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20 Nov 2024 06:31:37 EST (-0500)
  Wot? No shadow line artifact? (39kbu) (Message 1 to 9 of 9)  
From: Alan Holding
Subject: Wot? No shadow line artifact? (39kbu)
Date: 5 Oct 2001 17:42:03
Message: <3bbe292b@news.povray.org>
This image was the result of me following this tutorial:

http://www.digitalanimators.com/2001/10_oct/tutorials/texturing101.htm

Nothing spectacular (and I finally got my head round how Steve Cox's UV
Mapper works), but that's not the point of this post.

This is just to show that it's easy to get round the 'shadow line
artifact' problem with 3.5 now.  Simply use two copies of your object in the
scene, like this:

object {your_object no_shadow}
object {your_object no_image no_reflection}

You may need to translate the second copy of the object slightly away from
the original (I had to with one of the Coke cans), and I'm not sure what the
penalty in rendering time may be, but it's worth it, yes?

You can get the model of the can from the free section of www.3dcafe.com.

Bye,
Alan.

--
www.mp3.com/FeedingTheCats
www.btinternet.com/~manhog/


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Attachments:
Download 'coke_cans.jpg' (39 KB)

Preview of image 'coke_cans.jpg'
coke_cans.jpg


 

From: Robert Günther
Subject: Re: Wot? No shadow line artifact? (39kbu)
Date: 7 Oct 2001 09:20:05
Message: <3BC0569F.CFDC63F4@exmail.de>
Looks really good!! Crumple (is that the right word for it?) them a little bit
;-)

Robert

Alan Holding schrieb:

> This image was the result of me following this tutorial:
>
> http://www.digitalanimators.com/2001/10_oct/tutorials/texturing101.htm
>
> Nothing spectacular (and I finally got my head round how Steve Cox's UV
> Mapper works), but that's not the point of this post.
>
> This is just to show that it's easy to get round the 'shadow line
> artifact' problem with 3.5 now.  Simply use two copies of your object in the
> scene, like this:
>
> object {your_object no_shadow}
> object {your_object no_image no_reflection}
>
> You may need to translate the second copy of the object slightly away from
> the original (I had to with one of the Coke cans), and I'm not sure what the
> penalty in rendering time may be, but it's worth it, yes?
>
> You can get the model of the can from the free section of www.3dcafe.com.
>
> Bye,
> Alan.
>
> --
> www.mp3.com/FeedingTheCats
> www.btinternet.com/~manhog/
>
>  [Image]


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From: Mahalis
Subject: Re: Wot? No shadow line artifact? (39kbu)
Date: 8 Oct 2001 06:33:56
Message: <3bc18114$1@news.povray.org>
The cans look really good- did you get the image_map by rolling a can across
a scanner?
The tops look a little too plastic, though- maybe you could get some
highlights and reflections in there.


news:3BC0569F.CFDC63F4@exmail.de...
> Looks really good!! Crumple (is that the right word for it?) them a little
bit
> ;-)
>
> Robert
>
> Alan Holding schrieb:
>
> > This image was the result of me following this tutorial:
> >
> > http://www.digitalanimators.com/2001/10_oct/tutorials/texturing101.htm
> >
> > Nothing spectacular (and I finally got my head round how Steve Cox's UV
> > Mapper works), but that's not the point of this post.
> >
> > This is just to show that it's easy to get round the 'shadow line
> > artifact' problem with 3.5 now.  Simply use two copies of your object in
the
> > scene, like this:
> >
> > object {your_object no_shadow}
> > object {your_object no_image no_reflection}
> >
> > You may need to translate the second copy of the object slightly away
from
> > the original (I had to with one of the Coke cans), and I'm not sure what
the
> > penalty in rendering time may be, but it's worth it, yes?
> >
> > You can get the model of the can from the free section of
www.3dcafe.com.
> >
> > Bye,
> > Alan.
> >
> > --
> > www.mp3.com/FeedingTheCats
> > www.btinternet.com/~manhog/
> >
> >  [Image]
>


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From: Norbert Kern
Subject: Re: Wot? No shadow line artifact? (39kbu)
Date: 8 Oct 2001 23:43:08
Message: <3bc2724c$1@news.povray.org>
"Mahalis" <don### [at] fakeycom> schrieb im Newsbeitrag
news:3bc18114$1@news.povray.org...

> The cans look really good- did you get the image_map by rolling a can
across
> a scanner?
> The tops look a little too plastic, though- maybe you could get some
> highlights and reflections in there.


There is a problem with using the method described in the tutorial Alan
mentioned.
While it is easy to use an imagemap as pigment and a bumpmap as normal,

Perhaps in Pov-Ray v. 4?

