Unable to use a twisted prim for stairs

I encountered this last night. I've made two bug reports about it. Today, I tried to make it again and it still doesn't work.

I'm trying to make a spiral staircase using fewer prims and taking advantage of the new twist options. Once I make these prims, I find that I can't walk along it. Instead I'm bumping into its invisible "boundary box." Someone else saw this too. She recreated the prim I made, and we couldn't walk along that one either. Please help enlighten me on this.

Hmm havent played with this yet...

But maybe the Spiral is too tight for an Av to fit thru....

I'll play with this tonight and see...

I saw your spiral Lash and i walked right thru it like it was phantom..that's happening too much for me too..brand new prims and I walk thru em...

I ran into the same problem during the preview. I, too, bugged it.

I saw this in preview, and showed it to a few Lindens.

Mine was a 10x10x10 meter cube, twisted to the max, and with cut settings of 0.98 and 1.0. The problem is the cut. Back that off to 0.95 or so, and you should be fine. They should be fixing this, since they DO know about it.

I made a spiral staircase using the new prim "Ring". It was 1 prim and worked great. I added 1 prim rails on either side of it. Had no problems using it and could even run up it with the rails on and not fall off. I can give anyone a copy, just IM me in game.

The problem is that the settings on your shape produce an collision object in the physics engine with non-physical properties (such as negative mass, or negative elements in the inertia tensor). This happens when the geometry computed for the shape is bugged such that the volume is not closed (triangle missing) or is inside-out over part of it.

If we allow such objects to become physical, or collide with other moving objects then they can cause instabilities in the physics engine -- causing objects to bounce to infinite velocity in milliseconds.

Unfortunately, we can't use Havok-1's convex-hull algorithm to get a better approximation of the shape because that usually produces a worse shape. So, when this happens we just replace the physical representation with a bounding box and move along.

The problem is that we haven't yet clamped the primitive parameters to keep the shapes physically possible. We need to be more careful about how we construct the triangles that make up the objects.

In the meantime, if you must collide correctly with the object (it isn't merely decoration) then the current workaround is to reduce the hollow and/or twist a little bit until the object is physically viable.