Okay Ken... you have a couple of magic numbers in here (a magic number
is a number that is just there for some reason and no logical
explaination is known except by the author)  The most important one is
1.6*pi/90-bb where did you get this figure?  I am trying to figure it
out, and my guess is that you just kept tweaking it until there weren't
any gaps...Also, where did you come up with the origial scale for the
box?  

Steve


Ken wrote:
> 
> Greetings Math Wizards !
> 
>   Below are two versions of pov script both currently producing exactly
> the same object, a semi-hemisphere or half dome if you wish. The first
> is out of a scene I have been working on and it suited my needs for the
> one scene. After establishing a a procedure I thought it would be nice
> if I could parameterize the script so it is self adjusting. By this I
> mean I would like to be able to provide the 3 dimensions of a box and
> the desired radius for the dome and the script takes care of the rest
> as far as number of objects, rotation angles, etc. It would also be nice
> to have a choice between half dome, half sphere, and full sphere versions
> but I am not going to push my luck at this point.
>   Anyway I started working on the improved version and got so tangled up
> I stopped and said enough. I'm at the stage where if someone will help
> finish it I would appreciate it greatly. I just can't seem to get everything
> working together in unison for the desired output. I have commented the
> major operating points of the script and it shouldn't be too difficult
> to follow. The feeble attempts I made at getting it to work have been
> eliminated so as not to confuse the issue. Only the identifiers have been
> left in place as a guide. I can see a definite candidate for a macro here
> but would rather the help you provide stays within the current format.
> I need to learn how to convert stuff like this to macros myself and this
> will be my first case study.
> 
> Thanks !
> 
> P.S. If you indent the script I won't cry too much ;^ {
> 
>   camera{location<0,20,-65>look_at 20*y}
> 
>   light_source{<  0,500,-900>rgb 1}
>   light_source{<  0,  5,-100>rgb 1}
> 
>   // original working code
> 
>   #declare HalfDome_1 =
>   union {
>   #declare aa = 0;
>   #while  (aa < 90)
>   #declare bb = 0;
>   #while  (bb < 45)
> 
>   box{-.5,.5
>   scale     <.05, 1.50, 1.50>         // Box scale
>   translate <-40, 0.00,    0>         // Translate from origin
>   rotate    <0.0, 0.00,-2*bb>         // rotate for first verticle section of dome
>   scale     <1.0, 1.00,1.6+pi/90*-bb> // Scale each box smaller as it goes up
>   rotate    <0.0, 2*aa, 0.00>         // rotate scaled section horizontily to form
dome
>   translate <0.0, 0.75, 0.00> }       // Translate bottom edge to y*0
> 
>   #declare bb = bb+1;
>   #end
>   #declare aa = aa+1;
>   #end }
> 
>   // New code that works but needs help - lots of
> 
>   #declare HalfDome_2 =
>   union {
>   #declare Xscale    = 0.05;         // Box scale
>   #declare Yscale    = 1.50;         // Box scale
>   #declare Zscale    = 1.50;         // Box scale
>   #declare Rad       = 40.0;         // Dome radius
>   #declare Trnslt    = <-Rad, 0, 0>; // Translate from origin
>   #declare HSegNum   = 180/2;        // Number of horizontal segments
>   #declare VSegNum   = HSegNum/2;    // Number of verticle   segments
>   #declare aa        = 0;
>   #while  (aa        < HSegNum)
>   #declare bb        = 0;
>   #while  (bb        < VSegNum)
>   #declare Rotate1   = <0,0,-2*bb>;  // rotate value for one verticle section of
dome
>   #declare RotScale  = <1,1,Yscale+.1+pi/HSegNum*-bb>; // Rotation scaler
>   #declare Rotate2   = <0,2*aa, 0>;  // rotate values horizontal sections of dome
> 
>   box{-.5,.5
>   scale     <Xscale,Yscale,Zscale>  // Scale of Box
>   translate Trnslt                  // Translate from origin
>   rotate    Rotate1                 // rotate to create first verticle slice of dome
>   scale     RotScale                // Scale each box smaller as it goes up
>   rotate    Rotate2                 // Rotate scaled verticle section to create dome
>   translate <0,Yscale*.5,0>}        // Translate bottom edge to y*0
> 
>   #declare  bb = bb+1;
>   #end
>   #declare  aa = aa+1;
>   #end }
> 
>   #declare Tex = texture{pigment{rgb 1} finish{ambient .4 diffuse .2}}
> 
>   object{HalfDome_1 rotate 180*y texture{Tex}}
> 
>   //object{HalfDome_2 rotate 0*y texture{Tex}}
> 
> --
> Ken Tyler
> 
> mailto://tylereng@pacbell.net

Post a reply to this message