I've got two projects (just for starters) that would use stone or brick on 
non-flat surfaces...

I was thinking a bitmap wrapped around a cylinder should work (with a little 
bump mapping) but both projects I have in mind are conical rather than 
cylindrical.

On the slanted surface of a cone the image should get stretched or squished 
right?

The current project would be painted brick (if I don't just go with a stucco 
surface), but the other project would be stone. I've seen a tutorial on the 
web for creating good looking stone textures, but I'm not sure how they would 
work for a slanted surface.

Along the same lines I also have a cone shaped roof that I would like to tile, 
but I may be changing the cone roof to a dome of glass, so that might not be 
an issue (but the other project it will be, so I still would like to know how 
to do that also).

Any help in pointing me in the right direction would be great....

Thanks in advance.

PHIL

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Probably an image map with the bricks at the top larger in width than
the ones at the bottom would be the best idea. There is no way to escape
the distortion effect, other than to distort the image first so that it
looks right.

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This type of problem has been brought up plenty of times. I think it is time to
add conical mapping, just like we have spherical, cylindrical, and boxed. Can this
be done?

--
Anthony L. Bennett
http://welcome.to/TonyB

Non nova, sed nove.

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In article <37B1545F.EE910B4F@compuserve.com>, Chris Huff <Chr### [at] compuservecom>
wrote:
>Probably an image map with the bricks at the top larger in width than
>the ones at the bottom would be the best idea. There is no way to escape
>the distortion effect, other than to distort the image first so that it
>looks right.

I'll have to give it a try, but I'm not sure how well that'll look... maybe I 
should just model each piece of stone... hmmm...

<GRIN>

PHIL

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Here's a simple tiled roof

#macro Make_Tiles(NTiles,Height,Rad,Rot,Peak)
  #local dTheta = 360/NTiles;
  #local Pt1 = vrotate(<0,Height,Rad>,dTheta/2*y);
  #local Pt2 = <-1,1,1>*Pt1;
     union{
       #local T=0;
       #while(T<360)
           triangle{Pt1,Peak,Pt2 rotate T*y}
           cylinder{Pt1,Peak,0.05 rotate y*T}
       #declare T = T + dTheta;
     #end
    rotate y * Rot
  }
#end

#declare Roof = union{
Make_Tiles(16, -1, 1.325, 0, 0)
Make_Tiles(16, -2, 2.325, 360/16/2, y*-0.15)
Make_Tiles(16, -3, 3.250, 0, y*-0.35)
Make_Tiles(16, -4, 4.250, 360/16/2, y*-0.95)
Make_Tiles(16, -5, 5.30, 0, y*-1.65)
pigment{color rgb<.37,.62,.62>}
file://normal {wrinkles scale 0.25}
normal{facets  coords .75}
finish{crand 0.2 specular 0.5 }
}

With thanks to Dan Connelly

Hope this is of some use.

Mick


Philip Bartol <phi### [at] REMOVEMEconcentricnet> wrote in message
news:37b125ba@news.povray.org...
> I've got two projects (just for starters) that would use stone or brick on
> non-flat surfaces...
>
> I was thinking a bitmap wrapped around a cylinder should work (with a
little
> bump mapping) but both projects I have in mind are conical rather than
> cylindrical.
>
> On the slanted surface of a cone the image should get stretched or
squished
> right?
>
> The current project would be painted brick (if I don't just go with a
stucco
> surface), but the other project would be stone. I've seen a tutorial on
the
> web for creating good looking stone textures, but I'm not sure how they
would
> work for a slanted surface.
>
> Along the same lines I also have a cone shaped roof that I would like to
tile,
> but I may be changing the cone roof to a dome of glass, so that might not
be
> an issue (but the other project it will be, so I still would like to know
how
> to do that also).
>
> Any help in pointing me in the right direction would be great....
>
> Thanks in advance.
>
> PHIL
>
> -----[ to reply, the domain name is "concentric.net" ]-----
> Spelling mistakes brought to you courtesy of the
> Allentown Public School System.

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What would this conical mapping be like? I think it would be exactly the
same as cylinderical(You can't wrap a rectangular image around a cone
without distortion.).

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Chris Huff wrote:
> 
> What would this conical mapping be like? I think it would be exactly the
> same as cylinderical(You can't wrap a rectangular image around a cone
> without distortion.).

Hmmm... I wonder if you can sheer an image map... If I didn't have this
69 day render in process I would check it out myself.

-- 
Ken Tyler

See my 700+ Povray and 3D Rendering and Raytracing Links at:
http://home.pacbell.net/tylereng/index.html

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Sure, any transform can be applied to an image map-including a matrix.

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Chris Huff wrote:
> 
> What would this conical mapping be like? I think it would be exactly the
> same as cylinderical(You can't wrap a rectangular image around a cone
> without distortion.).

Yup, that sounds about right. Like trying to map a rectangular image
onto a sphere and wanting to avoid it getting pinched at the poles.
Cylindrical or conical mapping; Either way, it's gotta come to a 
point somewhere if its on a cone.

There are two approaches to this problem, depending on the look the
poster wants... either accept that the map is going to shrink near
the top... a geometrically conical stack of bricks would have to 
have each brick cut to narrow approaching the top, and get smaller 
with each level anyway... or make a map of a single row of bricks 
and fit this to each in a stack of cylinders which just happen to 
get smaller near the top, making it more like a pseudo-cone out of 
ever narrowing rings of bricks, which to my mind would look more 
like what you'd be most likely to do if you were really trying to 
shape bricks into such a structure. 

Charles
-- 
http://www.enter.net/~cfusner
"...Then darkness took me, and I strayed out of thought and time,
 and I wandered far on roads that I will not tell..." 
                              -The Two Towers, JRR Tolkien

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In article <37b1e99a@news.povray.org>, "Mick Hazelgrove"
<mha### [at] mindaswinternetcouk> wrote:
>Here's a simple tiled roof
:
>With thanks to Dan Connelly
>
>Hope this is of some use.

I'll have to give it a render to see what it does, I've got an idea from 
looking at the code, but....

Thanks, I'll let you know how it works out...

PHIL

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