I’m looking for a way to effectively blur a baked lightmap (in 32-bit EXR full-float format). I normally use Photoshop but I’m willing to use other software if that’s what it takes.
In Photoshop when the image is in 32-bit mode, nearly all filters are disabled. Most are only coded to work in 8-bit color depth mode. Some blurs still work, like Gaussian.
While I can still use Gaussian Blur in 32-bit mode, Gaussian causes “bleeding” of the edges of my UV islands. Lens Blur, on the other hand, does not - it’s the only blur filter in Photoshop that I know of that doesn’t have that bleeding issue. Unfortunately Lens Blur doesn’t work on 32-bit images! So I can’t actually use it on my Blender-baked lightmap.
Is there a way (maybe in GIMP or some other software, or even within Blender) to blur the 32-bit lightmap texture without bleeding around the UV edges?
I’ve heard that Smart layers in Photoshop can be used to edit a 32-bit image as if it was in 8-bit mode, allowing me to use Lens Blur. But when I’ve tried it the intensity of the image is clamped as if it had been converted to an 8bit image, essentially ruining the point.
Does anyone have a suggestion? Thank you so much in advance.
P.S. It doesn’t necessarily have to be BLUR. Something like Photoshop’s Reduce Noise filter would do the trick too. I just need something that will get rid of all the noise and fireflies in my Cycles bakes. I can’t render with high samples because my PC sucks.
PhotoLine. PhotoLine doesn’t care whether your image is a 32bpc multi-layered EXR and all adjustment (layers) remain available (in stark contrast compared to Photoshop) and work with 32bpc internally.
Fully functional trial version (30 days) is available at www.pl32.com.
Thanks Herbert. I actually just learned that the latest development version of GIMP, the unstable 2.9 branch, actually opens EXR files, and GIMP’s Noise Reduction (Filters->Enhance->Noise Reduction) filter works fine on them, even in 32-bit mode! I’m amazed that an expensive piece of commercial software like Photoshop can’t do this and yet a totally free program like GIMP can. Bye, Adobe!
If anyone else is interested, you can either build the dev version of GIMP from source, or you can get a Windows build from here. Download links are on the very bottom, lower right of the page. https://www.partha.com/
Note that the current stable build of GIMP WILL NOT work for this. 2.8 can’t even open EXR files. Only the 2.9 development branch can.
Will that version of Gimp open multi-layered EXR files as well? That would be interesting.
Yes, I agree: Photoshop’s core engine is somewhat limited in regards to 32bpc files. My main reason to leave Photoshop were all the small workflow quirks that never got fixed, and still haven’t been fixed.
Then again, it depends on the user’s workflow too. I still don’t understand why Photoshop layers can only have one bitmap mask (using clipping layers instead is really clunky) when applications like PhotoLine, Krita, and Affinity Photo have no such silly limitations.
I don’t think it opens multilayer EXRs yet, but it sounds like it’s in their future plans.
Thanks to Mukund Sivamaran, Rasmus Hahn, and Øyvind Kolås, GIMP now features basic support for OpenEXR files, both loading and exporting. It’s currently missing advanced features such as layered or multiresolution EXR files, or unpremultiplication when exporting etc., but you should be able to load, process, and export a “regular” floating point EXR file just fine.