File:Midsphere.png

Original file(1,024 × 1,024 pixels, file size: 115 KB, MIME type: image/png)

Commons-logo.svg This is a file from the Wikimedia Commons. The description on its description page there is shown below.
Commons is a freely licensed media file repository. You can help.

Summary

Description
English: The midsphere of a polyhedron. The red circles indicate the points at which a cone, with its apex at a vertex, is tangent to the sphere. Rendered in POV-ray based on a different rendering of the same model from D. Eppstein (2005), Quasiconvex programming, Combinatorial and Computational Geometry, Goodman, Pach, and Welzl, eds., MSRI Publications 52, 2005, pp. 287-331, arXiv:cs.CG/0412046.
Source Own work
Author David Eppstein

Licensing

I, the copyright holder of this work, hereby publish it under the following license:
w:en:Creative Commons
attribution share alike
This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license.
You are free:
  • to share – to copy, distribute and transmit the work
  • to remix – to adapt the work
Under the following conditions:
  • attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
  • share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible license as the original.

POV-ray source code

// Edge-tangent polytope and the sphere of edge tangencies
// David Eppstein, UC Irvine, 21 May 2001, modified 10 April 2011

global_settings {
   assumed_gamma 2.2
   ambient_light <3,3,3>
}

light_source { <-10, 35, -15> color <4,4,4> }

// light_source { <5, -10, -15> color <1.5,1.5,1.5> }

// perp: <5,1,-6> <1,1,1> <7,-11,4>
// perp: <5,2,-2> <0,1,1> <4,-5,5>

#declare p=<1,1,1>/sqrt(3);
#declare q=<7,-11,4>/sqrt(186);
camera {
   location  <5,1,-6>
   look_at   <0.5, 0, 0>
   up -q*0.65
   right p*0.65
   translate <-0.1,0,-0.5>
   rotate <0,-5,0>
}

sphere { <0.0, 0.0, 0.0>, 2
	texture {
		finish {
			specular 1
			roughness 0.002
			ambient 0.1
			diffuse 0.05
			reflection 1
			phong 0.3
			phong_size 60
		}
		pigment { color rgbf<0.2, 0.2, 1.5, 0.7> }
	}
}

#declare P_Surf =
texture {
    finish {
       ambient 0.2
       diffuse 0.2
    }
    pigment { color red 1 green 1 blue 1 }
}

polygon {
    4,
    <0,2,-2>,<0,2,2>,<2,0,1>,<2,0,-1>
    texture { P_Surf }
}

polygon {
    4,
    <0,2,-2>,<0,2,2>,<-2,0,1>,<-2,0,-1>
    texture { P_Surf }
}

polygon {
    4,
    <0,-2,-2>,<0,-2,2>,<2,0,1>,<2,0,-1>
    texture { P_Surf }
}

polygon {
    4,
    <0,-2,-2>,<0,-2,2>,<-2,0,1>,<-2,0,-1>
    texture { P_Surf }
}

polygon {
	3,
	<0,2,2>,<2,0,1>,<0,-2,2>
	texture { P_Surf }
}

polygon {
	3,
	<0,2,-2>,<2,0,-1>,<0,-2,-2>
	texture { P_Surf }
}

polygon {
	3,
	<0,2,2>,<-2,0,1>,<0,-2,2>
	texture { P_Surf }
}

polygon {
	3,
	<0,2,-2>,<-2,0,-1>,<0,-2,-2>
	texture { P_Surf }
}

#declare P_Ring =
texture {
    finish {
       ambient 0.3
       diffuse 0.3
    }
    pigment { color red 1 green 0 blue 0 }
}

torus {
	2/sqrt(2), 0.013
	texture { P_Ring }
	rotate <-45,0,0>
	translate <0,1,-1>
}

torus {
	2/sqrt(2), 0.013
	texture { P_Ring }
	rotate <45,0,0>
	translate <0,1,1>
}

torus {
	2/sqrt(2), 0.013
	texture { P_Ring }
	rotate <-45,0,0>
	translate <0,1,-1>
	rotate <180,0,0>
}

torus {
	2/sqrt(2), 0.013
	texture { P_Ring }
	rotate <45,0,0>
	translate <0,1,1>
	rotate <180,0,0>
}

torus {
	2*sqrt(1/5), 0.013
	texture { P_Ring }
	rotate <90,-asin(2/sqrt(5))*180/pi,0>
	translate <8/5,0,-4/5>
}

torus {
	2*sqrt(1/5), 0.013
	texture { P_Ring }
	rotate <90,asin(2/sqrt(5))*180/pi,0>
	translate <8/5,0,4/5>
}

torus {
	2*sqrt(1/5), 0.013
	texture { P_Ring }
	rotate <90,-asin(2/sqrt(5))*180/pi,0>
	translate <8/5,0,-4/5>
	rotate <180,0,0>
}

torus {
	2*sqrt(1/5), 0.013
	texture { P_Ring }
	rotate <90,asin(2/sqrt(5))*180/pi,0>
	translate <8/5,0,4/5>
	rotate <180,0,0>
}

Captions

Add a one-line explanation of what this file represents

Items portrayed in this file

depicts

117,898 byte

1,024 pixel

1,024 pixel

image/png

75021f8285aff744b7423aa31bf56329e2f4df28

File history

Click on a date/time to view the file as it appeared at that time.

Date/TimeDimensionsUserComment
current12:49, 10 April 20111,024 × 1,024 (115 KB)David Eppstein{{Information |Description ={{en|1=The midsphere of a polyhedron. The red circles indicate the points at which a cone, with its apex at a vertex, is tangent to the sphere. Rendered in POV-ray based on a different rendering of the same

The following page uses this file: