Re: [Sserver-three-d] Fw: [sserver-commits] CVS:rcsoccersim/rcssserver3D/lib/oxygen/physicsserverspace.cpp, 1.16, 1.17 space.h, 1.

[Markus R. <rol...@un...>]

Hi,

Feng Xue wrote:
>     Yes, the nao model has been modeled like that(some bodyparts are in 
> some bodyparts totally). And if I use universal joint instead, it 
> is probably okay. But the universal joint is not equal to two hinge 
> joints and is hard to control for the joint limits according to current 
> work. Besides, refering to Webots' implemention, they use hinge joint on 
> all the joints too.

I still don't see why it is necessary that two geoms are constantly
colliding by design in the nao robot model. But if that's a requirement,
so be it.

>     The test is expensive because of the GetSpace() call. Maybe we can 
> solve it by a simple cached variable of parent space :-D

The first thing you come up with is not always the best solution. Please
stop modifying core parts of the physics implementation without some
discussion _before_ committing_ something!

Please describe your change on the mailing list first or use an
experimental branch [1] in the CVS.

In your current work style it is quite hard to follow your changes and
work on a solution.


Concerning your latest change to the Collider class: I think carrying a
'space' pointer in each Collider may work but is a quite heavy weight
solution. You further don't adapt the pointer if the geom is moved to
another space.

I think it would be nice to query special properties of Spaces without
following three pointers (from dGEomId to Collider to Space)...

The ODE library already provides a function to get the spaceId given a
geomId (dGeomGetSpace(dGeomId)). So given dGeomId obj1 and obj2 in Space
::HandleCollide it is easy to get and compare both spaceid.

>From this point on we could either use the cached space pointer that you
added or manage a simple static set of dSpaceIds in the Space class.
This set contains spaceIds of spaces that have the
'mIsDisableInnerCollision' set. Querying this set is a fast lookup
without any pointers involved.

Opinions? (prior to any commits please ;)

cheers,
Markus

[1]
http://ximbiot.com/cvs/wiki/CVS--Concurrent%20Versions%20System%20v1.12.12.1%3A%20Branching%20and%20merging