Earthquake Zone

I make a physical ramp out of stone situated on the ground. I make a long physical bar out of metal and rest it on the ramp stretching from the high end of the ramp to the low end of the ramp.

Well, "rest" is what I expected but not what I get. The ramp and the bar jiggle for about 15 seconds as if were an earthquake going on. Due to the vibration, the bar "walks" across the ramp to a random position other than I intended.

1) Anybody know where the vibration is coming from?

I also notice that when the ramp and the bar do finally stop vibrating, the bar is actually floating about 2 inches above the ramp.

2) Since both the ramp and the bar are physical objects, shouldn't the bar be making contact with the ramp?

Doubtless I'm missing some key element of dealing with physical objects but the LSL Wiki hasn't provided me with the clue I need.

Thanks in advance for any insight.

Cheers, Moose

Make the ramp nonphysical, and the problem should stop. What you're seeing is the bar pushing down on the ramp, the ramp then bouncing off the ground and hitting the bar, the bar bouncing up and then falling back down to hit the ramp again, etc, etc, etc. The two objects end up playing bumper ball until they run out of kinetic energy.

The only objects that need physics are those you actually want moving. If you want something to be totally stationary, always make it nonphysical. Unless you make an object phantom,it will always be tangible, so physical objects will still collide with it (which is why your avatar, a physical object itself, can stand on nonphysical objects). Nonphysicals just won't be affected themselves by collisions or by gravity, so they'll stay put, but physical objects will be affected by collisions with them.


This is normal. The collision lattice around each object is aways 10cm larger than the object itself.


Well, yes and no. The objects' collision lattices make contact, but those lattices are graphically invisible. Technically, the lattice is a property of the object, so the objects are in contact; it's just that the part of the object you can see is a little bit smaller than the part that collides.

The 0.1 meter tolerance for the physics engine is the one causing the gap. It does not mean that the gaps are always 0.1 meter. Its just rounded off around those figures and you might see the prims intersect each other sometimes.

Objects do not have a separate invisible collision lattice surrounding itself, which in effect would cause the gap to be even bigger (0.2m ?)

This was an old quote by Andrew.

Thanks very much for the replies. They were spot on.

Cheers, Moose