On 2011-07-11, at 23:05, Dahlia Trimble wrote: > One thing I noticed while coding collision geometry for OpenSimulator is as > hollow is increased and prims are twisted or otherwise manipulated such that > the hollow shape doesnt exactly follow the outer shape, the probability > increases that the surfaces formed by the triangles that make up the hollow > shape may actually protrude beyond those that make up the outer surface. I'm > not sure what SL sims do under these conditions but what ODE (Open Dynamics > Engine - most commonly used physics engine in OpenSimulator) is create a > condition where physical objects may become trapped between the resulting > surfaces. ODE uses trimesh colliders and surface normals for determining > collision surfaces and if prim hollow surfaces protrude outside of prim outer > surfaces, the surface normals for these surfaces point in the wrong > direction. This can be alleviated by increasing prim vertex count, but for > some of these prims vertex count may already be even greater than 4000 > vertices. Increasing it further would use excessive memory and likely > increase the cost of computing collisions dramatically. I've found that a > limit of 95% maximum hollow is a good compromise between prim complexity and > usability. > > > On Mon, Jul 11, 2011 at 7:34 PM, Wolfpup Lowenhar <wolfpu...@earthlink.net> > wrote: > This is an automatically generated e-mail. To reply, visit: > http://codereview.secondlife.com/r/388/ > > Review request for Viewer. > By Wolfpup Lowenhar.
Given the possible uses of this capability, it would be acceptable for the physics shape to pin at 95% while the rendered shape is allowed to be thinner. _______________________________________________ Policies and (un)subscribe information available here: http://wiki.secondlife.com/wiki/OpenSource-Dev Please read the policies before posting to keep unmoderated posting privileges
