Terrible performance in the editor when the root part is procedural

[JonnyOThan]

I was helping someone diagnose some bad performance in the editor. If the root part of the craft is a procedural part, the dragcubetool logic will clone and destroy the entire vessel any time a part is modified. This occurs because the vesselcomponent gets added to the root part, and has a list of all the parts on the vessel.

This could be the root (heh) cause of #273 as well - because the entire vessel is being created and destroyed, any error messages associated with different parts will also be re-emitted to the log, producing lots of red herrings.

[JonnyOThan]

As @gotmachine points out, there is no vessel in the editor scene, so that's probably not the underlying issue - but it could be this: https://github.com/KSP-RO/ProceduralParts/blob/10b32eb12f5ecbe9e7f28950023c18c5e730b4ba/Source/ProceduralTools/DragCubeTool.cs#L34

[DRVeyl]

IIRC, this specific code line is to enforce not generating the drag cubes until the part is actually attached to something. You get really bad problems when you allow the drag cubes to generate while the part is in the ghosted state. Mainly, you get the parts flickering attached and ghosted -- most noticeable when attaching a procedural part in symmetry. Or, well, it would be if that line weren't present.

[JonnyOThan]

According to Gotmachine, parts in the editor are actually attached in the Unity parent/child sense, so cloning a part will instantiate the entire part subtree.

[siimav]

341 should fix this weirdness