The GameMasters Toolkit Humble for Unity, Godot and Unreal Engine:
https://www.humblebundle.com/software...

This humble bundle is a collection of 3D assets, 3D environments and tutorials for Unreal Engine, Unity and the Godot game engine. While some assets are only for Unreal Engine or Unity, many are available for both via Leartes Cosmos, including for multiple Unity pipelines. Additionally Unreal (and to a lesser degree Unity) assets can easily be exported to Blender or Godot or any other game engine, check out our guides below.

Links
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https://www.humblebundle.com/software...
https://gamefromscratch.com/gamemaste...

Asset Exporting Guides
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Unreal to Godot, Blender or Unity:
https://gamefromscratch.com/exporting...

Various guides for using Unity Assets outside of Unity
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Moving to and from Unity:
https://gamefromscratch.com/moving-fr...

Unity to Godot:
https://gamefromscratch.com/move-from...

Finally a guide on the legality of it all:
Is it Legal?:
https://gamefromscratch.com/using-ass...



Timeline:
0:00 The GameMasters Toolkit Humble Bundle Intro
0:09 Bundle Overview
0:48 Bowling Alley Environment in UE 5.3
1:22 Bowling Alley Environment in Blender
1:45 Bowling Alley Environment in Godot Game Engine
2:20 City Mega Environment Demo
3:04 Museum Environment in Unreal Engine
3:30 Museum Environment in Unity HDRP Pipeline
4:22 Godot Tutorial Demo, Overview and Caveats
5:25 GameMasters Toolkit Bundle in Depth
8:25 Redemption on the Leartes Cosmos "Store"
10:25 Conclusion and Outro

The above links may contain a code that enables you to direct a portion of your purchase to support GFS (and thanks so much if you do!).