displacement
KTleafD
(
float     xyscale=4,xyamp=0.5,xyoffset=0;
float     zscale=0,zamp=0.05,zoffset=0;
float     wavescale=1,zmax=0.1,waveoffset=0;
float     startwave=0,endwave=1;
float     xytype=0,ztype=0,wavetype=1;
point     Center=point(0,0,0),wavezP=point(0,0,-1)
)

{
point    PP,NF,NFz;
float    ss;
float    wavexymag,wavezmag,mag;
float    wavetheta;

PP=transform("object",P);
NF=normalize(N);
NFz=wavezP-Center;
NFz=normalize(NFz);
/*printf ("NFz = %p\n",NFz);*/

ss=s*wavescale;
wavetheta=(cos(2*PI*ss+2*PI*waveoffset)+wavetype)/2;
wavetheta=mix(startwave*PI/2,endwave*PI/2,wavetheta);

wavezmag=2*zmax*(1-sin((PI/2)-wavetheta));
wavexymag=wavezmag*tan((PI/2)-(wavetheta/2));
wavezmag*=t;
wavexymag*=t;

P+=wavexymag*NF+wavezmag*NFz;
N=calculatenormal(P);


ss=s*xyscale;
mag=(cos(2*PI*ss+2*PI*xyoffset)+xytype)/2;
mag*=xyamp;
P+=mag*normalize(NF);
N=calculatenormal(P);

ss=s*zscale;
mag=(cos(2*PI*ss+2*PI*zoffset)+ztype)/2;
mag*=zamp;
P+=mag*NFz;
N=calculatenormal(P);

}