[vos-d] parameterized views

[Reed Hedges]

I thought about this a little a while ago.

1. My thought for server side control of a "View" was to use something 
sort of similar to access control, where you write a set of rules that a 
vobject can use when it recieves a list-children request. A given rule 
also needs to be re-evaluated as the world changes in some way, and 
generate a child-inserted notification.  What kinds of changes matter 
would vary by each rule, so a rule would also be a listener to the world 
and the avatar or whatever else. libvos could provide a specialization 
of the Listener API for this particular purpose, integrated with the 
View rules API.

That way has the advantage of basically being hidden from the remote site.

2. Another possability is to simply have a "View" vobject for each 
client that the server adds/removes objects to and from.  The client has 
to use that View instead of e.g. the sector in a 3D world.

This way has the advantage of basically requiring no changes to VOS, and 
is very simple, but with the disadvantage of extra Vobject overhead and 
it requires that all clients be aware of the "View" convention.

I think you had this same idea Pete, at least for A3DL (we talked about 
it in Boston this summer)?


3. For client side AOI in a 3D world, my thought is that 3D objects have 
bounding box or radius properties, and since properties are now 
basically part of the VOS core, support some simple math expressions 
compared to property values in search queries.  Or a client does two 
searches, once to get a list of all objects, their positions and bounds 
info (which is not a ton of data) then a second search to only get those 
that fall in its AOI.   Maybe a sector should suggest.

Reed