Norbert


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From: Batronyx
Subject: Re: Wot? No shadow line artifact? (39kbu)
Date: 9 Oct 2001 00:14:11
Message: <3bc27993@news.povray.org>
"Norbert Kern" <nor### [at] t-onlinede> wrote in message
news:3bc2724c$1@news.povray.org...
>
> "Mahalis" <don### [at] fakeycom> schrieb im Newsbeitrag
> news:3bc18114$1@news.povray.org...
>
> > The cans look really good- did you get the image_map by rolling a can
> across
> > a scanner?
> > The tops look a little too plastic, though- maybe you could get some
> > highlights and reflections in there.
>
>
> There is a problem with using the method described in the tutorial Alan
> mentioned.
> While it is easy to use an imagemap as pigment and a bumpmap as normal,

> Perhaps in Pov-Ray v. 4?
>
> Norbert


This is the first thing I tried to do when the 3.5 betas started: use pigment
functions to vary the components of a finish statement independently.
Unfortunately, functions aren't dynamic in a finish context. POV3.5 helps some
though with the new image_pattern. You create two nearly identical textures then
pick hi-lo values for the various finish components and use the graymap in the
image_pattern to blend between them. This isn't perfect but at least it is a
vast improvement in memory savings over the 3.1 equivalent of using a
material_map with 256 nearly identical texture entries.


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From: Gilles Tran
Subject: Re: Wot? No shadow line artifact? (39kbu)
Date: 9 Oct 2001 04:18:10
Message: <3bc2b2c2$1@news.povray.org>

3bc2724c$1@news.povray.org...
> There is a problem with using the method described in the tutorial Alan
> mentioned.
> While it is easy to use an imagemap as pigment and a bumpmap as normal,


Actually, it's possible to do that with a texture_map and either
pigment_pattern or image_pattern.

#declare txt1=texture{pigment{Red}}
sphere{
    0,1
    texture{
        pigment_pattern{image_map{jpeg "testpov.jpg" map_type 1}}
//        image_pattern{jpeg "testpov.jpg" map_type 1}
        texture_map{
            [0 txt1 finish{metallic brilliance 3 reflection 0.1}]
            [1 txt1 finish{reflection 0.5}]
        }
    }
}

G.


--

**********************
http://www.oyonale.com
**********************
Graphic experiments
Pov-ray gallery


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From: JRG
Subject: Re: Wot? No shadow line artifact? (39kbu)
Date: 9 Oct 2001 13:08:36
Message: <3bc32f14@news.povray.org>
I heard about a *finish_map* in POV 4.0...

--
Jonathan.
"Norbert Kern" <nor### [at] t-onlinede> ha scritto nel messaggio
news:3bc2724c$1@news.povray.org...
>
> "Mahalis" <don### [at] fakeycom> schrieb im Newsbeitrag
> news:3bc18114$1@news.povray.org...
>
> > The cans look really good- did you get the image_map by rolling a can
> across
> > a scanner?
> > The tops look a little too plastic, though- maybe you could get some
> > highlights and reflections in there.
>
>
> There is a problem with using the method described in the tutorial Alan
> mentioned.
> While it is easy to use an imagemap as pigment and a bumpmap as normal,

> Perhaps in Pov-Ray v. 4?
>
> Norbert
>
>


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From: Alan Holding
Subject: Re: Wot? No shadow line artifact? (39kbu)
Date: 9 Oct 2001 13:58:35
Message: <3bc33acb@news.povray.org>
"Mahalis" <don### [at] fakeycom> wrote in message
news:3bc18114$1@news.povray.org...
> The cans look really good- did you get the image_map by rolling a can
across
> a scanner?

Thank you.

Rolling the can across the scanner?  Er...noooo....  (Visions of Alan
sloowwwllly trying to keep with the scanner light... D'oh!)  It comes with
the mesh of the coke can, conveniently enough.  It's on the Household
objects page of the free meshes at www.3dcafe.com.

I adapted the supplied image map in Paint Shop Pro by adding layers of metal
textures and then going beserk with the eraser.  Then I made a grayscale
version of that adapted image and used it as a bump_map in the normal of the
texture.  I was too lazy to do a 'fake' specular map but, as Gilles says
further down this tread, something like that is possible.  (He's obviously
far more patient than I am.)

Sorry for the late reply, but my HD was replaced two days ago and the
friendly engineers forgot to put the drivers back on for everything.  Life
is hard...

Bye,
Alan.
--
www.mp3.com/FeedingTheCats
http://www.btinternet.com/~manhog/


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From: Alan Holding
Subject: Re: Wot? No shadow line artifact? (39kbu)
Date: 9 Oct 2001 13:58:36
Message: <3bc33acc$1@news.povray.org>

news:3BC0569F.CFDC63F4@exmail.de...
> Looks really good!! Crumple (is that the right word for it?) them a little
bit
> ;-)
>
> Robert

Thanks, Robert.  (Sorry for the late reply.  PC problems.)

I'd like to crumple (yay!) them up, but I don't know how I could do so and
keep the UV mapping co-ordinates the same.  I suppose I could use Warp's
Mesh Compressor and Chris Colefax's associated macros to distort the mesh,
but I'm not sure if that would work either.

I'll have a go and see what happens.

Bye,
Alan.

--
www.mp3.com/FeedingTheCats
http://www.btinternet.com/~manhog/


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