This is a height_field (multiple actually, tiled, but not tile-able) 
made from a nine* megapixel .png made of course from an orthogonal view 
of crackle pattern pigment on a plane.  The pigment used for the 
height_field is a *different* .png which is basically the original after 
a few bucket-fills in GIMP with different colors to different 'stones.'

I could keep-it-in-POV-Ray (no image based height_fields or image_maps) 
if I knew how to give individual stones different colors using crackle. 
  Unfortunately it looks like there's a choice between patterns that can 
give borders to cells, or patterns which can give different colors to 
different cells.

Any advice?

Thanks!
Charles

PS I'm using 1 unit = 1".  The reference axis arrows are 12" long as is 
the sphere's diameter.

*I was using 36 megapixels earlier but didn't re-do it so the below 
image has seams:

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Attachments:
Download 'crackle flagstone floor.jpg' (187 KB)

Preview of image 'crackle flagstone floor.jpg'

I forgot to mention the crackle is topped with wrinkles to try to keep 
the stone tops a little less flat.  Do they show up enough or could it 
use more?  A different scale perhaps on the wrinkles?
Charles

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Wow, I like that.

-- 
William Tracy
afi### [at] gmailcom -- wtr### [at] calpolyedu

    When you expect to live another two hundred years, you behave 
differently from when you expect to live only twenty.
     -- Kim Stanley Robinson, _Red Mars_

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William Tracy wrote:
> Wow, I like that.

I concur.

Something that I only learned after a lot of fiddling: Povray can build 
heightfields from textures generated procedurally in-memory. I can 
actually save parse time that way if the texture is detailed (large 
images take a while to load from disk).

Something like so:

height_field {
     function 400, 400 { fn_pattern(x, y, 0)}
}

-- 
William Tracy
afi### [at] gmailcom -- wtr### [at] calpolyedu

    When you expect to live another two hundred years, you behave 
differently from when you expect to live only twenty.
     -- Kim Stanley Robinson, _Red Mars_

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Have you tried 'crackle solid'?

I think that pretty much does what you want.

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In article <47e4419a@news.povray.org>,
 Charles C <"nospam a nospam.com"> wrote:

> This is a height_field (multiple actually, tiled, but not tile-able) 
> made from a nine* megapixel .png made of course from an orthogonal view 
> of crackle pattern pigment on a plane.  The pigment used for the 
> height_field is a *different* .png which is basically the original after 
> a few bucket-fills in GIMP with different colors to different 'stones.'

Looks great!

> I could keep-it-in-POV-Ray (no image based height_fields or image_maps) 
> if I knew how to give individual stones different colors using crackle. 
>   Unfortunately it looks like there's a choice between patterns that can 
> give borders to cells, or patterns which can give different colors to 
> different cells.
> 
> Any advice?

I may be misunderstanding what you are trying to do, but can you use the 
"solid" keyword with the crackle pattern? That sets each crackle to be a 
solid colour chosen from random from the colour map.

> Thanks!
> Charles

Cheers,
Edouard.

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"Charles C" <"nospam a nospam.com"> wrote in message 
news:47e4439b@news.povray.org...
>
> I forgot to mention the crackle is topped with wrinkles to try to keep the 
> stone tops a little less flat.  Do they show up enough or could it use 
> more?  A different scale perhaps on the wrinkles?
> Charles

Looks good to me! I think the wrinkle looks just right, nice and subtle. I 
think the edges look a bit odd, I'd expect them to be more vertical in 
places (obviously awkward in a height_field).

Anyway like some others have said: you want to use crackle solid. Try 
something like this:

#declare f_flagstones =
    function {
        pigment {
            pigment_pattern { crackle colour_map { [.05 rgb 0][.1 rgb 1] } }
            cubic_wave //smooth off the edges a bit
            turbulence .3
            scale .1
            pigment_map {
                [0 rgb 0]
                [1
                    average
                    pigment_map {
                        [1 crackle solid]
                        [.1 wrinkles]
                    }
                ]
            }
        }
    }

height_field {
    function 2048,2048 { f_flagstones(x,0,y).x }
}

-- 
Tek
http://evilsuperbrain.com

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William Tracy wrote:
> Wow, I like that.
> 

Thanks! :D I'm new to stonework.

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William Tracy wrote:
> William Tracy wrote:
>> Wow, I like that.
> 
> I concur.

Hehe

> 
> Something that I only learned after a lot of fiddling: Povray can build 
> heightfields from textures generated procedurally in-memory. I can 
> actually save parse time that way if the texture is detailed (large 
> images take a while to load from disk).
> 
> Something like so:
> 
> height_field {
>     function 400, 400 { fn_pattern(x, y, 0)}
> }
> 

Yes, that's what I had in mind when I mentioned 'keeping-it-in-POV'. 
After actually trying it though, on this particular machine it's taking 
longer to re-generate it than it is to load an image so I may end up 
sticking to images.  For some reason I had it in my head that a 
non-image_map based height_field worked more like an isosurface without 
a specific resolution. (Another thing I haven't learned a lot about.)

Charles

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Mark Birch wrote:
> Have you tried 'crackle solid'?
> 
> I think that pretty much does what you want.
> 
> 

Thanks, that was exactly what I needed if you don't count going 
backwards in time and fully reading the section on crackle. :D I'd 
missed that one.
Charles

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