![](/i/fill.gif) |
![](/i/fill.gif) |
|
![](/i/fill.gif) |
|
![](/i/fill.gif) |
| ![](/i/fill.gif) |
| ![](/i/fill.gif) |
|
![](/i/fill.gif) |
|
![](/i/fill.gif) |
| ![](/i/fill.gif) |
| ![](/i/fill.gif) |
|
![](/i/fill.gif) |
Put this together using Jaime's hf2iso.pov and a custom compile of pov in
which I altered the media code. Unfortunately the isosurface and media
didn't play well together, so I wound up killing the settings of the
isosurface in order to get it to render. Took 10 hours 30 minutes to render
this which is way too long.
Mike
Post a reply to this message
Attachments:
Download 'rainbowmedia.jpg' (103 KB)
Preview of image 'rainbowmedia.jpg'
![rainbowmedia.jpg](/povray.binaries.images/attachment/%3C4943f46e%40news.povray.org%3E/rainbowmedia.jpg?ttop=443866&toff=2950&preview=1)
|
![](/i/fill.gif) |
| ![](/i/fill.gif) |
| ![](/i/fill.gif) |
|
![](/i/fill.gif) |
|
![](/i/fill.gif) |
| ![](/i/fill.gif) |
| ![](/i/fill.gif) |
|
![](/i/fill.gif) |
Wasn't it Mike Hough who wrote:
>Put this together using Jaime's hf2iso.pov and a custom compile of pov in
>which I altered the media code. Unfortunately the isosurface and media
>didn't play well together, so I wound up killing the settings of the
>isosurface in order to get it to render. Took 10 hours 30 minutes to render
>this which is way too long.
I notice two tiny errors.
1: Because of the way that bows are created, they always appear
perfectly perpendicular to the line of sight, so you never get a
perspective effect like that.
2: The gap between the two bows is way too narrow.
On the up side, I see that you did include the Alexander's Band. Most
people who depict rainbows don't bother with that.
--
Mike Williams
Gentleman of Leisure
Post a reply to this message
|
![](/i/fill.gif) |
| ![](/i/fill.gif) |
| ![](/i/fill.gif) |
|
![](/i/fill.gif) |
|
![](/i/fill.gif) |
| ![](/i/fill.gif) |
| ![](/i/fill.gif) |
|
![](/i/fill.gif) |
The first error is probably due to the way I am calculating the angle
between the camera and the light directions. Will see if I can make it more
accurate
The second error is probably from reducing the angle for the second bow so
that it would fit in the view during testing.
thanks for the feedback,
Mike
"Mike Williams" <nos### [at] econym demon co uk> wrote in message
news:HME### [at] econym demon co uk...
> Wasn't it Mike Hough who wrote:
>>Put this together using Jaime's hf2iso.pov and a custom compile of pov in
>>which I altered the media code. Unfortunately the isosurface and media
>>didn't play well together, so I wound up killing the settings of the
>>isosurface in order to get it to render. Took 10 hours 30 minutes to
>>render
>>this which is way too long.
>
> I notice two tiny errors.
>
> 1: Because of the way that bows are created, they always appear perfectly
> perpendicular to the line of sight, so you never get a perspective effect
> like that.
>
> 2: The gap between the two bows is way too narrow.
>
> On the up side, I see that you did include the Alexander's Band. Most
> people who depict rainbows don't bother with that.
>
> --
> Mike Williams
> Gentleman of Leisure
Post a reply to this message
|
![](/i/fill.gif) |
| ![](/i/fill.gif) |
| ![](/i/fill.gif) |
|
![](/i/fill.gif) |
|
![](/i/fill.gif) |
| ![](/i/fill.gif) |
| ![](/i/fill.gif) |
|
![](/i/fill.gif) |
"Mike Hough" <nos### [at] nospam com> wrote:
> Put this together using Jaime's hf2iso.pov and a custom compile of pov in
> which I altered the media code. Unfortunately the isosurface and media
> didn't play well together, so I wound up killing the settings of the
> isosurface in order to get it to render. Took 10 hours 30 minutes to render
> this which is way too long.
