About ambient occlusion

Development Getting Started & Setup
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Hellow

About ambient occlusion

I tried to reproduced this tutorial about ambient occlusion and it failed

Unreal Engine 5 Rendering Ambient Occlusion with Post Process Material - YouTube

May be somebody work with AO - what changes in unreal engine about AO?

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This is short video of reproducing the tutorial steps - may be somebody can find my mistake?

https://youtu.be/e1tDKCM33vg

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On professional forums there are employed experts who replies on all questions - apparently this forum is not professional :(((((