Floor texture disappears

:information_source: Attention Topic was automatically imported from the old Question2Answer platform.
:bust_in_silhouette: Asked By larvasapiens
:warning: Old Version Published before Godot 3 was released.

Hi godoters, we’re making some experiments with 3D and godot. In certain areas of the map, the textures of the floor (composed of many Quads) start disappearing. Sometimes even the character turns invisible. What could be causing this?

Tests where made with Godot 2.1 and 2.0. Source code can be found here:
https://gitlab.com/larvasapiens/3DPruebas/tree/master