Gilles Tran wrote:
> People have been using my tree, grass, pipe etc.
> macros a lot in the last years. They have modified
> them and improved them. I'm glad of this and I think
> that it makes my work even more valuable, since it
> allows innovation and circulation of ideas. Allowing
> people to do this is also a way for me to thank all
> those who have done the same before. What is the
> global benefit in not allowing this ?

It's a personal benefit. I have not given my files to the public domain,
and I'd like to keep control of how and where they are distributed. That
is not possible if people can distribute modified versions of my files
as they please.

> Granted, a few people (including me) sell images or
> do commissioned work that include free material.
> In my case, the restritcion will prevent me from
> using your macros altogether, since I rarely know
> beforehand if I will make an image available for sale
> or not.

If you do make it available for sale, you can buy a license to use the
particle system commercially.

> Even if I don't sell it, it may happen one day that
> someone wants it for a book.

Would you gain any profit from this? If yes, see above. If not, this
might be a good situation to ask me for a special permission, since the
situation is a bit special (commercial work where you don't get any
profit yourself).

> I understand that people who provide free material
> can think that this is not fair that others benefit
> from it.

Exactly.

> Personally, I don't care whether my free stuff is
> used commercially or not : I do it to help and please
> people, and this includes people making a few bucks
> on the side.

I do not feel the same way.

> The possibility of people abusing this seems extremely
> remote in the case of POV-Ray.

Still, there are people who both can and will pay for a license to use
my files commercially, and I'd like to take that opportunity for *me* to
make a few bucks on the work I have done. And I think it's only fair.

> There are possible problems, but I don't think that
> a strict TOS will solve them, particularly when you
> wouldn't be able to enforce it.

As I've said, I can only appeal to people's honesty.

> if you think that your material has a market value,
> making it clearly commercial (instead of limiting its use)
> is the way to go.

Clearly commercial so that hobbyists will also have to pay to use it
non-commercially? That's not something I'm interested in. Or what do you
mean exactly?

> However, having been there myself, I'd say that
> it's your skills that you need to sell, not the
> product itself, whose uses are targeted at a largely
> penniless hobbyist crowd.

Penniless until the day they begin earning money on it. And until that
day, they won't have to pay me anything.

I'm not sure what you mean by "selling my skills rather than the product
itself".

> OK, what if Chris Colefax, or Jaime or I start doing
> the same... Or the POV-Team itself ? Anyone here want
> to see that ?

We surely couldn't blame them. (Of course, the POV-Team have more or
less promised that they will never do it, so it would be kind of strange
if they broke that promise.)

Gilles, your macros and object collection is of high quality, so I
wouldn't mind being required to credit you wherever I use it, and I
wouldn't mind having to pay for it if I used it commercially.

So no, I don't see the problem.

> In my experience, people are more than willing to give
> credit when credit is due.

Except the few individuals who simply are not aware that it's considered
polite to give credit in such cases.

> I think that NOT asking for credits is much nicer to
> users than asking.

This is just a small detail IMO. I'd rather make things clear.

> Also, *** requiring *** people to give you credit
> is too much to ask.

Why? I think it's quite common tendency for free things on the net,
isn't it?

> There are also priorities in what one can consider worth
> of credit or not and for me this decision only belongs
> to the artist.

No, in the case of my files it's not the decision of the artist. The
artist can buy a commercial license by paying me money, or buy a
non-commercial license by "paying" me credit where due.

> So again, by using your macros the user could risk
> violating the TOS some day.

I don't see how that can happen involuntarily. Users don't risk
violating the TOS if they follow it.

I appreciate this discussion, so please don't hesitate to pursue your
arguments further. It is not totally out of the question that I might
make changes to some of the terms... :)

Rune
--
3D images and anims, include files, tutorials and more:
rune|vision:  http://runevision.com (updated Oct 19)
POV-Ray Ring: http://webring.povray.co.uk

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Rune wrote:
> 
> I appreciate this discussion, so please don't hesitate to pursue your
> arguments further. It is not totally out of the question that I might
> make changes to some of the terms... :)
> 
> Rune
> --
> 3D images and anims, include files, tutorials and more:
> rune|vision:  http://runevision.com (updated Oct 19)
> POV-Ray Ring: http://webring.povray.co.uk

I can understand your point, there is no real reason for me to
disagree and still I felt a bit uncomfortable when I read about
this.

