File:Moon rotating thirdquarter 220px.gif

Moon_rotating_thirdquarter_220px.gif(220 × 220 pixels, file size: 5.5 MB, MIME type: image/gif, looped, 240 frames, 9.6 s)

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Description
English: Animated rotation of the earth's moon. The moon is shown constantly lit from the left (third quarter), like an observer following the earth in its orbit would see it. On earth, only one side is visible, but the moon rotates relatively to the sun during one month. In order to render the animation of a full rotation, images from spacecraft beyond the moon had to be used. At the terminator in the image center, craters can be seen most clearly.
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Date
Source Own work
Author Geek3
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Source Code edit

 
This image was created with POV-Ray.
 
This image was created with ImageMagick.

The frames of the animation were created with POV-Ray, a free 3D rendering program. Two components are required:

  • A surface color map, free image from NASA's 1994 Clementine mission.
  • An elevation map (from USGS, public domain) with grey values encoding surface altitudes. The elevation map can be used as a simple bump map for fast rendering, or (as in this case) to reconstruct a full 3D model with realistic shadows.

Executing POV-ray rendering:

povray +H220 +W220 +UA +AM1 +A0.03 +R6 +KI0 +KF1 +KC +KFI1 +KFF240 +Oframe Moon_rotating_thirdquarter_220px.pov

Assembling the gif animation with ImageMagick:

convert -loop 0 -delay 4 -dispose background frame???.png -channel alpha -threshold 50% +channel +dither -colors 256 Moon_thirdquarter_full_220px.gif

Source file Moon_rotating_thirdquarter_220px.pov:

// Moon_rotating_thirdquarter_220px.pov
#version 3.7;
#include "colors.inc"

global_settings { assumed_gamma 1 }

camera { location <0, 0, -220> look_at <0, 0, 0> up 0.00526 right 0.00526 }

light_source {
    <2,0,0> * 200
    color White
    parallel
    point_at <0,0,0>
}

// use true 3D surface
#include "functions.inc"
#declare ele=function{
    pigment{
        image_map{
            jpeg "moon_elevation.jpg" map_type 1 interpolate 2
        }
    }
}

#declare rs=0.006; // ratio of roughness to radius
isosurface {
    function { f_sphere(x,y,z, 1) + rs * (1 - ele(x,y,z).gray) }
    contained_by { sphere {0,1.01} }
    accuracy 0.00001
    max_gradient 1.2
    texture {
        pigment {
            image_map { jpeg "moon_surface.jpg" map_type 1 } }
            finish {
                ambient rgb 0.006*<1,1,1> // space is dark
                diffuse 1.9 // brightness
                brilliance 1.0 // seems most realistic
            }
        }
    scale <1,1,-1>
    rotate <0,-90+360*clock,0>
    translate <0,0,0>
}

Licensing edit

I, the copyright holder of this work, hereby publish it under the following licenses:
GNU head Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled GNU Free Documentation License.
w:en:Creative Commons
attribution
This file is licensed under the Creative Commons Attribution 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.
You may select the license of your choice.

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Date/TimeThumbnailDimensionsUserComment
current00:26, 23 March 2016Thumbnail for version as of 00:26, 23 March 2016220 × 220 (5.5 MB)Geek3 (talk | contribs)== {{int:filedesc}} == {{Information |Description ={{en|1=Animated rotation of the earth's moon. The moon is shown constantly lit from the left (third quarter), like an observer following the earth in its orbit would...

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