What the Heck Happened to the Gimp Stencil Chrome filter?

Hello everyone, David here trying to get some insight into how a staple Gimp filter has turned into a broken mess. Right now as some have noticed I have been re-recording and updating my old Gimp tutorials on my Youtube channel since many are outdated and impossible to follow.

The next one in need of an update is ‘How to Make a Jewelry Style Logo/Text’ however I have run into a problem. For this effect to work we use the Stencil Chrome filter to create the metallic border before adding the gemstone center.

To demonstrate the issue, here is a quick example:

We start with a grayscale image like this one.

We then apply the Stencil Chrome filter, we’re leaving the settings at default values.

The result is an image with 4 Layers: a textured background, a drop shadow, the highlight (gold) layer, and the chrome layer.

Here is where the problem occurs. For comparison here are 4 images.

The first is with Gimp 2.4 and it is what the image should produce.

As you can see it takes the white pixels and turns it into a metallic gray with a gold border.

The second example is with Gimp 2.6.

This is very similar to the 2.4 image with some slight changes in the reflection’s displacement. This is still an acceptable result.

Now, we try 2.8 and the first problem pops up.

The gold border is completely missing, as the layer masks for the grey metal and the gold metal are exactly the same, instead of the gold mask’s being slightly grown for the border.

BUT… the problem gets EVEN WORSE! Let’s look at the monstrosity that is Gimp 2.10.

I… I don’t… ugh, what is this?

Here are the 2 immediate issues that I can see just from looking at the layers.

  1. Both the chrome and the highlight layers have been blown out with a high exposure resulting in too many empty areas that have no shadows/reflections.

  2. The border on the highlight layer has been grown by an absurd amount instead of only a few pixels. This also obscures the drop shadow.

Since so much of the code has changed and I only know how to make minor edits I come to you guys for assistance. I’ve created a side by side comparison for anyone who knows how to fully read script-fu.

Thanks in advance if you can solve the mystery. :wink:

Open an issue in the GIMP bug tracker: