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in news:XnsAA1B5C2AAB745seed7@news.povray.org ingo wrote:
> I.i.r.c you can also declare a macro (with trace) as __Fuv. You may
> have to fiddle a bit with that though.
>
>
Had a quick look. TwoVarSurf part of makesmesh.inc has to changed a bit
for that, file below. It doesn't change anything for existing scenes, but
makes it possible to declare the macor __Fuv and use that together with
TwoVarSurfCalc().
Also added the documentation that is missing in the distribution.
---%<------%<------%<---
// former "twovar.inc"
TwoVarSurf(__Fuv, Urange, Vrange, Iter_U, Iter_V, FileName): Builds a
mesh2 surface of
a function with two variables (u,v).
__Fuv : the function to be turned into a mesh2.
Urange : A 2-D vector that gives the boundaries of u.
Vrange : A 2-D vector that gives the boundaries of v. These are the
ranges
within whitch the surface is calculated.
Iter_U : Sets the resolution of the mesh in the u range.
Iter_V : Sets the resolution of the mesh in the v range.
FileName : The name of the file to whitch the mesh will be written. If is
an
empty string (""), no file will be written.
If the file extension is 'obj' a Wavefront objectfile will be
written.
If the extension is 'pcm' a compressed mesh file is written.
If a file name is given, the macro will first check if it
already exists.
If that is so, it will try to parse the existing file unless
it's a '*.obj',
'*.pcm' or '*.arr' file as POV-Ray can not read them directly.
In this case a new
mesh will be generated, but the existing files will _not_ be
over-written.
Use:
#include twovar.inc
#declare __Fuv=function(u,v){(10*sin((u^2+v^3)^0.5))/(2+cos((u^2+y^2)^
0.5))}
object {
TwoVarSurf(<-6,6>,<-6,6>,20,20,"")
uv_mapping
pigment{checker color rgb <0,0,0.2> color rgb <1,0.85,0.85> scale
0.5}
finish{specular 0.4}
rotate <-110,45,0>
}
*/
#macro TwoVarSurf(__Fuv__, Urange, Vrange, Iter_U, Iter_V, FileName)
#ifdef(__Fuv) #undef __Fuv #end
#declare __Fuv= function(u,v){__Fuv__(u,v)}
TwoVarSurfCalc(Urange, Vrange, Iter_U, Iter_V, FileName)
#end
#macro TwoVarSurfCalc(Urange, Vrange, Iter_U, Iter_V, FileName)
#declare Build=CheckFileName(FileName);
#if(Build=0)
#debug concat("\n Parsing mesh2 from file: ", FileName, "\n")
#include FileName
object{Surface}
#else
#local Umin=Urange.u;
#local Umax=Urange.v;
#local Vmin=Vrange.u;
#local Vmax=Vrange.v;
#local dU=Umax-Umin;
#local dV=Vmax-Vmin;
#local iU=dU/Iter_U;
#local iV=dV/Iter_V;
#local NumVertices=(Iter_U+1)*(Iter_V+1);
#declare NumFaces=Iter_U*Iter_V*2;
#debug concat("\n Calculating ",str(NumVertices,0,0)," vertices for
", str(NumFaces,0,0)," triangles\n\n")
#local VecArr=array[NumVertices]
#local NormArr=array[NumVertices]
#local UVArr=array[NumVertices]
#local Count=0;
#local I=0;
#while (I<Iter_V+1)
#local V=RangeMM(I,0,Iter_V,Vmin,Vmax);
#local J=0;
#while (J<Iter_U+1)
#local U=RangeMM(J,0,Iter_U,Umin,Umax);
#if(J=0)
#local P0=<U,V,__Fuv(U,V)>;
#local P2=<U-iU,V,__Fuv(U-iU,V)>;
#else
#local P0=P1;
#local P2=P0;
#end
#local P1=<U+iU,V,__Fuv(U+iU,V)>;
#local P3=<U,V+iV,__Fuv(U,V+iV)>;
#local P4=<U,V-iV,__Fuv(U,V-iV)>;
#local B1=P4-P0;
#local B2=P2-P0;
#local B3=P3-P0;
#local B4=P1-P0;
#local N1=vcross(B1,B2);
#local N2=vcross(B2,B3);
#local N3=vcross(B3,B4);
#local N4=vcross(B4,B1);
#local Norm=vnormalize((N1+N2+N3+N4));
#local VecArr[Count]=P0;
#local NormArr[Count]=Norm;
#local UVArr[Count]=<(U-Umin)/dU,(V-Vmin)/dV>;
#local Count=Count+1;
#local J=J+1;
#end
#debug concat("\r Done ", str(Count,0,0)," vertices : ",str(100
*Count/NumVertices,0,2)," %")
#local I=I+1;
#end
BuildWriteMesh2(VecArr, NormArr, UVArr, Iter_U, Iter_V, FileName)
#end
#end
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