>
> Mike
You could try to use my rainbow include file. I wrote it some time ago, but
until now, nobody was really interested in it yet. This include file creates a
more physically correct rainbow with eiter POV-Ray's rainbow feature or the
media feature and renders acceptably fast, I guess. Here's the link:
http://news.povray.org/povray.binaries.scene-files/attachment/<web.438d9f95c0a56753b05a49370@news.povray.org>/rainbow.z
ip?ttop=287937&toff=150
Post a reply to this message
|
![](/i/fill.gif) |
| ![](/i/fill.gif) |
| ![](/i/fill.gif) |
|
![](/i/fill.gif) |
|
![](/i/fill.gif) |
| ![](/i/fill.gif) |
| ![](/i/fill.gif) |
|
![](/i/fill.gif) |
"Florian Siegmund" <flo### [at] gmx at> wrote in message
news:web.4945442b619c0ff365a1cfee0@news.povray.org...
> You could try to use my rainbow include file. I wrote it some time ago,
> but
> until now, nobody was really interested in it yet. This include file
> creates a
> more physically correct rainbow with eiter POV-Ray's rainbow feature or
> the
> media feature and renders acceptably fast, I guess. Here's the link:
>
>
http://news.povray.org/povray.binaries.scene-files/attachment/<web.438d9f95c0a56753b05a49370@news.povray.org>/rainbow.z
> ip?ttop=287937&toff=150
>
Your instructions don't seem to say how to get a rainbow to appear. They
just seem to describe the options for tailoring it once you get to see it.
Do you have a simple scene file to serve as an example for getting the
default one to appear?
The include file seems to add a couple of spheres to the scene, but I placed
a camera and a light source at the default location specified in the include
file and got a black screen. I changed the background to white and got a
white screen, so I guess it needs something specific in the scene file to
make the rainbow visible.
BTW. You shouldn't necessarily be discouraged by a lack of feedback. The
POV-Ray object collection has had over 20,000 downloads since it started a
year ago, but there's been very little feedback.
Regards,
Chris B.
Post a reply to this message
|
![](/i/fill.gif) |
| ![](/i/fill.gif) |
| ![](/i/fill.gif) |
|
![](/i/fill.gif) |
|
![](/i/fill.gif) |
| ![](/i/fill.gif) |
| ![](/i/fill.gif) |
|
![](/i/fill.gif) |
Was going to ask the same. If a scene file is provided I can test it out and
see how it compares speed-wise.
Mike
"Chris B" <nom### [at] nomail com> wrote in message
news:49457d36$1@news.povray.org...
>
> "Florian Siegmund" <flo### [at] gmx at> wrote in message
> news:web.4945442b619c0ff365a1cfee0@news.povray.org...
>> You could try to use my rainbow include file. I wrote it some time ago,
>> but
>> until now, nobody was really interested in it yet. This include file
>> creates a
>> more physically correct rainbow with eiter POV-Ray's rainbow feature or
>> the
>> media feature and renders acceptably fast, I guess. Here's the link:
>>
>>
http://news.povray.org/povray.binaries.scene-files/attachment/<web.438d9f95c0a56753b05a49370@news.povray.org>/rainbow.z
>> ip?ttop=287937&toff=150
>>
>
> Your instructions don't seem to say how to get a rainbow to appear. They
> just seem to describe the options for tailoring it once you get to see it.
> Do you have a simple scene file to serve as an example for getting the
> default one to appear?
>
> The include file seems to add a couple of spheres to the scene, but I
> placed a camera and a light source at the default location specified in
> the include file and got a black screen. I changed the background to white
> and got a white screen, so I guess it needs something specific in the
> scene file to make the rainbow visible.
>
> BTW. You shouldn't necessarily be discouraged by a lack of feedback. The
> POV-Ray object collection has had over 20,000 downloads since it started a
> year ago, but there's been very little feedback.
>
> Regards,
> Chris B.
Post a reply to this message
|
![](/i/fill.gif) |
| ![](/i/fill.gif) |
| ![](/i/fill.gif) |
|
![](/i/fill.gif) |
|
![](/i/fill.gif) |
| ![](/i/fill.gif) |
| ![](/i/fill.gif) |
|
![](/i/fill.gif) |
"Chris B" <nom### [at] nomail com> wrote:
> Your instructions don't seem to say how to get a rainbow to appear. They
> just seem to describe the options for tailoring it once you get to see it.
