In my testing; I have made a model and I would like to “add” a geometry to be used specifically for “physics only” and I have a couple quesitons if I may?
In my model the idea is to have the physics be basically a cude or a sphere that would completely encapsulate the actual model inside it. Think of those bouncing balls at toy stores that are clear and contain a colorful object inside:
MyModel.mdl
'----Outter-Most-Physics-Only-Geometry
'----Geometry1
'----Geometry2
'----Geometry3
'----Geometry_n
1: How to tell Urho3D to use that specific “phsics geometry” for the physics calculations? ( and ONLY use that specific geometry for physics calculations and not use any other geometry in the .mdl ) ?
2: I am thinking about setting a material to this “physics only” geometry to be 100% transparent – but do i ‘have’ to do that or should I just leave it with-out a material ?
?
Edit: Essentially; I want “Bullet Physics” to do it’s calculations on the outside object ( ball, box, capsule, whatever… ) but have the “Renderer” render the inside geometry while ‘ignoring’ the outside physics shape… I hope i’m making sence because as normal and simple as this seems; i appear to be a little lost 
Edit: I mean is it something simple like just naming my “physics-only-geometry” something specific like “BulletPhysicsONLY” ?
Edit: Another way of looking at this is the idea that we could have say a “ghost” character and have ‘only’ the hands, feet, and head ( these would all be separate geometries ) be detected by the physics system but leave the other parts not detected by the physics. This sounds crazy but would actually make for a pretty good ghost game in which all your attacks go through the ghost character but when they hit or kick you ( or other objects ) then the physics reacts on you/the environment and if you hit them then the physics reacts on them… You could even design such a ghost game that you ‘have’ to destroy all the physics parts ( hands, feet, head ) to beat the character ( maybe a boss character )…
So I have some ideas …
