User:Le Forgeron/UVMapping

• Everything about HgPovray38 in User:Le_Forgeron/HgPovray38
• Code is available on branch hgpovray38 at https://github.com/LeForgeron/povray

UV mapping of shapes

The origin of the mapping for u=0 (at v=0) can be controlled by adding uv_reference <vector>, to define with the axis of symmetry a half-plane in which the origin is to be found.

So far the addition, when compared to official master, covers:

• cone
• cylinder
• lemon
  • first point is at v=0
  • second point is at v=1
  • outer first disc is at v=1/4
  • outer second disc is at v=3/4
• disc
  • inner circle is at v=0
  • outer circle is at v=1
• sphere_sweep
  • the first segment is the axis of symmetry for the purpose of uv_reference
  • the first sphere is at v=0
  • the last sphere is at v=1
  • the progression of v is proportional to the length of the segment, when compared to the cumulated length of all segments
  • v is constant on each sphere, and u transfers to the next segment

#version 3.7;
global_settings { assumed_gamma 1.0 }
camera
{ orthographic
  location - 30 * z
  direction z
  up y
  right image_width* x / image_height
  angle 30
}

light_source { -40 * z, 1 }

#declare Angle=-25*z;
#include "colors.inc"
#include "golds.inc"
#include "metals.inc"

#declare Hori=24;
#declare Hori2=8;
#declare Verti=12;
#declare VS=4;
#declare HS=4;
#declare HO=2;
#declare Trans = transform{ scale 2  rotate 65*y rotate 25*x };
#declare Texture1s= texture { uv_mapping  checker texture { pigment { Black } }, texture { pigment {Gray50}}  scale <1/Hori,1/Verti,1> rotate Angle }
#declare Texture1e= texture { uv_mapping  checker texture { pigment { Gray20 }}, texture { pigment {Gray80}}  scale <1/Hori,1/Verti,1> rotate Angle }
#declare T2s0=texture{ pigment { Green } };
#declare T2s0e=texture{ pigment { Cyan } };
#declare T2s1=texture{ pigment { NavyBlue } };
#declare Texture2s= texture
{
  uv_mapping
  gradient x texture_map
  {
    [0 T2s0]
    [1 T2s1]
  }
  //scale <1/Hori,1/Verti,1>
}
#declare Texture2e= texture { uv_mapping
  gradient x texture_map
  {
    [0 T2s0e]
    [1 T2s1]
  }
  //scale <1/Hori,1/Verti,1>
}
#declare Texture3s= texture { uv_mapping  checker texture { pigment { Black } }, texture { pigment {Yellow}}  scale <1/Hori2,1/Verti,1> }
#declare Texture3e= texture { uv_mapping  checker texture { pigment{Gray80} }, texture { pigment {Cyan}}  scale <1/Hori2,1/Verti,1> }
//
#declare Verso = texture
{
  uv_mapping gradient y texture_map
  {
    [0.0 Texture2e ]
    [0.25 Texture2s ]
    [0.25 Texture1s ]
    [0.75 Texture1e ]
    [0.75 Texture3e ]
    [1.00 Texture3s ]
  }
}

#declare Fin=finish {ambient 1 diffuse 0};

#declare Texture1sf= texture { checker texture { pigment { Black } finish{ Fin }}, texture { pigment {Gray50}finish{ Fin}}  scale <1/Hori,1/Verti,1>
}
#declare Texture1ef= texture { checker texture { pigment { Gray20}finish{ Fin}}, texture { pigment {Gray80}finish{ Fin}}  scale <1/Hori,1/Verti,1>
}
#declare T2s0=texture{ pigment { Green }finish{ Fin} };
#declare T2s0e=texture{ pigment { Cyan }finish{ Fin} };
#declare T2s1=texture{ pigment { NavyBlue }finish{ Fin} };
#declare Texture2sf= texture { gradient x texture_map{
    [0 T2s0]
    [1 T2s1]
  }
  //scale <1/Hori,1/Verti,1>
}
#declare Texture2ef= texture { gradient x texture_map{
    [0 T2s0e]
    [1 T2s1]
  }
  //scale <1/Hori,1/Verti,1>
}

#declare Texture3sf= texture { checker texture { pigment { Black }finish{ Fin} }, texture { pigment {Yellow}finish{ Fin}}  scale <1/Hori2,1/Verti,1>
}
#declare Texture3ef= texture { checker texture { pigment{Gray80} finish{ Fin}}, texture { pigment {Cyan}finish{ Fin}}  scale <1/Hori2,1/Verti,1>
}

#declare Flat = texture { gradient y texture_map{
    [0.0 Texture2ef ]
    [0.25 Texture2sf ]
    [0.25 Texture1sf rotate Angle ]
    [0.75 Texture1ef rotate Angle ]
    [0.75 Texture3ef ]
    [1.00 Texture3sf ]
  }
}


cone { -y * 0.5, 0.5, 0.5 * y, 0.25  uv_reference x texture { Verso } transform{ Trans }  translate VS* y + HS * x-HO*x }
cylinder { -y * 0.5, 0.5 * y, 0.5 uv_reference x  texture { Verso } transform { Trans } translate HS * x -HO*x}
lemon
{
  -0.5 * y, .5, 0.5 * y, .25, 1.5 uv_reference x texture
  {
    Verso
  } transform { Trans } translate - VS* y + HS * x
-HO*x}
ovus { 0.5, 0.25 distance 1 radius 2.5 texture { Verso }  transform { Trans } translate - VS * y-HO*x}
disc { 0, -y, 1, 0.125 uv_reference x texture { Verso } transform { Trans } translate +VS*y-HO*x }
//
sphere { 0, 0.5 texture { Verso }  transform { Trans}  translate - VS* y - HS * x-HO*x}
torus { 0.65, 0.25 texture { Verso }  transform { Trans } translate - HS * x-HO*x}
box{ -0.5, 0.5  texture { Verso } transform { Trans }  translate VS* y - HS * x-HO*x }
//
sphere_sweep{ cubic_spline 5 , 
  0, .5, 
  1*y,0.35 
  2*y,0.5 
  3*y,0.35 
  4*y,0.5 
  uv_reference x texture { Verso } transform { Trans } translate -VS*y+2*HS*x-HO*x}

box { 0, <1, 1, 0> texture { Flat }  scale 3 translate - 3/2 * x - y -HO*x}