Add framework for supporting geometrical occluders within rooms, and add support for sphere occluders.
Includes gizmos for editing.
They also work outside the portal system.
Fixed a bug in the complex PVS generation which was causing recursive loop.
Move some of the settings out of RoomManager into Project Settings.
Allow PVS generation method to be selected from Project Settings, and control PVS logging.
The existing tracing routine for building the PVS was rather simple compared to the main portal tracing, and could not correctly cope with paths that went through multiple portals from room A to B, and as a result would sometimes miss room entries in the PVS resulting in too many culled rooms in these circumstances.
This PR adds an improved function that can cope with entering a room multiple times during a trace. As a result it has to take care of portal directions (to prevent going back on itself) in a similar, but not identical way to the main portal tracing routine, and internal rooms, to prevent recursive loops.
In some situations looking out from an internal room it was possible to look back into the portal into the internal room.
This PR fixes this by keeping a single item 'stack' record of the last external room, and preventing recursing into this room. This also makes tracing significantly more efficient out of internal rooms, as there is no need to trace the external room multiple times.
When using the preview camera feature it turns out as well as culling the game objects, this also culls the editor gizmos from the preview camera, which makes the editor hard to use in this mode.
To get around this problem we simply disable frustum culling for GLOBAL portal_mode objects when in preview camera mode. This could be a bit slower in an editor scene with lots of gizmos but is the simplest way of solving the problem.
Portal margins were not being correctly sent to the PortalRenderer from the SceneTree, so all margins were being used as default (1.0). This PR fixes this.
It turned out the new autolinking feature was linking portals AFTER the static meshes had been added to rooms in the PortalRenderer. This meant that large meshes weren't being sprawled across these portals. The fix involves doing the autolinking BEFORE adding the static meshes.
Fixes a bug in the warning for portals being in the wrong direction, they should have only been checkout for outgoing portals. This was resulting in erroneous warnings.
Also the room conversion logs are refined to be more compact and informative.
A warning icon is also added in the gizmo for portals where autolink fails.
