
Nvidia Extends PhysX for High Fidelity Simulations, Goes Open Source - foogered
https://blogs.nvidia.com/blog/2018/12/03/physx-high-fidelity-open-source/
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CositaS
Can anyone who has used both give an impression of how PhysX compares to
Bullet?

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aerophilic
Has anyone used this platform extensively? How does it compare to other
options? In particular Gazebo for ROS?

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Elte
It is my understanding that PhysX is more comparable to a physics engine, like
Bullet Physics or Open Dynamics Engine, both of which Gazebo integrates.
Perhaps they could now integrate PhysX as well...

EDIT: When I say "integrates", I actually mean "interfaces with"; you can run
Gazebo simulations using either physics engine (although switching between the
two is not quite as simple as that).

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craftyguy
It's a BSD license.

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CompelTechnic
>It will be available as open source starting Monday, Dec. 3, under the simple
BSD-3 license.

Doesn't the repo saying it is copyrighted contradict the BSD-3 license?

[https://developer.nvidia.com/physx-sdk-
home](https://developer.nvidia.com/physx-sdk-home)

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cstrahan
(Note that I am not a lawyer...)

In a nutshell, copyright ownership gives the owner(s) the choice to license
their work as they see fit. The word "copyright" is often misunderstood as
meaning "copying of the work in question is prohibited by law" \-- people
often throw around the phrase "oh, you can't copy that - it's copyrighted!"
\-- but that's not what copyright means.

Because the misunderstanding generally comes from people's experience with
books, I'll use that as an example.

Say I write a book. As the author, I'm now the copyright owner of that book. I
could then sell (or give away) that book under whatever terms I choose. In the
real world, those terms usually are something like "you may _not_ make and/or
distribute copies", and the rationale should be obvious: if an author's income
depends on people buying their books, they're going to have a hard time paying
bills if people make (or distribute) copies.

But back to me and my book. My income is independent of any copies sold, and
if someone can't afford the book (or is even on the fence), I'd prefer they
have access to the information contained therein rather than require they pay
me. In my case, what I might do is ask that people pay me if they're willing
and able, but allow for people to copy and redistribute the book if necessary.
I might also allow people to make derivative works. That would be done by
providing a license; that could be, say, one of the BSD licenses, or GPL, or
one of the Creative Commons, or whatever.

Now, what prevents someone from saying "Hey, cstrahan has written a cool book;
I think I'll just copy it and release it under incompatible terms in which
everyone is required to pay me and redistribution is prohibited!"

That's where copyright comes in. I'm the owner of the work, and so I'm the
only individual legally entitled to distribute that work under my choice of
license. If someone tries to distribute my work under an alternate license,
they're in violation of copyright law.

In short, copyright ownership and the terms of (re)distribution are two
separate concepts that shouldn't be conflated.

