Although there is some bug in the Lighting Effects code:
The Filter "Lighting Effects" crashes when I use a channel as Bumpmap
https://gitlab.gnome.org/GNOME/gimp/-/issues/5305
I provide a version with a larger preview.

My solution (before compilation):
In file lighting-preview.h (line 20-21)

replace:



to:



As Migf1 (viewtopic.php?f=9&t=18552#p253325) rightly pointed out in Gimpressionist, the preview distorts the aspect ratio of the original due to the use of only one parameter (PREVIEWSIZE) in the original code - here are two: PREVIEW_WIDTH, PREVIEW_HEIGHT - and this problem does not occur.

Example:
http://www.home.unix-ag.org/simon/gimp/golden.html

Thank you!
Works perfectly ... Linux Mint 19.2 - GIMP 2.10.20 flatpak

Thank you MareroQ!
Tested on Win10 Gimp 2.10.20, works perfectly. Trying later on Linux.

I'm not sure I understand. What part of the Lighting Effects plugin crashes? I use Windows 10 64 bit and it works fine for me.

Hi Mackenzieh.

This is a complicated problem, so let the Gimp developers try to solve it.
Have you tried to follow the bug reproduction steps (listed in Issues # 5305) - for me also in step 12 Lighting Effects crashes.
Also in the Samj version for Gimp-2.10.20 - in the comments - a bug has been reported using bump maps for Lighting.
I suspect is that two parameters in the bump-map have changed - but these new parameters have not been adjusted in Lighting Effects (by analogy - because this change "broke" some plugins and scripts that use parameters bump-map: waterlevel and ambient > 1).
Apart from this problem, Lighting Effects works well.

No, I haven't tried reproducing the steps but I have it book marked, so that I can try it later.

Just a note in case anyone else may have this issue. [No, Neuronoob, just you ...]

GIMP 2.10.20 on Windows 10 64-bit. Downloaded the Big Preview version of Lighting Effects [485 kB]. Found the older version [106 kB] where I expected it: in my Windows user plug-ins folder, where I keep separately downloaded plug-ins. Replaced the old version with the new one. The new plug-in worked the same as the old one, but there was no enlarged preview.

Tried-this-tried-that long story short: I found in the GIMP2 LIB GIMP 2.0 PLUG-INS folder another "Lighting" folder with another version of the plug-in [189 kB and dated June 10, 2020]. I assume it came with the recent GIMP .20 update. THIS was the version I had been using, not the one in my user folder.

When I replaced the old LIB version with the new version, everything, including the preview, worked fine.

But I assume the BIG PREVIEW version will/may be routinely replaced in the next GIMP update.

Hi Neurolurker.

Thank you for your additional comments - this it can always be useful.