Why can I not walk through a hole in my mesh?

[Lillith Anatine]

I made a "test room" in blender with no ceiling. It has no ceiling, but has walls, floor, and a doorway opening. After I've uploaded it and rezzed it inworld, I can stand on top of it and I do not fall in like I had assumed I would. I've tried to play with the physics shape but there are no changes possible with a single-prim mesh object. Why can't I enter my room?

[Dilbert Dilweg]

You may find this topic helpful on this very subject.

http://community.secondlife.com/t5/Mesh/Understanding-Physics-with-Builds/m-p/1464037#M13127

You will either have to make separate low LOD pysical objects or make sure you chose "solid" on the physics settings during the upload

[PeterCanessa Oh]

http://community.secondlife.com/t5/Mesh/bd-p/Mesh

[Dianne Melson]

simply because it is not possible to go inside a convex hull mesh object.  It behaves like a solid object even though it looks otherwise

[Pete Spires]

Edit the object, select the Features tab, and change the Physics Shape Type from "Convex hull" to "Prim"