Image Processing Reference
3.11.6 Lighting Effects—Creating Light
Reflections with Paths, Paintbrushes, or Filters
In the previous exercises, you learned how to use painting tools and some
filters to create highlights and lighting effects to emphasize the sculptural
appearance of objects and to add three-dimensional depth to an image.
When printed on matte surfaces, reflections are more likely to be round and
soft, while on shiny surfaces or glass, reflections tend to gleam and sparkle.
Constructing Light Reflections with Paths
You can also use paths to produce light reflections and highlights. You can
use paths to create small star-shaped paths in the image, which can be
transformed into selections. ( Note : Always duplicate the path first so it
won't be replaced by the selection.) The selections are given a soft border or
feathering and are filled with white color, sometimes repetitively, until the
desired effect is achieved. This is done repetitively so that a filling becomes
visible in very small stars.
Painting Light Reflections with Star-Shaped Paintbrushes
Perhaps you can find a paintbrush on the Internet with the appropriate form.
Use the following keywords for your search: gimp, brushes, reflex, star. Or
browse on one of these websites:
You can also create your own brushes with six spikes in the Brush Editor
(see section 2.7.2) and the settings shown in Figure 3.69 .
Creating Light Reflection with Filters
In addition to graphic and painting techniques, GIMP offers a number of
filters that simulate special lighting situations or simply set highlights and
also can be used to create lens reflections in an image. The Supernova filter
(menu Filters > Light and Shadow > Supernova ) can be used to make radiating
reflections depending on the radius setting. You were introduced to this filter
in section 3.6.5.