UnrealBloomPass

UnrealBloomPass is a post-processing effect used in computer graphics, primarily within the Three.js library, to add a glow or bloom effect to rendered scenes. The effect simulates the phenomenon where bright areas of an image appear to glow and bleed into surrounding regions, enhancing visual realism and aesthetic appeal. This technique is widely employed in video games, virtual reality, and digital art to emphasize luminous objects, create atmospheric effects, or stylize scenes.

The UnrealBloomPass utilizes a multi-step process involving rendering bright parts of the scene to a separate buffer, applying a Gaussian blur, and then combining this blurred image back over the original scene. The key parameters that control its behavior include strength, radius, and threshold. The strength determines the intensity of the bloom, the radius defines the spread or size of the glow, and the threshold specifies the minimum brightness level at which the bloom effect is triggered.

Developed as part of the post-processing pipeline in Three.js, UnrealBloomPass offers a flexible and efficient means to incorporate bloom effects in real-time rendering. Its design allows artists and developers to fine-tune the visual output to match artistic intentions or scene requirements. The effect's name derives from its implementation in Unreal Engine, where a similar technique is used for advanced visual effects.

UnrealBloomPass has become a standard tool in WebGL-based graphics programming for creating vibrant and immersive visual environments. Its adaptability and ease of integration make it popular among developers seeking to enhance scene lighting without significantly impacting performance.