[Adonthell-devel] Re: Next steps ... collision detection

[Kai Sterker]

On 8/22/07, Kai Sterker <address@hidden> wrote:

> Now, the only drawback is that character collision is calculated
> against triangles, meaning that our objects would have to be composed
> of those. I really don't want to go so far that a true 3D program
> becomes required to create object models. At most, there should be a
> set of basic shapes that could be scaled and transformed to fit the
> underlying 2D graphic most closely.

See the attached file for some examples. Basically, all I used as
bounding boxes are cubes that have been deformed (some of them in a
way that two corners share the same point, resulting in triangular
shapes). I don't know how well something like that would work out, but
I believe it could be pretty sufficient.

> (OTOH, using an existing 3D modeler to create those basic shapes might
> save us some work, so we should also consider it).

I had some more thoughts about that, but I lean more towards
implementing something custom; at least if we'd stick to those simple
boxes from the example. The idea would be that it lets you compose the
2D object from any number of images (something that was possible with
the v0.3 object format), then add boxes and change their corners to
best fit the 2D object.


Barring objections or better ideas, I'll go ahead and implement the
algorithm from that PDF [1] for the current demo map. The objects on
there should be simple enough to create proper bounding boxes without
any tool. If stuff works out well enough, I'd start work on an object
editor.

The goal would be to get at least the collision stuff done before the
end of the year. Not sure how complex the editor will get. I would
like to implement the path-based tagging for browsing graphics in our
gfx tree [2], in a way that it can be reused for browsing objects in a
future map editor. The rest is hopefully not that much different from
what dlgedit does: moving objects on a canvas and fairly simple
geometry.

Still, if I am to do it alone, it will take a while. So any help on
that is more than welcome.

Kai

[1] http://www.peroxide.dk/papers/collision/collision.pdf
[2] http://lists.nongnu.org/archive/html/adonthell-devel/2007-07/msg00004.html
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collision-demo.jpg
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