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"Bob Hughes" <omniverse charter net> wrote:
> "Dave VanHorn" <mic### [at] gmail com> wrote in message
> news:web.49063d6478db427ea08ed15e0@news.povray.org...
> >
> > The cylinder object gives me a nice looking fire, (complicated)
> > and the chalice object is fine, but the light sources which should be up
> > in the
> > fire object, don't seem to get OUT.
>
>
> Hmmmm. You don't show what your Flame is made of, such as filtered pigment
> or media, but I'm not sure why you aren't seeing any light from the fire. I
> ran a render of what you are trying using my own fire material and other
> than no_shadow preventing shadowing from the fire cylinder I can see the
> light source.
It's a complicated thing, but it's not causing the lights not to get out.
> Your area_light isn't what I've ever used or recall seeing used, having no
> perpendicular axis to make the grid of lights. And yet that doesn't seem to
> be the actual problem you are getting there, if mine rendered the same here.
The docs say you can make it a linear light by doing X1 in one axis.
> Just to be sure, I changed it to be <1,0,0>,<0,2,0>,5,10 so I could see
> everything else wasn't wrong in some way.
> Something to keep in mind about area_light is how it is still like a point
> source when it comes to location and other things unrelated to the shadowing
> it causes. So other than shadows it is like a regular point of light.
Right.. I'm seeing light from it now, but I'm not seeing the softened shadows,
which I should be..
> Also not knowing your Chalice object means it is possible a surface is
> obscuring the light. There might be a clue by how your fire object has a
> bottom slightly above the light_source, perhaps meaning your Chalice has a
> surface at the same place? So remember area_light remains a point-like
> source based on its location and not the grid being created.
It should be, but not completely. That's what I intend.
I thought I'd outsmart it and use a "looks like" to find out where the lights
are, but that just gives one sphere no matter how many lights I specify.
This version is sort of working..
#declare Fire = object { union { cylinder { <0,0.01,0>, <0,3,0>, 1.0 hollow
material { Flame }
translate <-0,0.5,0>
no_shadow
}
object { Chalice rotate <0, 0, 0>
photons { target 1.0
refraction off
reflection on
}
}
light_source { <0,0,0>
// light's position
color rgb 0.250
// light's color
area_light
<0.0, 0.0, 0.0> <0.0, 1.0, 0.0>
// lights spread out across this distance (x * z)
1, 8
// total number of lights in grid (4x*4z = 16 lights)
adaptive 1
// 0,1,2,3...
fade_distance 2
//
fade_power 2
//
translate <0, 2.0, 0>
//
// Good for locating the lights
looks_like {sphere { <0, 0, 0>,
0.25 }}
}
}
}
#declare Chalice = object { union { cone { 1*y, 0.75,
0, 0.0
open
//material { M_Glass }
texture { T_Brass_3E
normal { bumps 0.1 scale
0.05 }
}
}
cone { 1*y, 0.0,
0, 0.75
open
}
}
}
#declare Flame = material { texture { pigment {rgbt 1.00} } // Just plain clear
interior {
//Explosive interior
media { // POV-Ray supports three types of media:
emissive,
// absorbing, and scattering. "emission" is
self-illuminated
// media. it will not cast light on other
objects, but it
// has the appearance of glowing.
"absorption" blocks light
// instead of emits light. absorbing media
casts shadows on
// other objects. "scattering" media is lit
by other
// light sources, and can scatter light. it
is substantially
// slower to render than the other two
types, however, it
// can be used with photons to create
effects like
// visible sunbeams
emission 5.0
absorption 5.5
// LAYER 1
//
// for our first layer, we'll blend the edge
of the sphere
// to transparent. this will make edges less
obvious and help
// hide the fact that the media is contained
inside a sphere.
// we want it to look free-floating, so it's
important to
// disguise the edges
density { spherical
density_map { [0.0 rgb <0.0, 0.0,
0.0>]
[1.0 rgb <1.0, 1.0,
1.0>]
}
}
// LAYER 2
//
// explosions usually have bright centers.
for our second layer,
// we'll give the explosion a "hot" core by
multiplying past
// the 1.0 range in the center... POV-Ray
doesn't support HDRI
// (the MegaPOV build does) but this trick
works nonetheless
density { spherical
density_map { [0.7 rgb <1.0, 1.0,
1.0>]
[1.0 rgb <8.0, 8.0,
8.0>]
}
}
// LAYER 3
//
// now that we've blocked out the general
shape of our media,
// for our third layer we want to get it
looking more cloud-like
// and less like a ball. we'll do that by
adding some soft, low
// frequency turbulence
density { spherical
density_map { [0.00 rgb <0.0, 0.0,
0.0>]
[0.20 rgb <0.5, 0.0,
0.0>]
[0.40 rgb <0.8, 0.4,
0.0>]
[0.85 rgb <0.2, 0.2,
0.6>]
[0.95 rgb <0.1, 0.1,
1.0>]
}
// here's where the magic
happens... a low turbulence setting
// causes our media to take on a
soft, cloud-like shape
warp { turbulence 0.6
lambda 1.5
// low omega values create
soft, blurry results;
// higher values are crisp
and wrinkly
omega 0.50
}
// this warp causes the explosion
to look like the particulate
// is ejecting from the center by
pulling in all of the color
// toward the center... I haven't
tried it, but I bet you
// could do some nifty animations
by adding a clock term to
// one of these values
warp { black_hole <0.0, 0.0, 0.0>,
2.0
strength .95
falloff 2.5
}
}
//
// LAYER 4
//
// explosions have lots of detail, with many
fine swirls and
// eddies. we can simulate this by using a
high-frequency
// turbulence value. again, we'll multiply
past 1.0 to keep
// the explosion "hot"
density { spherical density_map { [0.0 rgb
<0.0, 0.0, 0.0>]
[0.1 rgb
<1.0, 0.0, 0.0> * .75]
[0.2 rgb
<1.0, 0.5, 0.0> * .75]
[0.8 rgb
<1.0, 1.0, 2.0> * 2.5]
}
warp { turbulence 1.5
lambda 2.5
omega 0.55
octaves 7
}
scale .75
warp { black_hole <0.0, 0.0, 0.0>,
2.0
strength .8
falloff 2.0
}
}
// if you find that you have glitches or black
spots in
// your media, try turning up the number of
samples.
// more samples will cause it to render
slower, so don't
// turn it up more than you need to
samples 20
scale <0.500, 2.00, 0.500>
translate <0.0, 1.0, 0.0>
}
}
}
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