//Mick's Grass.inc

#declare GrassTex = texture{
    pigment {
    granite
    color_map {
      [0.0 color rgb <0.5, 0.5, 0.2>*3]
      [0.25 color rgb <0.7, 1, 0.2>*2.5]
      [0.5 color rgb <.98,.95,.85>*2]
      [0.75 color rgb 3]
    }
    scale 0.00125
    }
    finish{ambient 0.2 specular .5}
    }
    
#declare R = seed(3243);
 
#declare blade = mesh {//creates a single blade of grass

 #declare No_Segs = 10;
 #declare C = 0;
 #declare Seg_length = .35;
 #declare Rot = 90-(15+(rand(R)*20));//controls the bend of the grass
 #declare Ox = 0;
 #declare Oy =0;
 #declare Nx = Seg_length;
 #declare Ny = Seg_length;
 #declare Z= 0.15;  
  
    #while (C<No_Segs)

                #declare xdist = sin(radians(90-Rot))*Seg_length;
                #declare ydist = cos(radians(90-Rot))*Seg_length;
                   #declare No_Segs = 10+(rand(R)*10); 
                    #declare Nx = Ox+xdist; 
                    #declare Ny = Oy+ydist;
                    
                    
               #if (C<(No_Segs-1))
                 triangle{<Ox,Oy,Z> <Ox,Oy,-Z> <Nx,Ny,Z> }
                 triangle{<Ox,Oy,-Z> <Nx,Ny,Z> <Nx,Ny,-Z>}
               #else
                 triangle{<Ox,Oy,Z> <Ox,Oy,-Z> <Nx,Ny,0>}
               #end           
                  #declare Rot = Rot-pow((rand(R)),2);
                  #declare Ox = Nx;
                  #declare Oy = Ny;
                  
                #declare Z=Z-0.012;
                #declare Seg_length = Seg_length +.01;   
                #declare C=C+1;
    #end
    //translate y*.05
 texture{GrassTex}
}//end mesh    

#declare Hor = -5;
#declare Ver = -5;
  
#declare Patch = union{// creates a patch of grass

    #while (Hor<5)
       #while (Ver<5)
    object{blade rotate y*-((Ver*20)*rand(R)*120)
        scale y *1+rand(R)
        translate<Hor/3,0,Ver/3>
        }
        #declare Ver = Ver +1;
        #end
      #declare Ver= -3;
      #declare Hor = Hor+1;   
    #end               
}//end of union