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Gimp around in 80 minutes

Handling Glass, Water and Reflections

Glass and water effects are usually one of the hardest things one can try to set about, but with a little help from Gimp, you're halfway there.

The Wet look Adding water For the Wet Unix label I used a photo of waterdrops on a solid blue background. I desaturated it and made a duplicate to create a highlight and a shadow layer. This was achieved by adjusting the tonal range with Image/Levels as described in page x. To create the illusion of water, I needed to displace the background where the drops were, so I opened a new Channel and painted a mask for the drops. The channel selection was loaded on a black layer which I called Displace layer, and the drop shapes were filled with a b/w shapeburst gradient... Making rain I used a nice, clean photo of a mountain top as background image, and added a little fog with a FG to Transparent gradient. To stylize and add some wetness to the image I created a rain layer. This layer was filled with the custom Rain pattern, darkened somewhat and set in Addition Mode. A text layer was also added. Then I ran the displace filter on the text and the mountain background, using the Displace layer with the drops. Displacing along a curve To make the label fit the bottle shape, I made a new displacement map with the gradient editor (dark to the left and right and bright in the middle to make a round displacement). After displacing the label, the displacement map was used to add a metallic sheen to the label by setting it in Overlay Mode. The final adjustments were made with the Transform/Perspective tool.

How to empty a bottle of wine Cloning away unwanted parts The bottle was made from a photo of a decanter filled with dark red wine. This was a bit troublesome because I wanted the bottle to be empty, or at least filled with some transparent liquid. The wine glass which was visible behind the bottle was easily cloned away, but the rest was left alone, most of it would be covered by the label anyway. Making a dark and bright layer The bottle was cut out, rotated and pasted to a transparent layer. A highlight and shadow bottle was created with Levels, (but not desaturated) and the highlight bottle was allowed to keep a quite large range of shades, otherwise the reflections in the glass would look too hard and unnatural. Recreating missing parts To cover the flat and dull looking part of the bottle (where the wine was) the bottom part was recreated by cloning different parts of the highlight bottle and set this layer to Screen Mode. The shadow bottle was set to Multiply.

Glass Distortion The background, a photo of a lake, was blurred to create the illusion of distance, and to keep the focus on the bottle. The highlight bottle was used twice as a displacement map on the background so that the rocks in the background would appear to be distorted through the curved glass. Rectifying banding Because the lake image was originally indexed, the sky looked banded and ugly. This was rectified by feather selecting the sky, and replacing it with a linear gradient. A few clouds and a sun reflex was also added. Reflections The water reflection was made by flipping the image of the merged bottle to a copy of the lower part of the lake, blurring it, adding some ripples with Distort/Ripple and lowering the opacity level. The waterline (where bottle meets water) was a little trickier and had to be painted by hand in a couple of Overlay layers, and some water glitter was created with the sparkle filter. A white haze was added to the foreground, and of course, a couple of Larry Ewing's adorable Linux penguins.

The Gimp User Manual
Last modified: 19 May 1998