Product relight: match a cutout to the scene light

When relighting helps

After compositing, if the product highlight points in a different direction from the scene key light, it reads as pasted. Relighting changes only the product's light, not its shape or position.

Method

1. 1Load the transparent product PNG and center it on 1024 square
2. 2Use alpha as a mask to lock the product area
3. 3Run a low-denoise FLUX.1-schnell pass (0.2–0.3)
4. 4Decode and reattach the original alpha, so the transparent background and silhouette survive
5. 5Save the relit transparent PNG — product pixels come from the low-denoise pass, and text stability depends on denoise

Safe range

0.2–0.3 denoise is the safe range. Above 0.35, packaging text and thin lines start to warp; above 0.5 it is closer to repainting the product and unsuitable for branded goods.

Limits

This is not physically based relighting and cannot change material reflectance. Mirror metal, glass and clear plastic are limited. The tutorial says which categories should be shot for real instead.