[Fiware-miwi] Tundra scene synchronization protocol

["Lasse Öörni"]

> But why is position not a physical parameter but velocity is? This is
> essentially the same thing (the second is simply change of the first
> over time). This is why in my thinking they belong together.
>
> Density, friction, mass, and other stuff is very different and this is
> what I would consider under a physics component.
>
> Yes, you need the velocity for a lot of the physics computation but this
> is also true for the position and orientation.

Hi,
it's true that if a Placeable's transform is changed over time by a script
with a high frequency (every frame for example) it would produce the same
appearance of velocity as if it was driven by a physics simulation.

However, we can not know in the network protocol if the position will
continue to be updated with a steady frequency, therefore without a
RigidBody we interpret the transform changes as discrete ("teleporting"
the object around so to speak) and will not perform smoothing or dead
reckoning.

Naturally there's room for improvement regarding this, this is just the
current state of implementation. I would for example imagine some objects
having velocity without an actual heavy-weight physics simulation. Then,
there naturally will also be unmoving objects which only need a position
and not a velocity attribute.

-- 
Lasse Öörni
Game Programmer
LudoCraft Ltd.