All objects ChBodyEasyXXXX also initialize own 'density' field (that is not widely used, though, but it is here, so it is better to initialize it for completeness)
IMPORTANT change in the way that ChSystem does the management of its lists of bodies, links etc. Internally, there are three lists/vectors, that is: one for ChBody items, one for ChLink items, one for all other ChPhysicsItem that are not bodies or links.
Previously, if using the mysystem.Add( myitem) command, the Add() machinery detected in which of these three lists the item had to be put, but it did not take into consideration that someone might have inserted a ChBody-inherited item, so that was add anyway to the list of 'other ChPhysicsItem' stuff.
Indeed, now it works in the following more reasonable way: if one adds a ChBody-inherited item, such as ChBodyEasySphere or such, it will be sent to the list of ChBody.
Change in the PovRay exporter.
The fact that an object must be exported or not does not depends anymore on the old system of having it inserted in the POVray exporter list (that was limiting in some cases, and not coherent with other exporters).
So, now, one can flag that an object must be rendered by adding the new ChPovRayAsset (it is just a lightweight asset that acts as a flag).
IT is still backward compatible because I modified the Add() function accordingly.
Note that one reason for this change is that it should be able to accomodate the situation where particles / objects are deleted in the course of the simulation, and the POV exporter will handle this automatically.
BTW Last minute update: this 'deletion' feature is broken. Must be tested/fixed.