[Opensim-dev] Attached Linksets and Collisions? (on SVN 10029)

[John Sheridan]

Gang,
  Before I plug this into Mantis, I wanted to confirm this with the 
developers.  Recently I've been noticing that after teleporting in or 
attaching something my avatar has been getting bumped / tossed around 
quite a bit.  It occurred to me, that this seems like its typically a 
physical reaction - as if one were to be hit with a physical prim or 
collide into a static prim. So I looked up the top colliders in the 
estate tools and found a whole bunch of colliding prims (~300 in total) 
all at the same location and owned by me.  Which was strange enough on 
its own given the sim was empty of prims other then what was attached to 
my avatar.

  So to test I removed all of my attachments then suddenly the 
collisions cleared.  When I re-attached everything they returned.  To 
dig a bit deeper, I rezzed my hair and shoes to the ground, and found 
that everything was normal, and the physics option was not ticked.  Out 
of curiosity, I set the hair and both shoes to phantom, took them back 
into inventory, then re-attached.  Surprisingly, no more collisions! 

  From the looks of this it seems that when attached, prims are either 
becoming physical and colliding with one another and the avatar, or more 
likely are remaining normal / static and just colliding with the avatar 
since they're not moving or flying haphazardly about as is typical of a 
physical prim when bumped.

  Upon further testing though, I did however discover something rather 
interesting.  So far I've only tested with the skull attachment point, 
but when a single prim is attached it acts normally.  The avatar is not 
bumped when it rezzes and no collisions show in the estate tools.  
However, when two or more prims are linked and then attached the avatar 
is bumped around and it seems that only the prims in the linkset that 
are touching the avatar begin to register collisions within the estate 
tools. 

To reproduce this:

1 - rez a single prim to the ground
2 - take to inventory
3 - attach to skull

 - Check the estate tools and no collisions show.

1 - rez several prims to the ground
2 - link them
3 - take to inventory
4 - attach to skull

 - Check the estate tools and only the prims in the linkset which are 
touching the avatar will show.

1 - re-rez the linkset to the ground
2 - tick the phantom checkbox
3 - take to inventory
4 - attach to skull.

 - Check the state tools and no collisions show.

I wonder if per chance this is related to the recent oddness with logins 
/ teleports / sim crossings where ODE has been going batty? 

Thanks, :)

 - John / Orion Pseudo