blendScreen
Replicates Photoshop's 'Screen' blend mode, providing a soft, non-destructive brightening effect, especially suitable for overlaying textures with black backgrounds.
Core Advantages
Automatically 'keys out' black backgrounds, making it a powerful tool for handling effects textures like glows, fire, and flares. Its brightening effect is softer and more natural than simple addition, avoiding harsh over-exposure and creating a more photographic look.
Common Uses
In post-processing, blending a blurred highlight pass back onto the original image to create a soft glow (Bloom).
Compositing lens flare textures to build complex optical effects.
Adding an environment reflection layer to materials, naturally integrating cubemap colors onto a surface.
Rendering VFX like fire and smoke from sprite sheets with black backgrounds.
How to adjust
The effect is determined by the brightness of the `blend` input. A pure black `blend` is completely neutral (transparent). As `blend` gets brighter, the brightening effect on `base` becomes stronger, but with a smooth falloff. A pure white `blend` results in a pure white output. Consequently, using a blurred glow texture as the `blend` input can create a very natural, diffused glow on the original scene `base`.
Code Examples
1// Softly blend the blurred glow layer back onto the original image to create a bloom effect
2const finalImage = blendScreen( originalScene, blurredGlowLayer );