POV-Ray : Newsgroups : povray.general : (not) a feature request Server Time
4 Aug 2024 20:12:50 EDT (-0400)
  (not) a feature request (Message 1 to 8 of 8)  
From: JRG
Subject: (not) a feature request
Date: 23 Jan 2003 16:35:06
Message: <web.3e305f35b952d19c978071460@news.povray.org>
I'm just wondering how difficult it'd be to add these simple keywords to the
light_source block:
-shadowless: I mean, I don't want the darn light to cast shadows. Period.
Maybe I still want it to show specular highlights why not? it's up to me
isn't it? I know that that behaviour is wanted, because users wanted fill
lights to behave this way and all but I'm pretty sure a lot of users here
would prefer to turn off specular highlights as they see fit.
-no_specular (or something like that) see above.
-no_diffuse: for those who think the combo pure radiosity lighting + fast
specular highlights (or photons) is just a dream.

Now, is there anyone who can tell me how to accomplish this? Which files
should I modify and how?

Thanks in advance.

P.S. I also think no_image objects should still affect radiosity. Again a
no_radiosity flag would leave the decision to the user. Endless
possibilities...

--
Jonathan.


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From: JRG
Subject: Re: a feature request
Date: 23 Jan 2003 16:55:08
Message: <web.3e30642f408126ce978071460@news.povray.org>
JRG wrote:
[cut]

The WEB interface has changed my subject! WTH?? It was "(NOT) a feature
request". grr

--
Jonathan.


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From: Thorsten Froehlich
Subject: Re: a feature request
Date: 23 Jan 2003 17:03:41
Message: <3e3066bd$1@news.povray.org>
In article <web.3e30642f408126ce978071460@news.povray.org> , "JRG" 
<jrg### [at] hotmailcom> wrote:

> The WEB interface has changed my subject! WTH?? It was "(NOT) a feature
> request". grr

No, the web interface is unable to do something like this.  It must have
been on your end.

    Thorsten


____________________________________________________
Thorsten Froehlich
e-mail: mac### [at] povrayorg

I am a member of the POV-Ray Team.
Visit POV-Ray on the web: http://mac.povray.org


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From: Christopher James Huff
Subject: Re: (not) a feature request
Date: 23 Jan 2003 18:07:04
Message: <cjameshuff-546699.18055223012003@netplex.aussie.org>
In article <web.3e305f35b952d19c978071460@news.povray.org>,
 "JRG" <jrg### [at] hotmailcom> wrote:

> -shadowless: I mean, I don't want the darn light to cast shadows. Period.
> Maybe I still want it to show specular highlights why not? it's up to me
> isn't it? I know that that behaviour is wanted, because users wanted fill
> lights to behave this way and all but I'm pretty sure a lot of users here
> would prefer to turn off specular highlights as they see fit.

Having shadowless and no_shadow? I don't think so.
I'd rather dump "shadowless" and have both objects and light sources use 
no_shadow. And no_shadow would only affect shadows, maybe include a 
fill_light() macro to make conversion simpler.


> -no_specular (or something like that) see above.

How about no_highlight? I don't think anyone would want a light with 
only one kind of highlight.


> -no_diffuse: for those who think the combo pure radiosity lighting + fast
> specular highlights (or photons) is just a dream.

That would indeed be useful, though no_diffuse is a little misleading if 
it emits photons.
Implementing these without impacting the rendering speed isn't easy, 
though, and still doesn't give the maximum flexibility. That would 
require something like light_groups, allowing you to specify how each 
light interacts with each object, probably at a cost of efficiency. 
Maybe include the basic options and a shading language capable of the 
more advanced combinations.


> Now, is there anyone who can tell me how to accomplish this? Which files
> should I modify and how?

Look through the code to see how the related features are implemented.


> P.S. I also think no_image objects should still affect radiosity. Again a
> no_radiosity flag would leave the decision to the user. Endless
> possibilities...

That's the problem...after a certain point, you may as well modify the 
source code, or use some language that can be evaluated on the fly.

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: chr### [at] tagpovrayorg
http://tag.povray.org/


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From: Slime
Subject: Re: (not) a feature request
Date: 23 Jan 2003 18:09:37
Message: <3e307631$1@news.povray.org>
> P.S. I also think no_image objects should still affect radiosity. Again a
> no_radiosity flag would leave the decision to the user. Endless
> possibilities...


