POV-Ray : Newsgroups : povray.binaries.animations : Solar System : Re: Solar System Server Time
28 Mar 2024 22:13:33 EDT (-0400)
  Re: Solar System  
From: omniverse
Date: 13 May 2017 00:50:00
Message: <web.5916900b4e8509949c5d6c810@news.povray.org>
Stephen <mca### [at] aolcom> wrote:
> On 5/12/2017 5:31 PM, Bald Eagle wrote:
> >
> >>> Still pondering how to rotate the sun faster around the axis than the equator -
> >>> how to procedurally texture that....

Um, well, faster at equator. About 24 and a half days at equator and about 38
days at poles.

I wanted to do that kind of thing for sunspots and Jupiter cloud bands, which
doesn't transition evenly with latitude. Shouldn't be impossible to make
something looking good enough using patterned maps in a gradient y, guess so
anyway.

> >>
> >> You have started me thinking about creating a DF3 animation, of the sun.
> >
> > Excellent!  Inspiration strikes!
> >
>
> Maybe not. I was thinking about converting Blender's particle system
> into a point cloud or something like that but it is not obvious how it
> is done. I'll give it another decade or two to come up with an idea. ;)
>
>
> > Looks like Bob Hughes has taken a stab at that already:
> > http://objects.povworld.org/binaries/sun.pov
> >

That does go way back, very simple really, and obviously doesn't render right
anymore in 3.7 so I tried fixing that.

It was from animation of solar probe idea, with Sun looking intensely bright at
first and dimming to show solar flares. Meant to be something like a lens filter
is being used. No realism of course.

// Persistence of Vision Ray Tracer Scene Description File
// File: SunChange.pov
// Vers: 3.7
// Desc: The Sun, with flares and corona.  Animatable to an extent.
// Date: 2000.8; 2017.36
// Auth: Bob Hughes
// Note: This Sun is not meant to be accurate, just my interpretation.
//       Will look different in Official POV-Ray as opposed to MegaPOV.
//       Scale is initially 1 million miles to 1 POV unit.

#version 3.7;

global_settings {
 assumed_gamma 1
}

// 1000000 will make scale be 1 unit = 1 mile
#declare S=1000000;

// for show
camera
 {
  location <0,0,-2*S>
  angle 50
  look_at  0
}

background {rgb 0}

/* variable for Sun changes (can change this manually: use 0 to 1) */
#declare TimeLapse=1; //clock; // animate using clock here

// variables for Sunlight fading or filtering
#declare EXT=TimeLapse; // extinction, smaller is brighter
#declare Sc=TimeLapse; // emission, smaller is brighter
#declare Si=TimeLapse/2.5; //intensity, smaller number is brighter

union {

/* may want to use other than the "4" below or something else altogether
 be warned the light color changes the media appearance */
light_source
 {
  0, 3-(Si*4)
       // area_light <.432,0,0>, <0,.432,0>, 3, 3 jitter adaptive 1
       // orient circular
        media_interaction on media_attenuation off
 }

// Sun
#declare Space=density {rgb 0}
#declare Corona=
 density {
        radial turbulence .3 frequency 15
         density_map {
                [0 rgb <.125,.5,1.33>/3*.025*(1/S)]
                [1 rgb <.25,.67,1.25>/3*(.033+(Si/5))*(1/S)]
                }
          sine_wave scale <.25,.125,.25>*3 rotate <5,0,5>
          }
#declare Flares=
 density {
        marble phase (.55+(TimeLapse/10)) turbulence 1.6/2 frequency 1.3
         density_map {
                [0 rgb .025*(1/S)]
                [.75 rgb .05*(1/S)]
                [.85 rgb <.5,.33,.25>*(.1+(Si/1.33))*(1/S)]
                [.925 rgb <.5,.33,.25>*(.1+(Si/2))*(1/S)*2]
                [1 rgb <.5,.33,.25>*(.1+(Si/.33))*(1/S)*3]
                }
         triangle_wave scale 0.67 rotate <60,45,100>
         }
#declare Photosphere=
 density {
        bozo phase (TimeLapse/100) turbulence <1,.5,.25>*1.3
         //warp {turbulence <1,.5,.25>*1.3 octaves 2 lambda 1.5 omega 0.5}
         density_map {
                [0 rgb 0]
                [.95 rgb <1.125,1,.9>*(1.3+(Si/3))*(1/S)]
                [1 rgb <1.125,1,.9>*(.9+(Si/6))*(1/S)]
                }
          ramp_wave scale .015
          }
#declare Surface=
 density {
        crackle phase (TimeLapse/50)
         //warp {turbulence <1,.5,.25> octaves 2 lambda 1.25 omega 0.3}
         density_map {
                [.025*TimeLapse rgb .15*(1/S)]
                [.05*(.75+TimeLapse) rgb .3*(1/S)]
                [1 rgb <.75,.5,.33>*(2.5-(Si/1.25))*(1/S)]
                }
          scallop_wave scale .005
          }
#declare Interior=
 density {
        bozo phase (TimeLapse/100) turbulence <1,.5,.25>*.3
         //warp {turbulence <1,.5,.25>*.3 octaves 2 lambda 1 omega 0.2}
         density_map {
                [0 rgb 0]
                [.09 rgb <1.125,1,.9>*(.3+(Si/3))*(1/S)]
                [1 rgb <1.125,1,.9>*(.9+(Si/6))*(1/S)]
                }
          ramp_wave scale .15
          }

/* Sun (diameter is .864 units at the surface, 1 unit = 1 million miles) */
sphere
 {
  0, 1
 pigment {rgbt 1}
  interior {
        media {
   method 3 samples 10,20
         emission <1,.75,.25>*((2-(Si/.25))+(1-Sc))
        // absorption <.33,.5,.67>*(.1+(Si*10))
        scattering {4,<1,.67,.33>*2 extinction (EXT/20)}
       density {
        spherical turbulence <.000125,.00015,.0002>
      density_map {
      [.025 Space] // end of Sun atmosphere
      [.25 Corona] // solar corona
      [.45 Corona] // solar corona inner edge
      [.5 Flares] // solar flares
      [.515 Photosphere] // solar photosphere
      [.5167+(TimeLapse/30) Photosphere] // solar photosphere
      [.568+(TimeLapse/15) Surface] // solar surface
      [.75+(TimeLapse/7.5) Surface] // solar subsurface
      [1 Interior] // solar interior
      }}
        } // media
        media {
   method 3 samples 5,10
         absorption <.33,.5,.67>*(.1+(Si*3))
       // scattering {4,<1,.67,.33>*1.33 extinction (EXT/20)}
       density {
        spherical turbulence <.000125,.00015,.0002>
      density_map {
      [.025 Space] // end of Sun atmosphere
      //[.25 Corona] // solar corona
      //[.45 Corona] // solar corona inner edge
      [.5 Flares] // solar flares
      //[.515 Photosphere] // solar photosphere
      //[.5167+(TimeLapse/30) Photosphere] // solar photosphere
      //[.568+(TimeLapse/15) Surface] // solar surface
      //[.75+(TimeLapse/7.5) Surface] // solar subsurface
      [1 Interior] // solar interior
      }} // density
     } // media
  } // interior
  rotate 5*TimeLapse*y // a little rotation for animation
 hollow
 no_shadow
 } // sphere
  scale S
}  // union


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