GECS Level Spawner & Entity Pooling in Godot 4.3+

Manage entity lifecycles across scenes and handle high-volume unit spawning in GECS v9. A common architectural issue in Godot + ECS is tearing down the entire World during level switches, or encountering garbage collection spikes when spawning hundreds of bullets or swarm enemies. This skill establishes the standard patterns for zero-reboot level transitions, in-place entity pooling, and Nodeless MultiMesh rendering for 10,000+ simultaneous units.

Addon: GECS · version v9 · Godot 4.3+ · MIT
Related skills: gecs-core for setup, gecs-world-architecture for world lifecycle, gecs-performance for pooling benchmarks.

1. Zero-Reboot Level Transitions

In Godot, calling get_tree().change_scene_to_file() tears down the root scene tree, destroying the ECS World unless it is structured properly.

Architectural Rule:

Keep World in the persistent Root/Main controller, and swap only the level environment scenes.