By request, source code for the candle flame from my Tea-Light image in
p.b.i

There are 3 variables in the macro:
Turb - effects how distorted the flame is
Scal - final scaling of the flame, required to maintain media density
LSiz - number of lights (0=off, 1=point, >1=area light)

The RND1 seed is also needed to be declared outside the macro so that if
there more than one flames in a scene, their turbulence is different and
they don't look identical.

Enjoy!!


//START
#declare RND1=seed(2);
#macro Flam (Turb,Scal,LSiz)
  #local OS=rand(RND1)*50;
  #local Flam1 = function(x,y,z)
{pow(pow(pow(3*x,2)+pow(0.8*y-0.2,2)+pow(3*z,2),3)+pow(max(1-sqrt(pow(5*x,2)+pow(y+.5,2)+pow(5*z,2)),0),2))}
  #local Flam2 = function(x,y,z)
{floor(pow(sqrt(pow((3.5*x),2)+pow((0.4*y+0.6),2)+pow((3.5*z),2)),2))}
  #local FlamF = function(x,y,z) {min(max(Flam1(x,y,z),Flam2(x,y,z)),1)}
  #macro turb_translate (tTurb,tOcta,tLamb,tOmeg,P0,Acc)
    #local PC=P0;
    #local Dir=<0,0,0>;
    #local V0=vlength(vturbulence(tLamb, tOmeg, tOcta, P0)*tTurb);
    #local Step=V0/2;
    #macro AB(PC,Step,d,Dir,V0)
      #local P1=PC+Step*d;
      #local V1=vlength(P1+vturbulence(tLamb, tOmeg, tOcta, P1)*tTurb-P0);
      #if (V1<V0 | d.x=1)
        #local Dir=d;
        #local V0=V1;
      #end
    #end
    #while (V0>Acc)
      #local DrP=Dir;
      AB(PC,Step, x,Dir,V0)
      AB(PC,Step,-x,Dir,V0)
      AB(PC,Step, y,Dir,V0)
      AB(PC,Step,-y,Dir,V0)
      AB(PC,Step, z,Dir,V0)
      AB(PC,Step,-z,Dir,V0)
      #if (vlength(DrP+Dir)=0)
        #local Step=Step/2;
      #else
        #local Step=V0/2;
      #end
      #local PC=PC+Step*Dir;
    #end
    PC
  #end
  #local tOcta=7;
  #local tLamb=1.32;
  #local tOmeg=0.35;
  union{
      sphere{0 1.1 scale <1/2,1,1/2> translate y*(0.15+OS)
      hollow
      pigment{rgbt <1,1,1,1>}
      interior{
        media{
          emission rgb 25/Scal
          method 3
          intervals 2
          density{
            function{FlamF(x,y-OS,z)}
            color_map{
              [0.00 rgb <1,1,.5>]
              [0.20 rgb <1,.5,0>]
              [0.60 rgb <1,.1,0>]
              [0.78 rgb <0,0,0>]
              [0.86 rgb <0,0,0>]
              [0.92 rgb <0,0,1>]
              [0.98 rgb <0,0,1>]
              [1.00 rgb <0,0,0>]
            }
            warp{
              turbulence Turb
              octaves tOcta
              lambda tLamb
              omega tOmeg
            }
          }
          #local FlamF2 = function(x,y,z)
{pow(max((1-sqrt(pow(x*2.2,2)+pow(y/1.5,2)+pow(z*2.2,2))),0),3)}
          density{
            function{3*FlamF2(x,y-OS-0.15+0.5,z)}
            warp{
              turbulence Turb
              octaves tOcta
              lambda tLamb
              omega tOmeg
            }
          }
        }
      }
      translate -y*OS
    }
    sphere{0 1
      hollow
      pigment{rgbt <1,1,1,1>}
      interior{
        media{
          emission rgb <0.98824, 0.58039, 0.0451>/Scal
          method 3
          intervals 2
          density{
            function{3/exp(sqrt(pow(x*1.3,2)+pow(y,2)+pow(z*1.3,2))*4)}
          }
        }
      }
      no_shadow
      translate turb_translate(Turb,tOcta,tLamb,tOmeg,y*OS,0.001)
      translate -y*OS
    }
    cylinder{-y*10, y*40, 5
      hollow
      pigment{rgbt <1,1,1,1>}
      interior{
        media{
          absorption rgb 1/Scal
          density{

function{pow(max(1-sqrt(pow(x/2,2)+pow((y-5)/35,2)+pow(z/2,2)),0),0.5)*5}
             scale 1/4
             warp{
              turbulence 0.5
              octaves 4
              lambda 4
              omega 0.5
            }
            scale 4
          }
          density{
            bozo
            colour_map{[0.2 rgb 1.0][0.8 rgb -0.30]}
            scale <1/2,2,1/2>*3
            warp{
              turbulence 0.5
              octaves 4
              lambda 4
              omega 0.5
            }
          }

        }
      }
      translate -y*2
      scale 1/4
      no_image

    }
    #if (LSiz>0)
      light_source{0
        rgb <0.98824, 0.58039, 0.0451>
        #if (LSiz>1)
          area_light x/2 z/2
          LSiz,LSiz
          adaptive 1
          jitter
          circular
          orient
        #end
        media_attenuation on
        fade_power ln(1/(sqrt(2)-1))/ln(2)
        fade_distance 10*Scal
        translate turb_translate(Turb,tOcta,tLamb,tOmeg,y*OS,0.001)
        translate -y*OS
        projected_through{cylinder {0, y*10,1 translate y*(0.15-0.5)}}
      }
    #end
    translate -turb_translate(Turb,tOcta,tLamb,tOmeg,y*(OS-0.5),0.001)
    translate y*OS
    scale <1,1.2,1>
  }
#end
//END

-tgq

Post a reply to this message

This is possibly a dumb question, but how long does it take to render? I've
tried:
Flam (1,2,1)
as a "quick" test, but it's nearing its eleventh parsing hour and still no
render.

Post a reply to this message

"Grassblade" <nomail@nomail> wrote:
> This is possibly a dumb question, but how long does it take to render? I've
> tried:
> Flam (1,2,1)
> as a "quick" test, but it's nearing its eleventh parsing hour and still no
> render.

Hmm shouldn't take that long.  One thing is don't set the turbulence (1st
parameter too high, usually 0.2 or less will suffice.  The flame macro has
a macro in it to backtrack the turbulence to keep the flame center at the
right location.  If turbulence is too high, it can get stuck trying to do
this.
Try Flam(0.2,2,1) and let me know if that works.

-tgq

Post a reply to this message

"Trevor G Quayle" <Tin### [at] hotmailcom> wrote:
> Try Flam(0.2,2,1) and let me know if that works.
>
> -tgq
Oh, my mistake. Works a treat. ^_^ I have made some tests, and parse is
instantaneous up to turb=0.693. After that it must get stuck in a loop.
There's no real need to go that high though, as the flame is quite bent
over at 0.5 already.

Post a reply to this message