clipka <ano### [at] anonymousorg> wrote:
>
> My spontaneous guess would be that the use of `acos` here might be to
> blame, as it will only return values in the range from -90 to +90
> degrees, losing information about the quadrant. Maybe try rephrasing
> that as an expression satisfying the form `atan(A/B)`, and then use
> `atan2(A,B)` instead to make sure you get the quadrant right.
>
> I haven't fully thought it through, but I think the following should do
> the trick:
>
>     #local wall_th = degrees(atan2(wall_vec.x, wall_vec.z));
>
> (You may need to tweak the expression a bit, e.g. swapping the `.x` and
> `.z`, and/or changing the sign of one or both of them.)

Well, since no one has actually posted about the solution to this given there I
thought I would try it. Rendered okay as done for macro portion below.

I was looking at it yesterday and thought it must be possible just to put
conditional #if regarding certain degrees for wall_th but only got me thoroughly
confused. I'm no math wizard, by far! Just wanted to see how this went.

#macro Wall(START, END, HEIGHT, BSIZE, MWIDTH)

    #local wall_vec = vnormalize(END - START);
    #local wall_vec = <wall_vec.u, 0, wall_vec.v>;
    #local wall_dlength = vlength(END - START);
    #local wall_perp = vcross(wall_vec, y);
  // #local wall_th  = degrees(acos(vdot(wall_vec,x))); // replaced with...
#local wall_th = degrees(atan2(wall_vec.z, wall_vec.x)); // ...Clipka answer
    #local remainder = 0;
// commented intersection removed from here
    union {
    #local wall_aheight = 0.0;
    #while(wall_aheight < HEIGHT)
    #local wall_alength = 0.0;
        #while(wall_alength < wall_dlength)
            #local nbLength =
            (remainder > 0 ? remainder : min(BSIZE.x, wall_dlength -
wall_alength));
            #local remainder = 0;
            object {
             Block(nbLength, BSIZE.y, BSIZE.z) rotate -(wall_th)*y
translate <START.u, wall_aheight, START.v> + wall_alength*wall_vec
} // object closing brace
        #local wall_alength = wall_alength + nbLength + MWIDTH;
        #end
    #local remainder = BSIZE.x - nbLength;
    #local wall_aheight = wall_aheight + BSIZE.y + MWIDTH;
    #end
    } // union closing brace
// prism removed from here
#end

Post a reply to this message