Re: [Pyode-user] using ODE/PyODE for finding nearest point of intersection

[Matthias B. <ba...@ir...>]

Maciej Kalisiak wrote:
> range to the closest obstacle.  I've experimented with the collision
> detection routines in pyODE, and it looks like I might get it to work,
> but the issue is that I get back collision contact points, which
> usually don't necessarily correspond to the *closest* point, and for
> certain shallow collisions, when there is only a single contact
> generated, I get slightly weird/erroneous position of that single
> contact.  I guess I'm wondering if there is a way to modify/choose an
> alternate contact point generating method.  Any ideas?

I'm not aware of any ODE options that let you control how the collision 
detection determines contact points, so I doubt that the above approach 
will really give any reliable results.
You could use the above approach if you would find another collision 
detection library that can also compute distances. I believe SWIFT is 
such a library (http://www.cs.unc.edu/~geom/SWIFT++/).

Another option might be testing the distance to an obstacle in a 
particular direction via a ray geom. This has the disadvantage that it 
only tests one discrete direction which means you have to use a bunch of 
rays for approximating your range scanner, but at least it yields the 
exact distance.

- Matthias -