Locales, Boundaries and Portals

I finally got round to watching the amazing Half-Life 2 Portal Video and it reminded me of the locales and boundaries that I implemented in MASSIVE-3 (which were themselves based on the Locales in MERL’s SPLINE).

MASSIVE-3 represented the virtual world as a partially replicated scene graph. Locales were frames of reference in the scene graph and boundaries were links between locales. Transforms on boundaries defined the locales relative positions, scales, rotations and rendering effects, allowing CC-TV boundaries to tiny versions of distant locales, boundaries to shadow versions of locales, torroidal universes of locales joined by boundaries which linked back on themselves and many of the effects which Richard Bartle suggests are impossible in a graphical virtual world.

We then added the concept of temporal transforms across boundaries which contolled the replay of events recorded in the target locale allowing links to locales in the past or to slow motion versions of current locales (we didn’t manage links to the future, unfortunately).

Locales and Boundaries in MASSIVE-3 were lots of fun to play with and the Half Life video shows that they’re even more fun with gravity and guns.

About babbagelinden

Software Engineer at Linden Lab
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4 Responses to Locales, Boundaries and Portals

  1. Salazar Jack says:

    My mind just esploded.

  2. Textual worlds are nodal in their very being. Every location is a point, linked arbitrarily to other points.

    Graphical worlds are continuous in their very being. You can connect them together by making self-contained spaces and treating those as nodes, so you could enter Narnia through a wardrobe, but those self-contained spaces are not themselves nodal, they’re continuous.

    The TerraNova discussion you cite was (at least at the beginning, before it veered off into the realms of controlling the subconscious) about the difference between text and graphics for creating virtual worlds. The examples I gave of things you can’t do in graphical worlds were varied, but some did concern the inability of such worlds to do things like have rooms which contain themselves, which I guess is what you’re referring to here.

    The thing is, although you can implement these features in a graphical world, you basically have to do so by implementing them as nodes. You don’t have a single, consistent, continuous virtual world: you have several mini-worlds that are connected via a network of nodes. We usually see this in today’s game worlds as zones and instances, but you can be more physics-breaking about it if you want to be.

    However, what you’re doing when you take this approach is chopping your continuous world up into discrete chunks. Each chunk is itself still subject to the constraints inherent in its being a continuous world. If you want to break the continuousness again, you have to introduce new nodes, and then if you want to do it again you have to partition it again, and if you keep on wanting to do it eventually you reach an “atomic” state in which the continuousness has broken down – a world of points (nodes) rather than of surfaces and spaces. When you’ve done that, you can truly create everything a textual wolrd can create, but you’ve lost all the power you had with the graphics.

    So no, I’m not saying that graphical worlds find these effects “impossible”. I’m saying that if you use them, you’re taking the path to the textual model. In the Terra Nova post, Cory asserted that textual and graphical worlds were fundamentally different; the continuousness of the graphical world is a cornerstone of this “difference”. By showing that there are some things you can only do things in graphical worlds by adopting the textual nodal model, that demonstrates that fundamentally the worlds are the same, which is my own point of view.

    These things aren’t impossible in a graphical world; they’re only impossible in a graphical world that is “fundamentally different” from a textual world.

    Richard

  3. Jim Purbrick says:

    Hi Richard, thanks for dropping by! Yes, the effects I’m talking about here are based on linking frames of reference and so are a more nodal approach to structuring graphical worlds, but the spaces being linked are still spaces and they can be overlayed and can co-exist rather than self contained. The door to the wardrobe can be left open and you can see Narnia on the other side. A self referential link can place the room you’re in on the table in the room your in, complete with a smaller version of yourself looking at a table with yet another smaller version of the room and so on. Graphical worlds don’t need to be a single continuous space and textural worlds don’t need to be nodal, go north could easily move you 1 meter north in a text world rather than to the node to the north. Text worlds can describe impossibly twisted spaces and graphical worlds can show them. The half life portals video reminded me of what fun it is to play around with graphical worlds to build impossible spaces in the same way that it’s fun to play around with multiple mirrors to create illusionary infinite tunnels.

  4. >Graphical worlds don’t need to be a single continuous space and textural worlds don’t need to be nodal

    I agree: both can implement the other’s basic form. That makes them fundamentally the same, rather than fundamentally different. This is what I was arguing in the Terra Nova post.

    >Text worlds can describe impossibly twisted spaces and graphical worlds can show them.

    Well, they can show a 2D image of them (2D because that’s what screens display). They’d have a hard time showing a hypercube – not that players of textual worlds would necessarily find it easy either, of course!

    >The half life portals video reminded me of what fun it is to play around with graphical worlds to build impossible spaces in the same way that it’s fun to play around with multiple mirrors to create illusionary infinite tunnels.

    It can be even more fun. You can make the links conditional on the viewer, so that when I look through the wardrobe I see Narnia but when you look you see Middle Earth.

    Richard

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