My first try at isosurfaces. Just a single pigment on the bricks and noise3d to
gives a rustic brick appearance.  There are plenty of brick wall macros around,
but they tend to have long rendering times so I thought I would try to devise an
Isosurface representation.  The functions used to create the recessed joints are
also used to define the pigment for the bricks and the mortar.
The code used in this wall is available on my website.

rendering time:-  800x600 aa 0.3  took 27m 21s on my PII 350 

The character looking over the wall was popular in the UK in the 40s when
everything was in short supply, with the tag "Wot no ****" 
Thanks to Quadhall for the spiral Isosurface and to Samuel T Benge and Mike
Williams for their Isosurface tutors.
----------------------
dav### [at] hamiltonitecom
http://hamiltonite.com/

Post a reply to this message

Attachments:
Download 'Boz_1.jpg' (57 KB)

Preview of image 'Boz_1.jpg'

This looks good, but the vertical section of mortar seems to have
a harsh/dark shadow that doesn't look right, I'm talking about
the lower section, not the top course of upended bricks which 
doesn't have the shadow I'm talking about. 

-- 
Cheers
Steve              email mailto:ste### [at] zeroppsuklinuxnet

%HAV-A-NICEDAY Error not enough coffee  0 pps. 

web http://www.zeropps.uklinux.net/

or  http://start.at/zero-pps

 11:15pm  up 19 days,  1:36,  3 users,  load average: 1.00, 1.01, 1.00

Post a reply to this message

Steve wrote:

> This looks good, but the vertical section of mortar seems to have
> a harsh/dark shadow that doesn't look right, I'm talking about
> the lower section, not the top course of upended bricks which
> doesn't have the shadow I'm talking about.

Looks like it's just the lighting making the shadows overlap.

--
David Fontaine  <dav### [at] faricynet>  ICQ 55354965
My raytracing gallery:  http://davidf.faricy.net/

Post a reply to this message

On Sun, 29 Oct 2000 19:43:21 -0600, David Fontaine <dav### [at] faricynet> wrote:

>Steve wrote:
>
>> This looks good, but the vertical section of mortar seems to have
>> a harsh/dark shadow that doesn't look right, I'm talking about
>> the lower section, not the top course of upended bricks which
>> doesn't have the shadow I'm talking about.
>
>Looks like it's just the lighting making the shadows overlap.

You're right David.  The first of the attached  images uses a wider joint to
avoid the overlap and show that the joint surface is complete.  The second image
shows the effect of  a negative depth of joint - good for POV Waffles?
Both images show that the isosurface is tending to have problems at the edge of
the bricks - not surprising as there is an instantaneous change of slope there.
----------------------
dav### [at] hamiltonitecom
http://hamiltonite.com/

Post a reply to this message

Attachments:
Download 'IsoBrick2.jpg' (17 KB) Download 'IsoWaffle.jpg' (16 KB)

Preview of image 'IsoBrick2.jpg'

Preview of image 'IsoWaffle.jpg'

in povray.binaries.images, David Wilkinson says...
> My first try at isosurfaces. Just a single pigment on the bricks and noise3d to
> gives a rustic brick appearance.  There are plenty of brick wall macros around,
> but they tend to have long rendering times so I thought I would try to devise an
> Isosurface representation.  The functions used to create the recessed joints are
> also used to define the pigment for the bricks and the mortar.
> The code used in this wall is available on my website.
> 
> rendering time:-  800x600 aa 0.3  took 27m 21s on my PII 350 
> 
> The character looking over the wall was popular in the UK in the 40s when
> everything was in short supply, with the tag "Wot no ****" 
> Thanks to Quadhall for the spiral Isosurface and to Samuel T Benge and Mike
> Williams for their Isosurface tutors.
> ----------------------
> dav### [at] hamiltonitecom
> http://hamiltonite.com/
> 
David, would it be possible to have your code modified in such a way that 
the length of the bricks vary a little randomly? Just to use it in making 
a not too regulat floor...
-- 
Regards,  Sander

Post a reply to this message

On Mon, 30 Oct 2000 21:53:05 +0100, Sander <san### [at] stolscom> wrote:
>> 
>David, would it be possible to have your code modified in such a way that 
>the length of the bricks vary a little randomly? Just to use it in making 
>a not too regulat floor...

Hi Sander, this would be a good modification but I can't see a way to do it.  As
far as I can see there is no random function available in an isosurface.  (On
the other hand it must be possible to cook one up using clock, in fact IIRC
someone has suggested this.) 

The functions I have devised use <sin> to get a repeating pattern (modulus is
not available) and it took me quite a bit of head scratching and experimentation
to avoid color reversals at the junctions of the joints and yet have variable
width joints.  This is one of the three functions I have used;
{if(ceil(sin(pi*x+pi/2)-sin((pi/2)*(1-GROUT)))|ceil(sin(pi*(y+1))-sin(GROUT*pi/2)),Recess,0)}
Where GROUT is the thickness of the joints and Recess is the depth of the
groove.

To make these functions randomly variable, whilst avoiding color reversals would
be tricky even if a random function was available  It looks as if you will have
to use individual bricks if you want random variation :-(

Another desirable modification would be to get a random element in the
pigmentation, but again I have not yet been able to think of a way to do this.
Suggestions gratefully received :-)
----------------------
dav### [at] hamiltonitecom
http://hamiltonite.com/

Post a reply to this message

..enough already,..you're killing me!

Grim

Post a reply to this message

Sander wrote:

> David, would it be possible to have your code modified in such a way that
> the length of the bricks vary a little randomly? Just to use it in making
> a not too regulat floor...

I wouldn't know, I didn't write it.



HAHAHAHA

--
David Fontaine  <dav### [at] faricynet>  ICQ 55354965
My raytracing gallery:  http://davidf.faricy.net/

Post a reply to this message

David Wilkinson wrote:
> 
> To make these functions randomly variable, whilst avoiding color reversals would
> be tricky even if a random function was available  It looks as if you will have
> to use individual bricks if you want random variation :-(
> 
	Wouldn't something like that work?

(sin((x+(floor(y)%2)/2)*2*pi)+0.9+noise3d(x, 0, 0)*0.1) *
(sin(2*y*2*pi)+0.9) * z

	(with a threshol of 0)

	Completely untested though...

	OTOH, you do have a "random" function (noise3d) and a modulus funtion
(it's written %) in isosurfaces


-- 

* Abandon the search for truth, * mailto:ber### [at] inamecom
* Settle for a good fantasy.    * http://www.enst.fr/~jberger
*********************************

Post a reply to this message

wrote:

>
>	Wouldn't something like that work?
>
>(sin((x+(floor(y)%2)/2)*2*pi)+0.9+noise3d(x, 0, 0)*0.1) *
>(sin(2*y*2*pi)+0.9) * z
>
>	(with a threshol of 0)
>
>	Completely untested though...
>
>	OTOH, you do have a "random" function (noise3d) and a modulus funtion
>(it's written %) in isosurfaces
>
Thanks Jerome,  I didn't know about the % (or had forgotten :-) and as you say
noise3d is a random function.  Tried your function and it has bugs but could be
made to work.  I have other ideas now and am about to give them a try.
----------------------
dav### [at] hamiltonitecom
http://hamiltonite.com/

Post a reply to this message