我正在尝试将一些代码从Processing转换为POVray格式。这是原始的:
http://www.openprocessing.org/sketch/17344
这是我创建的POVray版本:
#declare TWO_PI = 2 * pi;
#declare iNx = 32; // the number of "horizontal" lines per charge, not taking into account iXmin
#declare iNy = 32; // the number of "vertical" lines per charge
#declare iXmin = 24; // size of the empty hole for each charge, measured in "horizontal" lines
#declare iSym = 5; // number of charges arranged around the origin
#declare iSx = 2;
#declare iSy = 2;
#declare fMouseY = 300; // need to get rid of this
#declare bLines = true; // show lines connecting the points
#declare bInside = true; // are the curved lines inside or outside of the reference shape? or, are the charges inside or outside the reference shape?
#macro mag(fX, fY)
dist(fX, fY, 0, 0)
#end
#macro dist(fX1, fY1, fX2, fY2)
sqrt(pow(fX2 - fX1, 2) + pow(fY2 - fY1, 2))
#end
#macro calc()
#local fY1 = 0;
#local fX1 = 0;
#local fX2 = exp(fX1) * cos(fY1);
#local fY2 = exp(fX1) * sin(fY1) + fMouseY;
#if (bInside)
#local fD = pow(mag(fX2, fY2), 1/iSym);
#else
#local fD = pow(mag(fX2, fY2), -1/iSym);
#end
#local fArg = atan2(fX2, fY2) * -1/iSym;
#local fX3 = fD * cos(fArg)/TWO_PI;
#local fY3 = fD * sin(fArg)/TWO_PI;
vlength(<fX3, fY3, 0,>) // return
#end
#macro draw()
#for (i, 0, iNy - 1)
#local fY = i * TWO_PI/iNy;
#for (j, iXmin * iSx, iNx * iSx - 1)
#local fX1 = j * TWO_PI/iNx/iSx;
#local fX2 = (j + 1) * TWO_PI/iNx/iSx;
lines(fn(fX1, fY), fn(fX2, fY))
#end
#end
#for (i, iXmin, iNx)
#local fX = i * TWO_PI/iNx;
#for (j, 0, iNy * iSy - 1)
#local fY1 = j * TWO_PI/iNy/iSy;
#local fY2 = (j + 1) * TWO_PI/iNy/iSy;
lines(fn(fX, fY1), fn(fX, fY2))
#end
#end
#end
#macro lines(aP1, aP2)
#for (i, 0, iSym - 1)
#local fX1 = aP1[i][0];
#local fY1 = aP1[i][2];
#local fX2 = aP2[i][0];
#local fY2 = aP2[i][3];
sphere
{
<fX1, fY1, 0,>/calc(),
0.005
pigment {color rgb x}
}
#if (bLines)
cylinder
{
<fX1, fY1, 0,>/calc(),
<fX2, fY2, 0,>/calc(),
0.005
pigment {color rgb x}
}
#end
#end
#end
// this is where the magic happens ...
#macro fn(fX, fY)
#local aP = array[iSym][2];
#local fX1 = exp(fX) * cos(fY);
#local fY1 = exp(fX) * sin(fY) - fMouseY;
#if (bInside)
#local fD = pow(mag(fX1, fY1), 1/iSym);
#else
#local fD = pow(mag(fX1, fY1), -1/iSym);
#end
#local fArg = atan2(fX1, fY1) * -1/iSym;
#for (i, 0, iSym - 1)
#local fX2 = fD * cos(fArg + i * TWO_PI/iSym);
#local fY2 = fD * sin(fArg + i * TWO_PI/iSym);
#local aP[i][0] = fX2/TWO_PI;
#local aP[i][4] = fY2/TWO_PI;
#end
aP //return
#end
draw()
然而,结果在一方面被打破。现在有线条纵横交错,应该应该遵循平滑的曲线。参见:
我看了看,发现我做错了什么。我怀疑一些三角函数如atan2在两种语言中表现不同。也许一种语言不能处理大于2 * pi的输入?
这可能吗?否则我没有任何线索,并希望得到一些帮助。