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Feb 5, 2000, 4:27pm

The AW Newsletter promises a lot of good new things will be happening
when AW 3.0 appears. Nothing specific is mentioned, but in the area of
Bots, there could be a number of additions to the Bot SDK. There will
always be unexpected uses of the old Bot SDK, but some of the expected
bots (mentioned in the SDK documentation itself) have never appeared.
These are the bots that wander about at random, moving in response to
the scene that they happen to be in. (Bots that follow a prepared path,
or obey explicit chat commands to come here or go there, have
owner-selected moves.) Randomly-wandering bot avatars should be as
realistic as other avatars, & should therefore avoid obstacles, like
trees and walls, or should fall from a tower but stop when they hit a
roof or an automobile.

The principal reason why these bots haven't been accomplished is that
the old AW 2.0 SDK didn't support collision detection. Every world has a
collection of data about its objects; one segment of this data is the
segment containing the object bounding boxes (the yellow lines appearing
around an object when you select it with a right-mouse-click are the
lines of the object's bounding box). There may be secrets hidden away in
the object data, but the object bounding boxes can hardly be considered
to be proprietary information. On AlphaWorld, you can print out the
object bounding boxes from an online file; but on most other worlds, you
can't get at them. (If you were very patient, you could create all the
world's objects one by one & count your keystrokes across all the sides
of all the objects; and then repeat this process for all the other
worlds.)

So the best single addition to the SDK would be access to the bounding
box data for the current world, either all at once (like Querying
property) or on demand (by submitting the model name of the object).
Then we could have realistic bots that wander about the way that citizen
and tourist avatars do now, without someone shouting at them "Bot! Go to
333S 444E 5.4A."

Feb 8, 2000, 5:02pm

I agree that bounding box information would be useful. I think it would enable a number of useful
stuff since right now all we have is a single spot for each object, no hint on size, real
orientation, height.. stuff like that.

However, say we had the bounding box information starting tomorrow, bots that successfully
circumvent obstacles on their way through the world would still be very hard to make. I would not
expect them very soon :)

Faber

Feb 8, 2000, 7:41pm

Bounding box info is nearly useless. It won't allow you to navigate hills
or stairs or ramps. It won't tell you how to enter a hollow object or even
walk under an arch. It'll tell you where things are that you have to walk
around but that's only a small part of the problem. Especially in a world
with a lot of hills.

Norm

[View Quote]

Feb 8, 2000, 11:04pm

Sure, it would be better to have access to the complete object data! But
partial data, like bounding-box data, is better than nothing at all. And bot
programmers can acquire some of the geometry routines that might eventually
apply to complete collision-detection, even to gravity.

In quite a few 3D engines, collision-detection is done in two stages: first, a
broad sweep of the object database, using bounding boxes; then, once the
nearest and likeliest barriers are detected, a narrow examination of the
candidate objects, using their face, edge, and vertex data as targets for
detailed geometric probes. Like Faber says, it's not easy to do, & doing just
the first part might make some programmers succeed at adding a new bot ability,
even if it is just stopping at walls or trees or breaking a fall on a mountain
peak or an automobile roof.

Renderware 3.0 has built-in full collision-detection, or so they claim. If this
means that the full ability will be passed on to bot programmers via the AW 3.0
SDK, then let it happen!


[View Quote] > Bounding box info is nearly useless. It won't allow you to navigate hills
> or stairs or ramps. It won't tell you how to enter a hollow object or even
> walk under an arch. It'll tell you where things are that you have to walk
> around but that's only a small part of the problem. Especially in a world
> with a lot of hills.
>
> Norm
>
[View Quote]

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