hi,

Alain Martel <kua### [at] videotronca> wrote:
> Le 2019-12-04 à 12:10, jr a écrit :
> > Alain Martel <kua### [at] videotronca> wrote:
> >> Le 2019-12-04 à 04:38, jr a écrit :
> >>> "using the pigment as shown, I get the single decal but the other texture has
> >>> turned transparent and the droid looks like a weird mix of glass and (white)
> >>> emissive media."
> >>> ... > > for this image I scaled the decal down to show the effect.  it looks
like much
> >>> of the 'finish{}' survives in 3.7.1, just not the colour.
> >>>
> >>
> >> That droid obviously have an interior that set an IOR. We see a fair
> >> amount of total internal reflection.
> >
> > in the eye glass, the only other ior I found is used in the ground plane!
> > (unsure why)
>
> Setting an IOR is needed when you want to use fresnel reflection. Check
> the finish of that plane. My bet is that you'll find something like :
> finish{ reflection{ 1 fresnel } SomeOtherFinishComponent }

and you won.  :-)  used for the eyes only though, afaics.


> With no IOR set, it default to 1, witch effectively kill any reflection.
> ...
> When you use a naked pigment or finish, you effectively apply the
> default finish along with the pigment, and the default pigment with the
> finish unless you also define the other.

thanks.  asides like this are so valuable, even if they don't always "sink in"
at first.



Cousin Ricky:
> It's not just internal reflections; the individual parts used to
> construct the CSG are being reflected.  Try a merge rather than a union:

yes, like a .. cuddly version of the infamous T1000.  :-)  will try a merge, in
fact, will probably end up reusing chunks of your code but modified to suit.


regards, jr.


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