The developed algorithm of the visual perception system for game agents, implemented in the Unity game engine, is presented. The proposed method is based on the comparison of images from two cameras, taking into account complex visual effects (lighting, shadows, camouflage), and supplemented with line-of-sight verification, taking into account the speed of the object, and the mechanics of gradual detection. Testing of the system has shown a significant increase in realistic detection compared to traditional methods, while maintaining performance within a small additional load on the processor. The algorithm was optimized using Unity Job System and dynamic camera activation. The scientific literature on similar solutions has also been analyzed and their strengths and weaknesses have been identified. The results can be applied in video game development to create realistic behavior of non-player characters, especially in games with stealth elements.