Grounded contact shadows for product shots
Derive a soft, tight or floating contact shadow from a transparent product PNG. Three presets, ComfyUI core nodes, no model download.
These are fixed historical examples. The demo does not execute workflows or offer redemption and downloads.
Overview
Where the sticker look comes from
The cutout can be clean and the composite still reads as fake. The usual cause is not the edge; it is the missing contact shadow. A real product leaves a darker area tied to its height, material and key-light direction. Without that area, the product floats.
This workflow derives the shadow from the transparent PNG's alpha. You do not paint a mask by hand.
Three presets
- Soft studio: large radius, low opacity; white or light-grey backdrops
- Tight tabletop: small radius, short offset; desks, stone, wood
- Floating: large offset, softer blur; shoes, bags, levitated display
Pipeline
- 1Load the transparent PNG and center it on 1024 square
- 2Derive the shadow mask from alpha
- 3Blur and offset according to the preset
- 4Composite the shadow, then the product
- 5Save three comparison images
Limits
The shadow direction is a fixed preset; it does not infer the key light. The tutorial shows how to choose the matching preset from the product highlight and the source shadow. If none match, rotate the product 90° or build the shadow in an external tool.
Clean-room graph authored for LatentBay; no third-party workflow JSON, prompts, images, video or prose copied. output license: commercial ComfyUI core: GPL-3.0 (https://github.com/comfyanonymous/ComfyUI)
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Related workflows
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