Hi(gh)!

Am 29.12.2017 um 16:42 schrieb clipka:
> 
> Absolutely. Everything you can use in a pigment, eval_pigment() will
> handle correctly - for technically feasible definitions of "correctly".

Obviously not, at least not with POV-Ray for Windows... I used a 16-bit 
PNG generated with Wilbur to be parsed to a spherical mesh2 with this 
script:

// beginning of code

#include "functions.inc"

#declare xx=1024;
#declare yy=512;
#declare minrad=22;
#declare maxrad=38;


#declare AsteroidRelief =
pigment
{
   image_map { tga "asteroid1.tga" }
}

#declare vertices=2+xx*(yy-2);

#fopen asteroid_mesh_inc "asteroid_mesh.inc" write
#write (asteroid_mesh_inc,
         "#declare asteroid_mesh =\n
         mesh2\n
         {\n
           vertex_vectors\n
           {\n",
             vertices,"\n",
             <0, -35.678431, 0>," // south pole \n") // number of 
vertices: 2+b*(a-2) [2+xx*(yy-2)]
#declare a=1;
#while (a<yy-1)
   #declare b=0;
   // #declare rdcum = 0;
   #while (b<xx)
     #declare redval=eval_pigment(AsteroidRelief, <(0.5+b)*(1/xx), 
(0.5+a)*(1/yy), 0>).red * (maxrad-minrad);
     #declare greenval=eval_pigment(AsteroidRelief, <(0.5+b)*(1/xx), 
(0.5+a)*(1/yy), 0>).green * ((maxrad-minrad)/255);
     #declare rd=minrad+redval+greenval;
     /* #if (a=1 | a=yy-2)
       #declare rdcum=rdcum+rd;
     #end */
     #write (asteroid_mesh_inc,
 
(rd*<sin(radians(b*(360/xx)))*cos(radians(-90+a*(180/(yy-2)))), 
sin(radians(-90+a*(180/(yy-2)))), 
cos(radians(b*(360/xx)))*cos(radians(-90+a*(180/(yy-2))))>)," // ",rd,"\n")
     #declare b=b+1;
   #end
   #declare a=a+1;
#end

#write (asteroid_mesh_inc, <0, 35.741176, 0>,"// north pole\n
                         }\n
                         face_indices\n
                         {\n",
                            xx*2+xx*2*(yy-3),"\n") // number of faces: 
b*2+b*2*(a-3) [xx*2+xx*2*(yy-3)]
#declare a=0;
#while (a<yy-1)
   #declare b=0;
   #while (b<xx)
     #switch (a)
       #case (0)
         #if (b < xx-1)
           #write (asteroid_mesh_inc, <0, a+1+b, a+1+mod(b+1,xx)>, "\n") 
// b faces, all sharing first vertex (#0)
         #else
           #write (asteroid_mesh_inc, <0, a+1+b, 1>, "\n" // last 
triangle connecting to first one
         #end
       #break
       #range (1, yy-3)
         #if (b < xx-1)
           #write (asteroid_mesh_inc, <1+(a-1)*xx+b, 
1+(a-1)*xx+mod(b+1,xx), 1+a*xx+b>,",",<1+a*xx+b, 1+a*xx+mod(b+1,xx), 
1+(a-1)*xx+mod(b+1,xx)>, "\n") // b*2*(a-3) faces
         #else
           #write (asteroid_mesh_inc, <1+(a-1)*xx+b, 1+(a-1)*xx, 
1+a*xx+b>,",",<1+a*xx+b, 1+(a-1)*xx, 1+a*xx>, "\n") // last pair of 
triangles in row connecting to first pair
         #end
       #break
       #case (yy-2)
         #if (b < xx-1)
           #write (asteroid_mesh_inc,  <1+(a-1)*xx+b, 
1+(a-1)*xx+mod(b+1,xx), vertices-1>) // b faces, all sharing last vertex
         #else
           #write (asteroid_mesh_inc,  <1+(a-1)*xx+b, 1+(a-1)*xx, 
vertices-1> // last triangle connecting to first one
         #end
       #break
     #end
     #declare b=b+1;
   #end
   #declare a=a+1;
#end
#write (asteroid_mesh_inc, "  }\n}")

#fclose asteroid_mesh_inc

// end of code

It seemed to parse correctly - but POV-Ray crashed immediately 
afterwards, regardless how big or small values I used for xx and yy. I 
didn't try yet whether it still produced a valid mesh2 - but I don't 
think so.

See you in Khyberspace!

Yadgar

Post a reply to this message