POV-Ray : Newsgroups : povray.binaries.images : Oriental Tileworks - strange shadows (JPG 800x600, 53 KB) Server Time
14 Aug 2024 11:21:04 EDT (-0400)
  Oriental Tileworks - strange shadows (JPG 800x600, 53 KB) (Message 1 to 7 of 7)  
From: Jörg 'Yadgar' Bleimann
Subject: Oriental Tileworks - strange shadows (JPG 800x600, 53 KB)
Date: 10 Nov 2002 08:10:06
Message: <3DCE68ED.AB09F33C@tiscalinet.de>
Hi Tracers!

There I'm again... in the meanwhile, I tried a different ornament
loosely gleaned from a Persian miniature, but when I rendered
a close-up view, I noticed a strange appearance of the superellipsoid
edges facing the light source. Firstly, I thought of
coincident surfaces (which in fact only could be true for the edge rows
of the total cube, as there are each rendered twice
because of somewhat inaccurate programming), but after an even closer
look (attached here) it became clear that it must be a
strange shadow anomaly.

The small superellipsoids use specular highlights and are also slightly
reflective; the shadow of each superellipsoid should be
solid, not only an outline... it appears almost as I had accidentally
produced some kind of caustics - but there is nothing
transparent!

See you in Khyberspace -
http://home.arcor.de/yadgar/khyberspace/index-e.html
Afghanistan Chronicle: http://home.arcor.de/yadgar/index-e.htm

Yadgar


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Attachments:
Download 'oriental_cube_01_extreme_closeup.jpg' (53 KB)

Preview of image 'oriental_cube_01_extreme_closeup.jpg'
oriental_cube_01_extreme_closeup.jpg


 

From: hughes, b 
Subject: Re: Oriental Tileworks - strange shadows (JPG 800x600, 53 KB)
Date: 10 Nov 2002 08:28:56
Message: <3dce5f18@news.povray.org>
Looks like more than just a shadow problem. What is the size of them? Very
small?


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From: Peter Popov
Subject: Re: Oriental Tileworks - strange shadows (JPG 800x600, 53 KB)
Date: 10 Nov 2002 09:02:13
Message: <9lpssu4hl9inje3anpaek94c05vj9sdsv2@4ax.com>
Looks like a precision problem to me. Just for checks, can you try
using an isosurface superellipsoid?


Peter Popov ICQ : 15002700
Personal e-mail : pet### [at] vipbg
TAG      e-mail : pet### [at] tagpovrayorg


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From: Sir Charles W  Shults III
Subject: Re: Oriental Tileworks - strange shadows (JPG 800x600, 53 KB)
Date: 10 Nov 2002 20:03:31
Message: <3dcf01e3@news.povray.org>
I devised a "perfect" tile from the superellipsoid a while back- here is the
code snippet:

#declare Ceramic = difference {
  superellipsoid {<2,.08> pigment {Tan}}
  box{<-1,-1,-.9>,1.1 pigment {Tan}}
  rotate 45*z scale 0.710
  finish {specular 1 phong 1 reflection .3}
  normal {dents frequency 3 scale <.3,.3,1>}
}

(end of code snippet)

    Here is how the finished tiles look- note the precise geometry.  Add your
grout as needed, change the color as you wish.

Cheers!

Chip Shults
My robotics, space and CGI web page - http://home.cfl.rr.com/aichip


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Attachments:
Download 'Tilesnip.jpg' (20 KB)

Preview of image 'Tilesnip.jpg'
Tilesnip.jpg


 

From: Jörg 'Yadgar' Bleimann
Subject: Re: Oriental Tileworks - strange shadows (JPG 800x600, 53 KB)
Date: 11 Nov 2002 18:37:01
Message: <3DD04D7F.758A42D@tiscalinet.de>
High!

"hughes, b." schrieb:

> Looks like more than just a shadow problem. What is the size of them? Very
> small?

Not REALLY small... in this scene, I used a matrix of 85 by 85 tiles, so each
tile is scaled to 1/85...

See you in Khyberspace!

Yadgar


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From: Jörg 'Yadgar' Bleimann
Subject: Re: Oriental Tileworks - strange shadows (JPG 800x600, 53 KB)
Date: 11 Nov 2002 18:37:30
Message: <3DD04D9D.1ADA8F05@tiscalinet.de>
High!

Peter Popov schrieb:

> Looks like a precision problem to me. Just for checks, can you try
> using an isosurface superellipsoid?

Hard to say at the moment - would using isosurfaces instead not take
forever?

See you in Khyberspace!

Yadgar


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From: Christopher James Huff
Subject: Re: Oriental Tileworks - strange shadows (JPG 800x600, 53 KB)
Date: 11 Nov 2002 18:59:41
Message: <chrishuff-AF8698.18582811112002@netplex.aussie.org>
In article <3DD04D9D.1ADA8F05@tiscalinet.de>,


> Hard to say at the moment - would using isosurfaces instead not take
> forever?

Actually, an isosurface superellipsoid could be faster, it happens in 
some cases. You could also use one isosurface for all the tiles, though 
texturing would be fun...

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: chr### [at] tagpovrayorg
http://tag.povray.org/


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