Re: 2d circular union nav-mesh

Hey,

I'm pretty sure you cannot get away without clipping the test circle against
the container circles, tho I do not have proof.
You can probably use a slightly modified polygon clipping routine, storing
the edges as circle-arcs or NURBs and test for intersection with those.

Regards,
Marius



On Wed, May 26, 2010 at 1:11 PM, <[email protected]> wrote:

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> Hi guys,
>
> Does anyone have any references or pointers for how to constrain a small
> character (represented by a circle) within the interior of the union of a
> set of larger circles?
>
> The background is, the larger circles define regions of land where the
> small circle can navigate around (like a nav mesh), and the union of the
> these circles defines the entire nav-mesh. The character is not allowed to
> leave the interior of the nav-mesh and must remain wholly inside it at all
> times.
>
> Some diagrams:
>
> The general case, the filled circle represents the character and the
> hollow circles the land
>
> http://www.pfirth.co.uk/ex1.png
>
> My first attempt was to ensure the character was wholly inside at least
> one land circle, but that fails in this case:
>
> http://www.pfirth.co.uk/ex2.png
>
> In that example, if the character moves any further up, it will not be
> wholly contained in either circle and will fail, yet it should be able to
> navigate between them.
>
> Cheers, Paul.
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