Difference between revisions of "Reference:Lemon"

Latest revision as of 10:35, 26 June 2017

New to version 3.8 the lemon object has been added. It is similar to the cone in that it's basically described the same way but with these differences:

end points are connected along their axis via the revolution surface that's generated by the circular arc of the Inner_Radius
for the minimal value of Inner_Radius the surface is a spherical segment where the center of the arc lies along the end points axis
with larger values for Inner_Radius the surface is the inner part of a self intersecting torus or frustum
if the given Inner_Radius is too small the minimal value is used instead and a warning is issued
both or either of the end points radii can be zero

example lemon objects

Note: The minimal Inner_Radius value is defined as: sqrt ( Radius² + ( DistanceBetweenEndPoints/2 )² )

The syntax is as follows:

lemon { 
    <Base_Point>, Base_Radius, <Cap_Point>, Cap_Radius, Inner_Radius
    [LEMON_MODIFIERS]
  }

LEMON_MODIFIERS:
  sturm | open | OBJECT_MODIFIER

The following example produced the above image:

#version 3.8;
global_settings { assumed_gamma 1.0 }

camera {
  location -560*z
  direction z
  up y
  rotate x*20
  right image_width*x/image_height
  angle 5
  }

#include "colors.inc"

#macro LightSource (LightColor)
  light_source { <0,0,-200>, LightColor area_light x*15, z*15 20,20 adaptive 1 jitter orient circular }
#end

background { White }
plane { y,-20 pigment { White } }

object { LightSource (1.0) rotate x*40 }
object { LightSource (0.8) rotate x*-40 rotate y*330 }
object { LightSource (1.2) rotate x*80 rotate y*210 }

lemon { <0,-20,0>, 0, <0,20,0>, 0, 30
  texture { pigment { color srgb <1,0,0> }}
  translate x*-12
  sturm
  }
  
lemon { <0,0,0>, 5, <0,-20,0>, 0, 15
  texture { pigment { color srgb <0,1,0> }}
  translate y*10
  translate <3,-10,-10>
  sturm
  }
  
lemon { <0,0,0>, 5, <0,-20,0>, 5, 15
  open
  texture { pigment { color srgb <0,0,1> }}
  interior_texture { pigment { srgb <1,1,0> }}
  translate y*10
  translate <12,2,12>
  sturm
  }

If additional accuracy is required you can add the sturm object modifier.

@@ Line 4: / Line 4: @@
 <tr>
    <td>
-     <p>{{New}} to version 3.7.1 the <code>lemon</code> object has been added. It is similar to the <code>cone</code> in that it's basically described the same way but with these differences:</p>
+     <p>{{New}} to version 3.8 the <code>lemon</code> object has been added. It is similar to the <code>cone</code> in that it's basically described the same way but with these differences:</p>
      <ul>
-       <li>end points are connected by a spherically curved <em>Inner_Radius</em></li>
+       <li>end points are connected along their axis via the revolution surface that's generated by the circular arc of the <em>Inner_Radius</em></li>
-       <li>generally speaking <em>Inner_Radius</em> <strong>must be</strong> greater than or equal to the half distance between end points</li>
+       <li>for the minimal value of <em>Inner_Radius</em> the surface is a spherical segment where the center of the arc lies along the end points axis</li>
-       <li>minimal <em>Inner_Radius</em> is defined as sqrt (radius<sup>2</sup> + (distance/2)<sup>2</sup>)</li>
+       <li>with larger values for <em>Inner_Radius</em> the surface is the inner part of a self intersecting torus or [https://en.wikipedia.org/wiki/Frustum frustum]</li>
-       <li>if the given <em>Inner_Radius</em> is too small the minimal value as defined above is used instead and a warning is issued</li>
+       <li>if the given <em>Inner_Radius</em> is too small the minimal value is used instead and a warning is issued</li>
        <li><em>both</em> or <em>either</em> of the end points radii can be zero</li>
-      <li>coded constraints on minimal <em>Inner_Radius</em> and when end points radii are different can have adverse consequences</li>
      </ul>
    </td>
    <td>
-     [[Image:LeForgeronLemon.png|center|240px<!--centered--->]]
+     [[Image:RefImgLemon.png|center|220px<!--centered--->]]
    </td>
 </tr>
@@ Line 26: / Line 25: @@
 </tr>
 </table>
+<p class="Note"><strong>Note:</strong> The minimal <em>Inner_Radius</em> value is defined as: sqrt ( Radius<sup>2</sup> + ( DistanceBetweenEndPoints/2 )<sup>2</sup> )</p>
 <p>The syntax is as follows:</p>
 <pre>
 lemon {
-     <Base_Point>, Base_Radius, <Cap_Point>, Cap_Radius, Inner_Radius
+     &lt;Base_Point&gt;, Base_Radius, &lt;Cap_Point&gt;, Cap_Radius, Inner_Radius
      [LEMON_MODIFIERS]
    }
@@ Line 40: / Line 40: @@
 <p>The following example produced the above image:</p>
 <pre>
-#version 3.7.1;
+#version 3.8;
 global_settings { assumed_gamma 1.0 }
-camera { location -560*z
+camera {
-         direction z
+  location -560*z
-         up y
+  direction z
-         right image_width*x/image_height
+  up y
-         angle 5
+  rotate x*20
-       }
+  right image_width*x/image_height
+  angle 5
+  }
 #include "colors.inc"
-lemon { -18*y-10*x, 0, 18*y-10*x, 0, 30 texture { pigment { color CH2RGB(30) filter 0.45 } } }
+#macro LightSource (LightColor)
-lemon { +10*x+1*y, 5, 18*y+10*x, 0, 15 texture { pigment { color CH2RGB(100) filter 0.45 } } }
+  light_source { <0,0,-200>, LightColor area_light x*15, z*15 20,20 adaptive 1 jitter orient circular }
-lemon { -1*y+10*x, 5, -18*y+10*x, 5, 15 texture { pigment { color CH2RGB(150) filter 0.45 } } }
+#end
-box { 10*z-20*x-20*y, 10*z+20*x+20*y texture { pigment { color White }}}
+background { White }
+plane { y,-20 pigment { White } }
-light_source { 10*<0,0,-20>, 0.9 }
+object { LightSource (1.0) rotate x*40 }
-light_source { 10*<-5,10,-50>, 0.9 }
+object { LightSource (0.8) rotate x*-40 rotate y*330 }
-light_source { 10*<-10,10,-50>, 0.9 }
+object { LightSource (1.2) rotate x*80 rotate y*210 }
-light_source { 10*<5,10,-50>, 0.9 }
-light_source { 10*<10,10,-50>, 0.9 }
+lemon { <0,-20,0>, 0, <0,20,0>, 0, 30
+  texture { pigment { color srgb <1,0,0> }}
+  translate x*-12
+  sturm
+  }
+lemon { <0,0,0>, 5, <0,-20,0>, 0, 15
+  texture { pigment { color srgb <0,1,0> }}
+  translate y*10
+  translate <3,-10,-10>
+  sturm
+  }
+lemon { <0,0,0>, 5, <0,-20,0>, 5, 15
+  open
+  texture { pigment { color srgb <0,0,1> }}
+  interior_texture { pigment { srgb <1,1,0> }}
+  translate y*10
+  translate <12,2,12>
+  sturm
+  }
 </pre>
 <p>If additional accuracy is required you can add the <code>[[Reference:Sturm Object Modifier|sturm]]</code> object modifier.</p>
 <p>See also the <code>[[Reference:Cone|cone]]</code> object.</p>

Difference between revisions of "Reference:Lemon"

Latest revision as of 10:35, 26 June 2017

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