[Opensim-users] Hoping for a fearless comparison of opensim vs unity 3D

[Dahlia Trimble]

Unity and OpenSimulator are not designed to cover the same application
space. Uinty is designed for mostly single player gaming and adds a few
features to help support multiplayer; whereas OpenSimulator is more
designed for multi-user shared collaborative experiences. You can build a
multi-user shared collaborative environment with Unity but it would require
extensive development as it's not really designed for that purpose.

Regarding physics, Unity has client-side physics. Whether this is "better"
really depends on the application. For a single user game, client side
physics can provide a more realistic experience as it's not affected by
network communication time and physical actions/reactions occure relatively
instantly. However, client-side physics brings about a new set of
challenges in a networked, collaborative environent. Consider the following
scenario: You have a space shooter game where asteroids are moving towards
earth. Players fly around in spaceships and fire weapons at the asteroids
trying to deflect them. Player A fires a weapon and the projectile strikes
the asteroid, deflecting it and scoring a point for player A. While this
happens, Player B also fires at the asteroid, destroying it. Due to
networking delays, player B's computer did not receive the event signaling
player A firing at and deflecting the asteroid until after player B had
destroyed it. Both players believe they deserve the score but only one
could have hit the asteroid. Had these events been processed by a central
server, both players would have observed the events in order and it would
be clear which player would deserve the score. Such situations are why
multi-user shared environments usually rely on central physics and event
processing. This is one area where Unity could use additional development.
There are, however advantages to having some client side physics even when
many interactions are controlled by a central server, such as some avatar
animation effects. I believe there's a lot that could be done to make the
SL/OpenSimulator experience appear more realistic by adding more
client-side physics in areas where it clearly helps.

I've had a fair bit of experience with interfacing Unity to OpenSimulator
in the past; I wrote a Unity based web viewer for OpenSimulator a few years
ago for a company named "Rezzable". Around that time I was also
experimenting with mixing client-side and server side physics and I learned
quite a bit about what can go wrong with trying to share client-side
physics over a network.

Regarding collaboration, Unity's editor is a single-user application.
Editing your environment and using it are completely different situations.
In OpenSimulator, they are combined into the same experience and others can
observe world building in real time and participate in the process.

To recap: Unity is really designed for games, and OpenSimulator is designed
for shared, collaborative experiences. If you want to develop single user
games or limited multi-user games, Unity is probably the best choice. For
shared experiences, OpenSimulator pretty much works out of the box.


On Fri, Jul 18, 2014 at 10:07 AM, Dr Ramesh Ramloll <r.ramloll at gmail.com>
wrote:

> Hello,
> I am starting this thread so that I can get some of your thoughts on this
> matter.
> Most of the time, from what I read, and from what prospective clients tell
> me, Unity 3D is so great! why don't you develop in unity 3D. Yes it runs on
> tablets is a big plus. This I do understand. It has better physics, yes
> clearly.
> What I am not sure about, and I hope you can share your thoughts,
> is whether it would be possible to create a collaboration centric, avatar
> centric application in  unity 3D. What I mean, is that whether you can have
> within a unity 3D world, avatars using objects to create new ones
> *collaboratively* , whether you can provide users with the ability to
> change their environments in natural ways, whether objects can be collected
> and shared, whether you have a shared white board, or collaborative
> document editing within a unity 3D world. And if yes, how long will it take
> to make these happen, may be it has already happened, do let me know with
> pointers to examples.
>
> And btw, why is it that I havent come across any voice chat demos of unity
> 3D applications that  run in a browser. I am thinking if Unity3D is really
> top notch, why have these things not appeared already as applications (may
> be they have, and I haven't seen them, please point to examples, if you
> know of them).
>
> And most importantly, what does opensim offers that unity 3D does not,
> that you think is important for users out there, from various domains, such
> as education, training etc...
>
> p.s. the thoughts about HighFidelity and all these new stuff coming up
> .... I still don't know, if all these wheels are going to be reinvented,
> the scene is really too messy to contemplate. It is becoming really hard
> for us developers to pick platforms. We don't have infinite resources, and
> we feel that we don't even get a chance to discuss application level
> stuffs, when the underlying platforms are already shifting so arbitrarily.
> Thanks
> Ramesh
> --
> 'Consider how the lilies grow. They do not labor or spin.'
> *Rameshsharma Ramloll* PhD, CEO CTO DeepSemaphore LLC, Affiliate *Research
> Associate Professor*, Idaho State University, Pocatello, ID 83209 Tel:
> 208-240-0040
> LinkedIn <http://www.linkedin.com/in/rameshramloll>, DeepSemaphore LLC
> <http://www.deepsemaphore.com>, RezMela <http://www.rezmela.com>, Google+
> profile <https://plus.google.com/103652369558830540272/about>
>
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>
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