Well this is my first post in about 6 months or so, I've stopped using pov
for quite a while but I've decided to get back into it. This time I'm making
a conceded effort NOT to use a modeller, I've always used Moray, with the
exception of some of my earlier images, and while it is a good modeller I
sorta feel like I'm cheating ;-) Anyway people on this server tend to look
at you funny if you use a modeller, hehe. So to start things off I've
decided to take on a rather hard project. I'm modelling a tunnel made of
individual bricks with a brick floor. This is the first time I've ever used
any of the scripting capabilities of Pov and I have to say I'm enjoying it.
However I have gotten a little stuck with a Geometry/Scripting problem.
Let's see if anyone can help. Here is what I'm trying to do. I want to
create N number of bricks rotated 0 (theta) degrees. I want the bricks to be
placed end to end vertically. After about 2 hours of working this out of
paper I boiled the translation on the y axis down to this formula.

tan(0+atan2(boxh,boxw))*(cos(90-0)*boxw-cos(0)*boxh)

where 0 = theta and boxw = width and boxh=height

0 here is the angle I rotate the box. On the diagram below L is
cos(90-0)*boxw-cos(0)*boxh.
However I want the altitude up to the top of the corner, this forms a right
triangle with the diagonal of the box as a hypotenuse and L as the base.
However theta of THIS triangle is different from theta the theta on the
diagram bellow. In order to get the new angle I add the angle formed by the
base of the box and its diagonal given by atan2(boxh,boxw) to 0. I don't
know if this makes ANY sense to anyone. Anyhow the formula seems to work, a
little. As long as the angle is 45 or -45 it works perfectly, however
anything other than 45 doesn't work. I'm only in Math 12 now so there is
probably a much more consise way of doing this, but this is the way that
seemed best to me. Bellow is the entire scene file.

#include "colors.inc"


#declare boxh = 1;
#declare boxw = 10;
#declare boxl = 8;

#declare Mybox =

box{
 <-boxw/2,boxh/2,-boxl/2>
 <boxw/2,-boxh/2,boxl/2>
 texture{
  pigment {color White}
  }
}

camera {
        location <0,8,-20>
        look_at <0,0,0>

}

#declare rot = 45;

object {Mybox
   rotate <0,0,rot>}
object {Mybox
   rotate <0,0,rot>
   translate <(cos(radians(90-rot))*boxw - cos(radians(rot))*boxh),

(tan(radians(rot)+atan2(boxh,boxw))*(cos(radians(90-rot))*boxw-cos(radians(r
ot))*boxh)),
              0> }



light_source {<10,50,-100> color White}

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Attachments:
Download 'diagram.gif' (6 KB)

Preview of image 'diagram.gif'

Is this what you want?


  #include "colors.inc"
  #include "finish.inc"

  #declare boxh = 1;
  #declare boxw = 10;
  #declare boxl = 8;

  #declare Mybox =

  box{
   <-boxw/2,0,-boxl/2>
   <boxw/2,boxh,boxl/2>
   texture{
    pigment {Firebrick}
    finish {Shiny}
    }
  }

  camera {
          location 2.5*<0,8,-20>
          look_at <0,0,0>

  }


#declare BrickLength = 10;
#declare BricksInArch = 7;

#declare BrickAngle = 180/BricksInArch;
#declare ArchRadiusB = pow(pow(BrickLength,2)/(2*(1-cos(radians
(BrickAngle)))),.5);
#declare ArchRadius =
pow((pow(BrickLength,2)*(1+cos(radians(BrickAngle))))/(4*(1-cos(radians(BrickAngle)))),.5);

#macro R (Offset,Rotate)
        rotate -90*z translate Offset*x rotate Rotate*z
#end
#macro R2 (Block,NumBlocks,Angle,Radius)
         #local N = 0;
         #while (N<NumBlocks)
           object {Block R(Radius,Angle*N+Angle/2)}
           #local N = N + 1;
         #end
#end

R2 (Mybox,BricksInArch,BrickAngle,ArchRadius)

  light_source {<10,6,-100> rgb 2}


--
Dan Johnson

http://www.geocities.com/zapob

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Attachments:
Download 'brickarch.gif' (7 KB)

Preview of image 'brickarch.gif'

Wow actually that is exactly what I wanted, but I solved the problem another
way, actually I completely circumnavigated it:-) Take a look at my script in
p.t.scene-files. I'll have to take a look at your code when I get the time
though.

"Dan Johnson" <zap### [at] hotmailcom> wrote in message
news:3B01B317.40E50C26@hotmail.com...
> Is this what you want?
>
>
>   #include "colors.inc"
>   #include "finish.inc"
>
>   #declare boxh = 1;
>   #declare boxw = 10;
>   #declare boxl = 8;
>
>   #declare Mybox =
>
>   box{
>    <-boxw/2,0,-boxl/2>
>    <boxw/2,boxh,boxl/2>
>    texture{
>     pigment {Firebrick}
>     finish {Shiny}
>     }
>   }
>
>   camera {
>           location 2.5*<0,8,-20>
>           look_at <0,0,0>
>
>   }
>
>
> #declare BrickLength = 10;
> #declare BricksInArch = 7;
>
> #declare BrickAngle = 180/BricksInArch;
> #declare ArchRadiusB = pow(pow(BrickLength,2)/(2*(1-cos(radians
> (BrickAngle)))),.5);
> #declare ArchRadius =
>
pow((pow(BrickLength,2)*(1+cos(radians(BrickAngle))))/(4*(1-cos(radians(Bric
kAngle)))),.5);
>
> #macro R (Offset,Rotate)
>         rotate -90*z translate Offset*x rotate Rotate*z
> #end
> #macro R2 (Block,NumBlocks,Angle,Radius)
>          #local N = 0;
>          #while (N<NumBlocks)
>            object {Block R(Radius,Angle*N+Angle/2)}
>            #local N = N + 1;
>          #end
> #end
>
> R2 (Mybox,BricksInArch,BrickAngle,ArchRadius)
>
>   light_source {<10,6,-100> rgb 2}
>
>
> --
> Dan Johnson
>
> http://www.geocities.com/zapob
>
>


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