[Compositor Node Group] Spot Remover (Free)
About
This is a node group for the Compositor Node Editor in Blender/Bforartists that takes hot spots from an EXR (float or half float) image or raw render with a high threshold to remove them. It then blurs the image with the removed spot to get an average colour and fills the spots in again.
This was developed to workaround a fresnel BDSF specular hotspot bug (February - April 2021) in the Principled Shader of Eevee in Blender 2.93 Alpha.
Relevant Bug that causes these issues:
Features
Removes small hot spots in a raw render
Removes small hot spots in an EXR image sequence (float 16 or float 32)
You can change the spot threshold if necessary within the nodegroup.
You can optionally adjust how the spots are filled also.
Instructions
- Download the *.blend
- Append or link the Node Group
- Plug in an EXR image or sequence into the Image In port
- See the results in the Image out
If you want to tune, go into the node group and change the luminance key threshold, this is the sensitivity of the hotspot - it is currently set at 19.9 to 20 energy levels.
Updates
[Ver 2.0.0]
- Added in an energy max, as sometimes the RGB were blown out to NaN (infinity) meaning masking them was impossible with alpha alone. It caused weird artifacts, so I made an energy clamp and improves how it masked the spots.
- I also improved the way the spots would fill with a better blurring technique.
- Marked as an asset for the new asset browswer
[Ver 1.0.0]
- Initial Release
A blend file with a single node group and a test EXR image showing how it works.