Bill Hails <bil### [at] europeyahoo-inccom> wrote:
> generating the normals isn't all that hard.
>
> Each vertex is touched by three or more triangles.
>
> For each triangle you take a vector perpendicular to it's plane,
> of length proportional to the length of that triangle's two edges that
> intersect with the point in question (I think that's vcross() not sure
> now because it's been a while).
>
> Then you average those vectors to give you the normal at that point.

It wasn't the actual calculation that was putting me off, just the amount of
thought and coding required to implement it! It would indeed be vcross(),
and there's VPerp_To_Plane(v1,v2) in math.inc, although I fail to see the
difference between them to be honest.

Each vertex is touched by eight triangles, although I could probably get
away with averaging the normals to the four non-planar quadrilaterals
touching each vertex (which amounts to the same thing, at least in my
head). I'm going to have to re-write my main loop...

Well, I've thought about it now, so obviously I'm not going to be happy
until I've done it! :)

To be continued...

Bill

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What are s.day and Bill Pragnell using for a news reader? Gravity, both 
the older version and the new open source one refuse to decode the 
messages and display them... Its quite annoying and frankly I hate every 
other news reader I have ever tried to use.

-- 
void main () {

    call functional_code()
  else
    call crash_windows();
}

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Patrick Elliott wrote:
> What are s.day and Bill Pragnell using for a news reader? Gravity, both 
> the older version and the new open source one refuse to decode the 
> messages and display them... Its quite annoying and frankly I hate every 
> other news reader I have ever tried to use.
> 

According to the headers, both are using the web-interface from 
povray.org. I attached the source of Sean's message, perhaps you can 
figure out what keeps your agent from displaying the messages.


HTH,
Florian



From: "s.day" <s.d### [at] uelacuk>
Date: Tue,  2 May 2006 09:45:01 EDT
Newsgroups: povray.binaries.images
Message-ID: <web.4457625d782f552aea4cafdb0@news.povray.org>
Subject: Re: Realistic bricks
References: <web.44574b069e74fc96731f01d10@news.povray.org>
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X-Newsreader: POV-Ray Web Interface
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Looks very interesting, I had a similar idea myself a while ago but
unfortunately did not know how to create the rounded box using meshes. I
would certainly be very interested in the source code when it is finished.

Sean

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> "Patrick Elliott" <sha### [at] hotmailcom> wrote in message
news:MPG.1ec14e1d990869a7989f03@news.povray.org...
> What are s.day and Bill Pragnell using for a news reader? Gravity, both
> the older version and the new open source one refuse to decode the
> messages and display them... Its quite annoying and frankly I hate every
> other news reader I have ever tried to use.

Looks like they're both using the web interface

"X-Newsreader: POV-Ray Web Interface"

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Bill Pragnell wrote:
> Martin Magnusson <martin@-xx-blecket-xx-.org> wrote:
> 
>>How about using smooth_triangles instead? In the example you showed, it
>>looks like you used "flat" triangles. That should make them look
>>smoother, and probably better, at close range.
> 
> 
> This is very true. 

I believe it is only relatively true.  It has long been my intuition 
that high-res, unsmoothed triangles would create more believeable 
surfaces for many materials, especially skin.  Proving it is just one of 
the many things on my to-do list, lol.  So I am looking forward to your 
source if for no other reason than ease of running tests at different 
resolutions.


FWIW a while back I was playing a bit with getting the weathering in 
face stones.  The examples attached are in fact iso's using round box 
macros from iso_csg.inc with some displacement, but the streaking 
effects might interest you.

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Attachments:
Download 'img.2009.jpg' (52 KB) Download 'img.2012.jpg' (54 KB)

Preview of image 'img.2009.jpg'

Preview of image 'img.2012.jpg'

s.day wrote:

> Looks very interesting, I had a similar idea myself a while ago but
> unfortunately did not know how to create the rounded box using meshes. I
> would certainly be very interested in the source code when it is finished.

You could try downloading my surface subdivision suite 
(http://www.geocities.com/evilsnack/nsss.htm).  Feed it a simple 
box-shaped mesh (you can use quadrilateral faces if you want), specify 
sharp edges, subdivide it a couple times, add some perturbation, and 
then use one of the macros to spit out a mesh.

Regards,
John

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hey, man, call me old fashioned, but i still believe textured bricks have a
lot going for it. :)

Your post has challenged me to produce an impacting textured brick wall.
Hope you guys like it...


code:

camera { location .6*<-4.1,4.3,-4.1> look_at <-.8,1.6,0> angle 20 }

light_source { <-2,1.6,-.4>*10 1 }
light_source { <-.2,3.4,-4>*12 .7
 area_light 3*x,3*y,3,3 adaptive .0001 jitter
}


#declare n_brick_wall =
normal { brick
 normal {brick normal{ granite .3 }, normal{ gradient y } bump_size 2.4 },
 normal { average
  normal_map {
   [1.1 granite bump_size -.6 ramp_wave scale .32]
   [.9 bumps bump_size .7 turbulence .6 scale .62]
   [1.4 quilted control0 .2 control1 .2 bump_size 4.8 scale <8,3,3.8> warp {
repeat 3*y offset x*4} ]
  }
 }
 mortar .2
 bump_size 2.4
}

#declare p0 = pigment { rgb .8 }
#declare p1 =
pigment { bozo
 color_map {
  [0 rgb 1]
  [.46 rgb <.95,.68,.71>]
  [1 rgb .8*<.94,.64,.59>]
 }
 turbulence 1.8 scale 6
}

#declare t_brick_wall =
texture {
 pigment { brick pigment { p0 }, pigment { p1 } mortar .34 turbulence .1 }
 normal { n_brick_wall turbulence .071 }
 finish { ambient .32 diffuse .34 specular .3 roughness .28 }
 scale .05
}

box { -.5,.5 scale <2.4,2,.2>
 texture { t_brick_wall }
 translate y
}

plane { y,0 pigment { rgb .9 } finish { ambient .3 diffuse .4 }}

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Attachments:
Download 'brickwall.jpg' (105 KB)

Preview of image 'brickwall.jpg'

Wow lot's of nice brick walls here. Very impressed with the textured-only
version.

It's funny, because just a couple of days ago I started putting together a
macro for creating brick walls - and I am trying to make it as flexible as
possible (offering (so far) 3 quality "settings" (plain boxes,
superellipsoids or isosurface blocks for bricks), variable dimensions,
randomness along X and Y, and mortar-settings).

I'm more than happy to post source code and images once I've worked more on
it, but I was going to ask first -

I'd like to include as many options as possible in my macro; if you have a
brick/brickwall/brick texture/etc piece of source code, do I have your
permission to include this in my macro?

Thanks!

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"nemesis" <nam### [at] gmailcom> schreef in bericht
news:web.44582f18782f552a11c80c7b0@news.povray.org...
> hey, man, call me old fashioned, but i still believe textured bricks have
a
> lot going for it. :)
>
> Your post has challenged me to produce an impacting textured brick wall.
> Hope you guys like it...
>
>
Hmm... top and right edges of bricks show also the mortar texture. That is
not right :-)

Thomas

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"Bill Pragnell" <bil### [at] hotmailcom> wrote:
> Each vertex is touched by eight triangles,
Whooooops obviously I meant six... :

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