> Do you have a simple scene file to serve as an example for getting the
> default one to appear?
>
> The include file seems to add a couple of spheres to the scene, but I placed
> a camera and a light source at the default location specified in the include
> file and got a black screen. I changed the background to white and got a
> white screen, so I guess it needs something specific in the scene file to
> make the rainbow visible.
>
> BTW. You shouldn't necessarily be discouraged by a lack of feedback. The
> POV-Ray object collection has had over 20,000 downloads since it started a
> year ago, but there's been very little feedback.
>
> Regards,
> Chris B.
Sorry, that was my fault. Here's a simple scene file with nothing but a plane,
light and the rainbow. Don't bother when the scene takes some time to parse.
This is because the include file is nothing else than a 'rainbow raytracer'
which is calculating the reflection, rafraction and dispersion of light rays in
a water droplet. The couple of spheres you mentioned is just the container
object for the media. Don't bother your head about this :)
So here's a little bit of code for you:
// only the following two identifiers declared before including
// the "rainbow.inc" file are really necessary to see the rainbow
#declare camera_location = <0, 3, 0>;
#declare rb_light_location = <500, 50, -500>;
#declare rb_light_c = rgb <1, 1, 1>; // a color to be multiplied
// with the rainbow color bands
// (color of the virtual light source which is casting the rainbow)
camera {
location camera_location // this setting is obligatory for getting
// a correct result
look_at <0, 3, 1>
angle 30
}
light_source {rb_light_location color rb_light_c} // not really necessary,
// because the rainbow media is emitting, not scattering
plane {y, 0 pigment {color rgb 1}}
background {color rgb <0.01, 0.05, 0.15>}
// the following lines are just for playing around with and testing speed and
// quality of the resulting image
#declare secondary_rb = on;
#declare rb_distance = 40;
#declare rb_brightness = 0.75;
#declare rb_type = 2; // slower but more accurate than type 1
// (type 1 is very good for testing purposes, because it renders really fast!)
#declare rb_spectrum_samples = 50; // number of samples in the wave spectrum
#declare rb_intervals = 20; // number of color maps put together
// to create the rainbow
#declare rb_c_map_samples = 80; // samples in a single color map
#declare rb_area_light_angle = 0.15; // faking an area light source for
// obtaining a smooth rainbow
#declare rb_area_light_samples = 10;
#include "rainbow.inc"
Post a reply to this message
|
![](/i/fill.gif) |
| ![](/i/fill.gif) |
| ![](/i/fill.gif) |
|
![](/i/fill.gif) |
|
![](/i/fill.gif) |
| ![](/i/fill.gif) |
| ![](/i/fill.gif) |
|
![](/i/fill.gif) |
"Florian Siegmund" <flo### [at] gmx at> schreef in bericht
news:web.4945442b619c0ff365a1cfee0@news.povray.org...
> You could try to use my rainbow include file. I wrote it some time ago,
> but
> until now, nobody was really interested in it yet. This include file
> creates a
> more physically correct rainbow with eiter POV-Ray's rainbow feature or
> the
> media feature and renders acceptably fast, I guess. Here's the link:
>
>
http://news.povray.org/povray.binaries.scene-files/attachment/<web.438d9f95c0a56753b05a49370@news.povray.org>/rainbow.z
> ip?ttop=287937&toff=150
>
I have had it on my list for testing for a long time.... :-)
Thomas
Post a reply to this message
|
![](/i/fill.gif) |
| ![](/i/fill.gif) |
| ![](/i/fill.gif) |
|
![](/i/fill.gif) |
|
![](/i/fill.gif) |
| ![](/i/fill.gif) |
| ![](/i/fill.gif) |
|
![](/i/fill.gif) |
I have done a few test renders with your include file. Your model appears
more accurate than mine, as I just threw the colors in at regular intervals.
Rendering took about 10 times longer to render than my method using the
scene provided, which is probably because I made the changes internally
rather than in SDL. My changes were to scattering rather than emission
media, which increases the render times many times when there is complex
geometry in the scene due to shadow tests, but is relatively fast without
many objects in the scene.