Let me ramble a bit, perhaps it makes sense...

I have been using POVRay for commercial purposes (still do, come
to think of it) so I might be involved somehow, if I used your
particle system. I haven't had the need for it yet and I don't
really think I will. 
If I _would_ need it it would probably be for some detail
somewhere, not really be the key part. In such a case I think
I'd try to figure something out to simulate what it should look
like. I might also consider looking for some ready-to-use
alternatives. Running into a TOS like yours I'd probably stop
reading halfway and turn back to my own feeble attempts or look
somewhere else.

On the other hand, if it were free, with a line somewhere saying
that you'd appreciate any credit (financial or otherwise) that's
relevant, I would probably already have tried the system and
incorporated it in my work. If, at such a point, I'd realize the
value of your contribution I wouldn't hesitate paying for it. I
would probably even be willing to pay far more then (relieved
that I got the job done).
I have indeed done that for a package which a use a lot.

What Gilles already indicated is that you might benefit far more
by "selling your skills". With your particle system you have the
opportunity to show what you can do (as with lots of other
stuff). With such talents it's probably easier to earn a few
bucks then by selling a package in a freeware oriented
community. 

To get to the point: the main problem I see with your TOS is
that you depend on the honesty and good will of users, since you
have no way of protecting your package. It is exactly these
people who would probably share in their profits anyway (if any)
while the ones your setting the TOS up for wouldn't.
And I don't mind giving credit where credit's due but there
isn't always an appropriate place.

Still, as I said at the beginning, I can understand your point
of view.

CheerS!

Remco

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> I appreciate this discussion, so please don't hesitate to pursue your
> arguments further. It is not totally out of the question that I might
> make changes to some of the terms... :)


Heh, I'll give this a shot then. =)

Mainly, the only argument I have is a moral one. You have every right to ask
for compensation for commercial use. However, the whole thing about POV-Ray
itself is that it's free. If it weren't free, we wouldn't have the community
here that we do. We have people who use it for all different reasons, from
those just playing around to those using it professionally. It's the
*essence* of our community that there are no strings attached. We're all
just having fun with a program we like to use, and contributing to it in
some cases for no reason other than the benefit of the community. Heck,
there's even povlegal.doc that prohibits the use of the program
commercially.

Now, while this legal restriction doesn't apply to scene files themselves,
the *spirit* of POV-Ray and the POV-Ray community does. By asking for
something in return for your contribution, you're partially destroying that
spirit. Just like the rest of us, you learned a lot from this community and
from your use of POV-Ray over the years, and, most likely, you wouldn't have
been able to write those include files if it weren't for the fact that the
creators of the program let anyone use it for free, for any purpose. The
compensation we *all* get for contributing to the program is the
contributions of others. That, plus the fact that when someone else uses
your work, it makes you feel good. That's why I'm working on my little patch
right now; not in the hope of making a few bucks, but in the hope that
someone else will use it and think it's cool.

So, I think that's the best argument I can propose. I don't feel comfortable
using your particle system since it puts a restriction on me that if,
sometime in the future, I'm making an image for some commercial software,
and I reuse some of my old POV-Ray code that makes use of your particle
system, I'll have to resolve that issue.

