A while ago, in
, I considered it a good idea to remove the "groups" feature from
the Map Editor. This was fueled by the observation that entities too can
naturally and inherently serve for grouping the individual elements in a map.
Keeping a second, explicit mechanism for the same purpose (the "groups"
feature) only seemed to be a redundant burden. Therefore, the intention was to
turn the existing two
methods for grouping into a single method, to be
implemented by having entities subsume the functionality of the former groups,
thus making groups fully redundant so that they could be removed without
Alas, after the change was complete and a considerable effort had been spent to
make entities and entity hierarchies work as well as groups did, the first
tests and feedback quickly showed that it didn't work out, and that my
assessment of the situation (and my enthusiasm for entities, or in fact, the
entity component system) did this time not lead to the desired solution.
Practically speaking, we found that the "groups", as they were implemented
before, were just too good and too convenient to be removed: my attempt to
achieve the same with entities was just not on par (think e.g. of the "Hide
Other" button). Considering this more closely, it turned out that this was not
a problem of the implementation, but of a more principal nature:
and their hierarchies are an excellent way to organize
(group) map elements in terms of the game or the virtual world that is being
developed: You use entities to model game objects like players, opponents,
cars, lifts, or anything else that is relevant for the game.
, however, serve a quite different organizational purpose that,
in hindsight, is orthogonal to that of entities: With groups, you express
features that are important to the map designer's workflow or are of technical
relevance – but not to the logical modeling
of a virtual game
Therefore, I'm currently working on undoing the commits that removed
"groups" from the Map Editor, and on reintroducing them soon. At the same time,
I will take the opportunity to rename the former "groups" to "layers", because
"groups" is a too general word (entities group map elements, too!), whereas
"layers", with their analogy to 2D drawing programs, seem to describe the
purpose of the feature in a more precise and more intuitive manner.
Entities group map elements by their logical meaning in the
virtual game world, as observed by players, as needed by script
authors, as seen by the core engine, etc.
Layers group map elements to facilitate technical details for
the map designer, e.g. to temporarily hide objects, to lock them from
being accidentally modified, etc.
Note that this is currently still a work in progress: I'll post here again as
soon as the
completely implemented and committed.