Mike
"Florian Siegmund" <flo### [at] gmx at> wrote in message
news:web.49459cdf619c0ff365a1cfee0@news.povray.org...
> "Chris B" <nom### [at] nomail com> wrote:
>> Your instructions don't seem to say how to get a rainbow to appear. They
>> just seem to describe the options for tailoring it once you get to see
>> it.
>> Do you have a simple scene file to serve as an example for getting the
>> default one to appear?
>>
>> The include file seems to add a couple of spheres to the scene, but I
>> placed
>> a camera and a light source at the default location specified in the
>> include
>> file and got a black screen. I changed the background to white and got a
>> white screen, so I guess it needs something specific in the scene file to
>> make the rainbow visible.
>>
>> BTW. You shouldn't necessarily be discouraged by a lack of feedback. The
>> POV-Ray object collection has had over 20,000 downloads since it started
>> a
>> year ago, but there's been very little feedback.
>>
>> Regards,
>> Chris B.
>
> Sorry, that was my fault. Here's a simple scene file with nothing but a
> plane,
> light and the rainbow. Don't bother when the scene takes some time to
> parse.
> This is because the include file is nothing else than a 'rainbow
> raytracer'
> which is calculating the reflection, rafraction and dispersion of light
> rays in
> a water droplet. The couple of spheres you mentioned is just the container
> object for the media. Don't bother your head about this :)
>
> So here's a little bit of code for you:
>
> // only the following two identifiers declared before including
> // the "rainbow.inc" file are really necessary to see the rainbow
> #declare camera_location = <0, 3, 0>;
> #declare rb_light_location = <500, 50, -500>;
>
> #declare rb_light_c = rgb <1, 1, 1>; // a color to be multiplied
> // with the rainbow color bands
> // (color of the virtual light source which is casting the rainbow)
>
> camera {
> location camera_location // this setting is obligatory for getting
> // a correct result
> look_at <0, 3, 1>
> angle 30
> }
>
> light_source {rb_light_location color rb_light_c} // not really
> necessary,
> // because the rainbow media is emitting, not scattering
>
> plane {y, 0 pigment {color rgb 1}}
>
> background {color rgb <0.01, 0.05, 0.15>}
>
> // the following lines are just for playing around with and testing speed
> and
> // quality of the resulting image
> #declare secondary_rb = on;
> #declare rb_distance = 40;
> #declare rb_brightness = 0.75;
> #declare rb_type = 2; // slower but more accurate than type 1
> // (type 1 is very good for testing purposes, because it renders really
> fast!)
> #declare rb_spectrum_samples = 50; // number of samples in the wave
> spectrum
> #declare rb_intervals = 20; // number of color maps put together
> // to create the rainbow
> #declare rb_c_map_samples = 80; // samples in a single color map
> #declare rb_area_light_angle = 0.15; // faking an area light source for
> // obtaining a smooth rainbow
> #declare rb_area_light_samples = 10;
>
> #include "rainbow.inc"
>
Post a reply to this message
|
![](/i/fill.gif) |
| ![](/i/fill.gif) |
| ![](/i/fill.gif) |
|
![](/i/fill.gif) |
|
![](/i/fill.gif) |
| ![](/i/fill.gif) |
| ![](/i/fill.gif) |
|
![](/i/fill.gif) |
> -----Original Message-----
> From: Mike Hough [mailto:nos### [at] nospam com]
> Took 10 hours 30 minutes to render this which is way too long.
Kids!
I remember when you could render a few simple spheres, and use the
pixels appearing on screen as a rather accurate stopwatch!
And a render isn't slow unless it won't finish until after your next
birthday :)
(Hmm... I think I'll use that as my new sig!)
...Ben Chambers
www.pacificwebguy.com
A render isn't slow unless it won't finish until after your next
birthday.
Post a reply to this message
|
![](/i/fill.gif) |
| ![](/i/fill.gif) |
| ![](/i/fill.gif) |
|
![](/i/fill.gif) |
|
![](/i/fill.gif) |
| ![](/i/fill.gif) |
|
![](/i/fill.gif) |