This is a paid asset, but now you can download Amazing World Fading for FREE, but please remember this package is provided only for learning purposes or to be able to test before buying the product, NOT FOR COMMERCIAL PURPOSES.
Detail this asset from Unity Store: Original Link
Amazing World Fading v2.8
Make game environment volumetric fading around your main character. Bring impressive effect to your game.
Current support 5 kinds of fading effect:
=> Halo.
=> Brightness.
=> Desaturation.
=> Blend two different textures.
=> Stripe pattern.
And 3 kinds of volumetric fading shape:
=> Spherical.
=> Round-XZ, aka infinite height cylinder.
=> Cubic.
All kinds of volumetric fading shape support maximal 4 number of start center position.
Also include an extra dynamic dissolve effect.
=> Spherical and linear shape.
=> Colorful and dynamic edge.
More fading effects will be added in future update.
– Compatible with build-in shading features, PBR, shadow, light-probe, lightmap.
– Compatible with unity free & pro.
– Compatible with mobile platform.
– Compatible with any dx9, dx11 and openGL platform.
– Demo scene and full source code included.