Document exporting glTF files from Godot (#5165)

tutorials/assets_pipeline/exporting_3d_scenes.rst

@@ -0,0 +1,30 @@
+.. _doc_exporting_3d_scenes:
+
+Exporting 3D scenes
+===================
+
+Overview
+--------
+
+In Godot it is possible to export 3D scenes as a glTF 2.0 file. You can
+export as a glTF binary (``.glb`` file) or glTF embedded with textures
+(``gltf`` + ``.bin`` + textures). This allows you to create scenes in Godot,
+such as a CSG mesh blockout for a level, export it to clean it up in a
+program such as Blender, and then bring it back into Godot.
+
+.. note:: 
+
+    Only Blender 2.83 and newer can import glTF files exported by Godot.
+
+To export a scene in the editor go to **Project > Tools > Export GLTF...**
+
+.. image:: img/gltf_godot_export.png
+
+Limitations
+-----------
+
+There are several limitations with glTF export.
+
+* No support for exporting particles since their implementation varies across engines.
+* ShaderMaterials cannot be exported.
+* No support for exporting 2D scenes.

tutorials/assets_pipeline/index.rst

@@ -10,4 +10,5 @@ Assets pipeline
    importing_audio_samples
    importing_translations
    importing_scenes
+   exporting_3d_scenes
    escn_exporter/index