This issue has been resolved as of 4.12. Perception is not located in the Editor Preferences, as it is not an experimental feature. You’ll need to add an AI Perception component to your AI Controller, and configure your perception settings on that component. Then, you’ll need to add AI Perception stimuli source components to all actors that you want to be able to be sensed by the AI Character. Keep in mind that pawns are registered as sources by default.
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