It really is excellent. Just keep it free. =)

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

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Slime wrote:
> 
> > I appreciate this discussion, so please don't hesitate to pursue your
> > arguments further. It is not totally out of the question that I might
> > make changes to some of the terms... :)
> 
> Heh, I'll give this a shot then. =)
> 
> Mainly, the only argument I have is a moral one. You have every right to ask
> for compensation for commercial use. However, the whole thing about POV-Ray
> itself is that it's free. If it weren't free, we wouldn't have the community
> here that we do. We have people who use it for all different reasons, from
> those just playing around to those using it professionally. It's the
> *essence* of our community that there are no strings attached. We're all
> just having fun with a program we like to use, and contributing to it in
> some cases for no reason other than the benefit of the community. Heck,
> there's even povlegal.doc that prohibits the use of the program
> commercially.
> 
> Now, while this legal restriction doesn't apply to scene files themselves,
> the *spirit* of POV-Ray and the POV-Ray community does. By asking for
> something in return for your contribution, you're partially destroying that
> spirit. Just like the rest of us, you learned a lot from this community and
> from your use of POV-Ray over the years, and, most likely, you wouldn't have
> been able to write those include files if it weren't for the fact that the
> creators of the program let anyone use it for free, for any purpose. The
> compensation we *all* get for contributing to the program is the
> contributions of others. That, plus the fact that when someone else uses
> your work, it makes you feel good. That's why I'm working on my little patch
> right now; not in the hope of making a few bucks, but in the hope that
> someone else will use it and think it's cool.
> 
> So, I think that's the best argument I can propose. I don't feel comfortable
> using your particle system since it puts a restriction on me that if,
> sometime in the future, I'm making an image for some commercial software,
> and I reuse some of my old POV-Ray code that makes use of your particle
> system, I'll have to resolve that issue.
> 
> It really is excellent. Just keep it free. =)

You summed up my thoughts very well, plus I agree with Gilles and Remco.
It is almost like a slap in the face of the entire POV-Ray community and
came quite unexpectedly. It sets a new precedence and a possible turning
point in the way the include files are distributed and used. Kinda sad,
really.

Maybe I should place restrictions on the use of my links collection. If I were
to charge a nominal fee for every link accessed it would really help supplement
my meager income. Do you think anyone would mind?

-- 
Ken Tyler

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I can't read Ken's mind so I could be wrong to say this. Maybe it's that
"derivative works" part that's unclear.

I remember when I first started with POV-Ray and the same wording was used
about the demo scenes, I think. Seemed obvious that you simply don't add
parts of other people's works into your own renderings and call them solely
your own (if stating anything at all for that matter). The gray area to me
would be whether a concept or idea or actual object is modified and used
without credit. Well, a modified object is certainly a derivative, right?
Anyway... again my point, like before, is about how this can get confusing
without precise and clear wording. I think you tried that, Rune, and I
understood it enough.

If the questionability comes down to usage of the includes and thereby a
person must relinquish sole ownership of whatever they make with them then I
can see the problem for casual, non-profit use. Of course all this hinges
upon "publishing" or uploads to the web, not at home use for example.

I grabbed a quote from the Terms Of Use which is the only part I think I
might muddle up:

"My files are for your enjoyment and education but may not be the basis of
any derivative works. Also, you may not alter, correct, or improve any of my
files in any way."

I always end up changing files in one way or another, it's second nature. I
try not to put them back out there without acknowledging that fact. Major
includes like yours are easier to refrain from sharing and spreading with
"modifications" though, simply because of their inherent complexity and so
changes are more studiously undertaken. For example, I doubt I ever e-mailed
anyone a changed a famous Colefax include. Simpler files are easier to
pollute without consciously reworking them, and they usually aren't
constrained to any kind of copyrighting in the first place.

Well, if I made any sense there, that's some of my input about the subject.
Basically, POV-Ray files are so morphable since anyone can edit the scripts,
unlike programming code. Perhaps this is the most difficult thing to refrain
from and the terms of use specifically warn against that. Should be plain to
everyone that they can't redistribute them, so that's not unclear to me at
all.

Or maybe Ken just likes picking on you Rune? ;-)
--
Farewell,
Bob

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"Ken" <tyl### [at] pacbellnet> wrote in message
news:3DB35B04.FFB0E06C@pacbell.net...
>
> Maybe I should place restrictions on the use of my links collection. If I
were
> to charge a nominal fee for every link accessed it would really help
supplement
> my meager income. Do you think anyone would mind?

I might owe a lot.