The problem with all of these no_something flags is that they're not
backwards compatible. For instance, right now, objects have:

no_shadow
no_image
no_reflection

And some people want to add a no_radiosity flag to that, to sort of split up
the functionality of "no_image" into "no_image" and "no_radiosity". But
let's say that feature were added in version 4.0. That would mean that an
object with no_image would affect radiosity in version 4.0, but *not* affect
it in version 3.5. Now, this could be switched with the version directive,
but as more and more of these keywords were added, things could get
confusing, and it would be very difficult to update old scenes to work in
new versions.

I hope POV-Ray 4.0 addresses this with some sort of more advanced syntax.

 - Slime
[ http://www.slimeland.com/ ]


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From: Rich
Subject: Re: (not) a feature request
Date: 23 Jan 2003 22:26:15
Message: <Xns930CCFE4AC522spammindspringcom@204.213.191.226>
"Slime" <slm### [at] slimelandcom> wrote in news:3e307631$1@news.povray.org:
> The problem with all of these no_something flags is that they're not
> backwards compatible. For instance, right now, objects have:

Ack!!  Backwards compatibility should NEVER be a factor in determining 
features of new versions of *any* software.  The POV syntax is plain text, 
it's easy to edit a scene to fix/replace old code with new.  It might be 
time consuming (I'm currently converting an old 3.1 scene that used Halos 
extensively) but it isn't hard.  It's not even an issue of some people not 
wanting to upgrade to the latest version of POVRay because they can't 
afford the upgrade price.  <smile>  Backwards compatibility is the bane of 
all programmers!

I *really* want some kind of keyword that allows me to turn off radiosity 
calculations on an object-by-object basis, so I can use iso's in a 
radiosity scene without POV taking days between test renders.  <grin>

-- 
Rich Allen
(Remove SPAM from my address to reply by e-mail)


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From: Slime
Subject: Re: (not) a feature request
Date: 24 Jan 2003 08:17:33
Message: <3e313ced$1@news.povray.org>
> Ack!!  Backwards compatibility should NEVER be a factor in determining
> features of new versions of *any* software.  The POV syntax is plain text,
> it's easy to edit a scene to fix/replace old code with new.  It might be
> time consuming (I'm currently converting an old 3.1 scene that used Halos
> extensively) but it isn't hard.  It's not even an issue of some people not
> wanting to upgrade to the latest version of POVRay because they can't
> afford the upgrade price.  <smile>  Backwards compatibility is the bane of
> all programmers!

Regardless, it would be beneficial (mainly since the language is being
overhauled anyway), to re-implement these features in a backwards compatible
manner, so that people didn't *have* to convert old scenes. Because it's
plain that every now and then, we're going to want to add new no_something
keywords. It will also get tedious to have to say no_image no_reflection
no_radiosity (and then whatever other modifiers are added to the language
later on) when you want an object to only cast a shadow.

(Here's a question: should the shadow of an object with no_radiosity (but
without no_shadow) affect radiosity? Perhaps there should be a
no_radiosity_shadow keyword to clear this up? It gets messy.)

 - Slime
[ http://www.slimeland.com/ ]


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From: Warp
Subject: Re: (not) a feature request
Date: 24 Jan 2003 09:10:39
Message: <3e31495f@news.povray.org>
Slime <slm### [at] slimelandcom> wrote:
> (Here's a question: should the shadow of an object with no_radiosity (but
> without no_shadow) affect radiosity?

  The shadow is an illumination property of *another* object, not the object
casting the shadow. I don't see why it shouldn't affect radiosity. If that
another object is completely shadowed, what kind of light it could reflect
to its surroundings?

-- 
#macro M(A,N,D,L)plane{-z,-9pigment{mandel L*9translate N color_map{[0rgb x]
[1rgb 9]}scale<D,D*3D>*1e3}rotate y*A*8}#end M(-3<1.206434.28623>70,7)M(
-1<.7438.1795>1,20)M(1<.77595.13699>30,20)M(3<.75923.07145>80,99)// - Warp -


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