Lifetime checks for stored `RIDs` for collision objects assumed they had valid `object_ids`.
It turns out that some are not derived from `Object` and thus checking `ObjectDB` returns false for some valid `RIDs`.
To account for this we only perform lifetime checks on valid `object_ids`.
* Move client interpolation pump to earlier in the iteration before 3D physics synced
* Allow `get_global_transform_interpolated()` to prime the client interpolation inside a physics tick
* Moves 3D Camera interpolation scene side.
* Automatically switches `get_camera_transform()` to report interpolated transform during `_process()`.
* Fixes `ClippedCamera` to work with physics interpolation.
* NOTIFICATION_MOVED_IN_PARENT makes node children management very inefficient.
* Replaced by a NOTIFICATION_CHILD_ORDER_CHANGED (and children_changed signal).
* Most of the previous tasks carried out by NOTIFICATION_MOVED_IN_PARENT are now done not more than a single time per frame.
This PR breaks compatibility (although this notification was very rarely used, even within the engine), but provides an alternate way to do the same.
It turns out `NOTIFICATION_TRANSFORM_CHANGED` is deferred for these nodes, which can mean the transform is not set in the `VisualServer` until after the reset has been sent, even if the transform is set before the reset in script. This prevented the reset from acting correctly.
Here we explicitly set the transform prior to each reset, to ensure the `VisualServer` is up to date.
Physics body previously stored the RID of a collision object and accessed it on the next frame, leading to a crash if the object had been deleted.
This PR stores the ObjectID in addition to the RID, and checks the object still exists prior to access.
`set_portal_active()` was being called loading packed scenes prior to entering the tree, visual server portals had not been fully created at this point hence the call was being ignored with an error flagged.
This PR defers the call until after entering the tree.
This fixes a minor bug whereby facecount was actually returning the facecount * 3.
There were no major problems from this, but it did mean the optional threshold poly count used when merging was out by a factor of 3.
Add scene side discrete level of detail.
New node `LOD` for UI, and `LODManager` within `World` for automatically updating child visibilities based on distance from cameras.