Christoph Hormann wrote:
> Nice. And congratulations for finally finishing it. :-)

Thank you. :)

> - from what you write in the documentation about
> the collisions i conclude you have not solved the
> 'particles penetrating the surface'- problem.
> You might try function based environments like
> i'm using for my mechanics simulations.

It's not a big problem. Under most circumstances, none or very few
particles fall through the surface. Wouldn't function-based environments
require the user to specify the environments as functions? As simplicity
is one of the major goals in my system, I want the environment to simply
be an object, as that is much easier to control, and more intuitive too.

> - i have not checked the code but from what you
> write in 'Inner workings' gravity is added to
> the position ("Each particle is moved by it's
> current velocity (current location minus last
> location) plus gravity (for example -y)") while
> it should be added to the velocity in fact.

That would be true if I had one variable for location and one for
velocity, and then could calculate the new location based on this. But
in fact I have one variable for the old location and one for the new
location, and then I can derive the velocity from this. So when I add
gravity to the new location but not the old, then it's the same as
adding gravity to the velocity.

> I understand if you don't want others to modify
> your tool and redistribute changed versions but
> requiring everyone to contact you before publishing
> a picture/animation using your file seems a bit
> exaggerated.

Yes, it's a bit over the edge, I know. :/  I might change it. It's
mostly there because I really like to get contacted when people have
used my utilities for something...

> Forbidding to use your include file for producing
> commercial work is to some extent understandable
> - you don't want others to make profit with something
> you put a lot of work into and none the less give
> away for free

Exactly.

> but on the other hand such a restriction will almost
> surely prevent a great success of your tool since a
> lot of people will refrain from using it from the
> beginning with such a restriction.

Well, it's important for me that people don't make profit on my work;
perhaps more important than how great success my tool gets. Besides, if
people want to make profit on it, they can either make an arrangement
where they buy a license from me, or if they are going to make very
minor profits only, they can obtain a permission from me to use it for
free anyway.

Maybe I should make this part in bold:
"If you would like to do something with it that is not allowed according
to the terms described here, you can always ask me for a special
permission."

Or maybe I should rewrite the terms of use completely. Dunno. I'm glad
to discuss them and to get input and thoughts on them.

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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