[MUD-Dev] Room-based vs. coordinate-based

clawrenc at cup.hp.com clawrenc at cup.hp.com
Thu Jun 5 14:41:13 CEST 1997


In <3.0.32.19970604221304.00a03024 at mail.tenetwork.com>, on 06/05/97 
   at 08:07 AM, Jeff Kesselman <jeffk at tenetwork.com> said:

>At 08:20 PM 6/4/97 PST8PDT, Chris Lawrence wrote:

>>The approach which I'm currently moving towards is somewhat related to
>>this:
>>
>>The entire world lies within a single coordinate system  (32bit cube).
>>
>>Domains within that global coordinate system are marked off as being
>>"units".  A domain is defined as a 3D space as deliniated by a matrix
>>of coordinates. Typically this means a cuboid space (eg a rectangular
>>building). 

>This sounds alot like an Octree . Are you familair with the data
>structure?

Yup, an oct tree is just a 3D version of a quadtree.  Nope, this isn't
an oct tree, and really bears no relationship to an oct tree.  

Reasons:

  The arrangement of domains has no logical order within the
coordinate system.  The only reuirement is that the lumps in a domain
cannot overlap.

  Different domains however can overlap (ie occupy the same coordinate
space), something which is not allowed within an oct tree.

  A domain can consist of several lumps, and while lumps are usually
cuboid, quite often they are L-shaped, V-shaped, W-shaped, or other
more complex forms.  By definition the sub-divisions in an oct tree
are cuboid.

This is a much more general form.  There is really no implicit order
or reasoning to the subdivision of a coordinate space into domains. 
In fact, within fairly loose limits, I consider sub-domains to exist
in parallel with the domains they are defined in.  Thus:

 +--------------------------------------------+
 |                                            |
 |                                            |
 |           33333333                         |
 |      A    3333C333C    B                   |
 |           33333333                         |
 |   1111111444433333            2222222222   |
 |   1111111444433333            2222222222   |
 | O 111P1114Q44R3S33T   U       2222V22222WX |
 |   1111111444433333            2222222222   |
 |   11111111111                 2222222222   |
 |   11111111111                 2222222222   |
 |                                            |
 +--------------------------------------------+

Where the outer box is the global domain, '1' is domain #1, '2' is
domain #2, '3' is domain #3, and '4' is where domains '1' and '3'
overlap.

The player at A could walk to B without ever passing C.  Similarly for
B in reverse.  However B could walk in the same direction as A, and
would suddenly meet and join A on his way to B at C.

Given: O is in the global domain, P in in #1, Q is in #1, R is in #3,
T is in the global domain, and U is in #2.

O can see only T U W and X clearly.  

If O walks east to X he will pass T U and W.  If P starts walking west
at the right moment he'll pass Q and join O at R.  S would join O at
T.  P would not see S until they met at T.  etc.

--
J C Lawrence                           Internet: claw at null.net
(Contractor)                           Internet: coder at ibm.net
---------------(*)               Internet: clawrenc at cup.hp.com
...Honorary Member Clan McFUD -- Teamer's Avenging Monolith...




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