In the last 24 hours, I was thinking that the pov developers did a great
thing, they just chose an unfortunate name.

It's reasonable for someone to hear "Area Lights" and then see that diagram
from the 3.1g manual and make the same mistake as John has. (I did, too).

The armchair quarterback in me says it should have been called
"soft_shadow_option= yes;"  or something like that.

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"ABX" <abx### [at] abxartpl> schreef in bericht
news:acfumu48ldl5qku5cjm1e4govavtovr27g@4ax.com...
> On Fri, 30 Aug 2002 05:35:16 EDT, "Alex" <ale### [at] alphacit> wrote:
> > IT DOESN'T HAVE SUBSURFACE-SCATTERING!!! IT DOESN'T SUPPORT THE METROPOLIS
> > LIGHT TRANSPORT!! IT'S NOT SPECTRAL BASED!!! IT DOESN'T DO SKYDOMES!!!
> > I WANT BSSRDF! I WANT METROPOLIS! I WANT SPECTRAL! I WANT REAL MOTION BLUR!
> > I WANT PHISICALLY CORRECT DYNAMICS! CLOTH! FLUIDS!
> >
> > Now, *that* is fighting talk :)
> Please don't hurt my eyes with caps lock on ;-)

SHIFT HAPPENS
:)

whoops :)

cu!
--
camera{location-z*3}#macro G(b,e)b+(e-b)*(C/50)#end#macro L(b,e,k,l)#local C=0
;#while(C<50)sphere{G(b,e),.1pigment{rgb G(k,l)}finish{ambient 1}}#local C=C+1
;#end#end L(y-x,y,x,x+y)L(y,-x-y,x+y,y)L(-x-y,-y,y,y+z)L(-y,y,y+z,x+y)L(0,x+y,
<.5,1,.5>,x)L(0,x-y,<.5,1,.5>,x)               // ZK http://www.povplace.be.tf

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Hey,

> Yes, those bastards! They added a feature to the software to create
> soft-edged shadows without the massive overhead of massive point light
> arrays! How dare they?
>
> </sarcasm>
>
> No one's holding a gun to your head and forcing you to use area lights.
> If you dislike them that much, don't use them. You have a perfectly
> servicible light array generator.

I'm sorry if you feel the need to resort to aggressive posts, it was never
my intention to get people riled. I am aware that no one is forcing me to
use arealights, but that doesn't mean that I'm not allowed to suggest that
the feature could use some improvement and revision. That is after all the
way in which growth and development occurs, and I would very much like to
see Povray grow and develop in a very positive way.

As I have mentioned in at least two other posts in this thread, I personally
haven't found massive overheads using the point light arrays, and I do
intend to keep using and developing my macro (I'm toying with the idea of
letting the user specify an imagemap to colour each point light, and also
the idea of using eval to work out when a light is inside an object or not -
hello object_lights ;)). I enjoy the area based illumination it provides as
it's primary function, as well as the soft edged shadows it produces as a
side effect.

> Your test scenes were LAUGHABLY SIMPLE.. sufficient to demonstrate a
> technique, but not a good demonstration of the effects of light arrays
> on rendering time for realistically complex scenes. The fact that you
> seem to think otherwise shows your inexperience and ignorance.

I think you misunderstand; the complex test I was talking about (read my
post to Jaime again) is *not* one of the ones I used in the article. Come
on - the article test were just two spheres and two planes, give me a
*little* credit please ;)

The test I was talking about has not been posted anywhere, it was just a
test I did for myself while developing my macro. It involved an 11mb mesh
with variable reflection, and a large red sphere, also with variable
reflection. The were a lot of inter-reflections between the sphere and the
mesh, where each was reflecting each other over and over. 640x480 with 600
point lights, "+r9 +a0.0" and fairly high quality radiosity (count 200,
error_bound 0.5, recursion_limit 3, low_error_factor .5, minimum_reuse 0)
thrown in for good measure. I rendered it on a middle-of-the-road machine, a
600mhz P3 laptop, which was in use during the render. Render completed in
just a little over two and a half days which, given the number of
calculations in the scene, I think was fairly quick, especially considering
the lovely result. I can post the stats and the image if you like.

Now, by complex test, I don't mean a work of art, or anything pretending to
be a "real" scene - by complex I mean very heavy duty in terms of what I was
asking Povray to do. That includes both the scene and settings used for the
render.

I would hope that in future you think about what you write before you call
someone inexperienced and ignorant.

All the best,


John

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news: 3d6fb27b@news.povray.org...
> The test I was talking about has not been posted anywhere, it was just a
> test I did for myself while developing my macro. It involved an 11mb mesh
> with variable reflection, and a large red sphere, also with variable
> reflection.

While the combination of reflection and radiosity explains much of the
render time, a scene containing 2 of the simplest, fastest-rendering objects
(*) in POV-Ray hardly qualifies as a good scene to test lighting issues,
particularly with regard to the speed issue, which is a fundamental factor
here.
I suggest that you test your solution (if you haven't done so yet - I may
not have read all the posts in this thread) on the benchmark scene, which
uses area_lights, and report the results here.

G.

 (*) unless your mesh textures involves transparency and superposed layers
of polys, like some Poser hair

--
**********************
http://www.oyonale.com
**********************
- Graphic experiments
- POV-Ray and Poser computer images
- Posters

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John Mellerick wrote:
> 
> I'm sorry if you feel the need to resort to aggressive posts...

I haven't, yet.

> I am aware that no one is forcing me to
> use arealights, but that doesn't mean that I'm not allowed to suggest that
> the feature could use some improvement and revision.

And if you have any practical suggestions, then by all means, present 
them. So far, all I've seen out of you is some tests demonstrating that 
when rendering time and memory are no object, an array of point lights 
does a better job of simulating a diffuse light source than a feature 
with no purpose other than making soft shadows.. something which I think 
most of us already knew.

> Come on - the article test were just two spheres and two planes, give me a
> *little* credit please ;)

What exactly should I give you credit for, and why?

The impracticality of light arrays has been reported and confirmed by a 
number of people who are long-time posters here. We can accept that they 
know what they're talking about. But in your case.. does anyone know who 
you are? I certainly don't remember seeing your name before this thread. 
If you want to challenge the notion that light arrays are impractical, 
you should provide such proof as is necessary to disprove everyone who 
has come before you.

> Now, by complex test, I don't mean a work of art, or anything pretending to
> be a "real" scene - by complex I mean very heavy duty in terms of what I was
> asking Povray to do. That includes both the scene and settings used for the
> render.

There's nothing particularly complex about the scene you described at 
all, *except* for the light array, which doesn't count!

-Xplo

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