Broad phase pair filters cannot access body information about nphysics HOT 2 OPEN

I investigated having nphysics define its own BroadPhasePairFilter trait but almost 100% of the collision logic happens in ncollide (unsurprisingly). So it looks like this will have to be a change within ncollide.

I suspect the best approach would be to modify the BroadPhasePairFilter to the following:

pub trait BroadPhasePairFilter<N: RealField, Object, Handle, Set>: Any  + Send + Sync {
    fn is_pair_valid(&self, b1: &Object, b2: &Object, h1: Handle, h2: Handle, set: &Set) -> bool;
}

where Set becomes the BodySet in nphysics. This will require a change at every step between nphysics and ncollide's src/pipeline/glue/update.rs, so it's a fairly sizable change. I'll wait to start working on this until I get input.

from nphysics.

Alternatives discussed on Discord:

• Using an associated type with a default and implementing a default fn is_pair_valid_in_set.
• Creating a new trait BroadPhasePairSetFilter that is auto-implemented for (or auto-implements) BroadPhasePairFilter

from nphysics.