Post a reply to this message

"hughes, b." wrote:
> 
> "Ken" <tyl### [at] pacbellnet> wrote in message
> news:3DB35B04.FFB0E06C@pacbell.net...
> >
> > Maybe I should place restrictions on the use of my links collection. If I
> were
> > to charge a nominal fee for every link accessed it would really help
> supplement
> > my meager income. Do you think anyone would mind?
> 
> I might owe a lot.

According to the server stats for http://www.povray.org/resources/links/
it has received close to 10,000 hits already this month alone and there
are still 11 more days to go. The hits on the subpages is even greater
than that. If that's any indication of the popularity of that resource
the implications are staggering :)

-- 
Ken Tyler

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"hughes, b." wrote:

> Or maybe Ken just likes picking on you Rune? ;-)

I wasn't picking on Rune. I was merely attempting to stimulate his
thought processes.

-- 
Ken Tyler

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In article <3db2c91c$1@news.povray.org>, run### [at] mobilixnetdk 
says...
> I don't feel that way. But then, I have very little money myself, which
> probably makes even worse the thought of other people making profit on
> my work.

I can't say I am particularly comfortable in either side of the fence. I 
find that increasingly you have to either wait around in hopes someone 
will put out an open source program that by some miracle contains the 
code you where looking for 3 months earlier, have to intentionally break 
the licenses of 6-7 people, each of who have a piece of something you 
need to get the job done, but all of who seem to think using the code for 
anything that make money is bad, or buy some software program that has 
all the features integrated and is totally useless because you can't use 
most of them the way you intended. It bugs the hell out of me... So in a 
general sense I do understand your view, but at the same time being not 
spectacularly skilled at 3D art, having so little money have trouble 
keeping my bank accounts open and being in no position to buy anything 
unless I absolutely 100% have to have it and can't find a something else 
to use instead, I also find your attitude seriously irritating. lol

I will probably take a look, but being another of those 'have very little 
money' people I doubt I will be using it even for my own personal use 
(which for things like this is imho a silly concept right from the 
beginning...).

Post a reply to this message

On Sun, 20 Oct 2002 17:18:29 +0200, "Rune"
<run### [at] mobilixnetdk> wrote:

>This can in no way be compared to the complexity it is to define any
>given surface in the term of a function. With the object approach you
>can have a CSG object with hundreds of primitives in it and make the
>particles collide with it, or you can use a mesh object for that matter.

Meshes are quite easy to define in terms of functions. Besides, what
Christoph is describing are force fields while what you are describing
are penalty functions. They are different and have different uses.

>That is next to impossible with functions. I don't see why you seem to
>think that it is such a great advantage to use function based
>environments, if you compare the pros and cons.

As I said, they are different approaches to the same problem.
Collision is a complex problem because it involves instant change in
momentum (which is never instant in reality), energy loss, extreme
stress gradients and whatever you can think of. Even for a pure
particle system, where you don't deal with volumes or deformable
bodies, collision is quite a challenge.

Using penalty functions (as you do) has the advantage that it is
generally simpler to implement and faster to compute. The problem is
that due to the infinite gradient of the penalty function (the
function being 0 outside the object and non-zero inside), it is
impossible to use higher-order integration methods.

With force fields (usually based on proximity functions), you always
get prolonged collisions. This can be problematic with steep collision
angles because the particle may actually gain energy from the field,
which is quite impossible, so care should be taken. On the bright
side, you can predict quite well the behavior of particles in such an
environment due to the well-defined energy gradients, so you can use
implicit integration methods for higher step sizes (see Baraff, David
and Witkin, Andrew."Large Steps in Cloth Simulation."
http://www-2.cs.cmu.edu/~baraff/papers/sig98.pdf)

One could combine the best of both worlds, as Xavier Provot is doing
in his cloth simulations.

One could also use adaptive time steps. I haven't read anything on the
subject and so can't give you any links, but it seems like a pretty
obvious thing to do so I guess someone must have implemented it
already :)

Looking forward to further development.


Peter Popov ICQ : 15002700
Personal e-mail : pet### [at] vipbg
TAG      e-mail : pet### [at] tagpovrayorg

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