Great idea! I presume you mean blend modes as in photoshop?
Multiply/Screen/Overlay/Hard light etc?
Darkens or lightens the colors, depending on the blend color. The effect is similar to shining a diffused spotlight on the image. If the blend color (light source) is lighter than 50% gray, the image is lightened as if it were dodged. If the blend color is darker than 50% gray, the image is darkened as if it were burned in. Painting with pure black or white produces a distinctly darker or lighter area, but does not result in pure black or white.
Is there a way i can do this in shaderforge from a grey scale image?
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