someone point me in the right direction PLEASE

I'm not sure this is a building question, but maybe someone who can help me understand is reading this forum....

Yesterday I had the chance to try and make some simple objects interact via the physics engine. NO, I'm not going to ask you to do any math... just make something and tell me what is wrong with this picture..

start with a sphere... nothing special.... 0.2 in all three dimensions.... make it PHYSICAL and put it on the ground ( real ground....) not a floor!

Make another sphere, same.... put it on the ground too.

and finally, a third sphere, this one larger.... 1 meter all around...
Dimple begin to .3 and end to .65, then hollow 5.0... make it physical and lay it on the ground.

Not too hard so far.... 3 physical objects on the ground. Look under them and there isn't any "space".....

Take all three objects to a floor.... put them down and look again... there's a GAP under all three.

I can understand a physics engine rule that says there's a minimum distance requirement

http://lslwiki.net/lslwiki/wakka.php?wakka=physics says....

"The minimum distance for objects to avoid collision (the spatial precision), is 0.1m (10cm)--and an error will occur if a prim/object is tried to be made physical but is within 10cm from another prim/object/avatar or the ground."

but jeez.... I just saw 3 things sitting on the ground and they weren't 10cm above it....

Now.... Take the 2x 0.2 meter spheres.. and drop them in the bowl shaped hole you made in the 3rd sphere.. let em sit for a bit and tell me WHY....

The 2x 0.2 meter spheres "float" over the big one... but they will touch each other!

So I have 3 physical things that will touch the ground (despite what the WIKI says), the 2 spheres will touch each other (despite what the wiki says) , but they wont touch the bowl shape.... ?????

Is there any way for a builder to get to pick when the "rules" for prim separation get to be enforced?

I think some of this will become clear when you make the bounding boxes visible in your client (Advanced - Rendering - Info Displays - BBoxes). I don't pretend to understand every detail about how the bounding boxes interact with each other, but it's clear to me that what you see as a rendered shape isn't necessarily what you get in terms of physics, neither with objects nor with the ground. BTW, if you set the Beginning dimple value back to 0, your 2 smaller balls will drop down lower into the bowl.

yes, I've looked at the bounding boxes....and, as I said, I'm willing to accept that they become necessary. What Im really asking is when do they get enforced.. The spheres have the same bounding box whether I drop them on the ground or on a flat prim.

Did you see the bounding box enforced when the sphere was placed on ground? I didnt.....
Did the bounding box disappear when the 2 balls were dumped into the bowl? Nope, still there...., same size as when they are on the ground floating, and enforcing the "float" over the bowl, but completely ignored when it comes to deciding if the spheres will rest against each other... so the question remains, at least for me... When do they get enforced?

Ayep , the collision mesh isn't exactly what you see with the terrain mesh.