Bloom in 3D rendering is a visual effect that simulates the natural scattering of intense light, creating a soft, glowing halo around bright light sources or objects. It is achieved through a multi-step process.
First, isolate bright areas: Identify and separate regions in the rendered image with high luminance, such as light sources or reflective surfaces.
Next, blur the bright areas: Apply blurring (often Gaussian blur) to these isolated regions to mimic how light scatters in the atmosphere, softening edges and spreading the light.
Finally, merge with the original image: Combine the blurred bright regions back into the original image, blending them to produce the characteristic glowing effect.
This process enhances realism by replicating human eye perception of bright light, making 3D scenes more immersive.