This guide is actually the second part of the guide - the first part can be found in the Python-Fu Plug-ins board.
If you are familiar with the lighting plug-in then you will feel comfortable with using the lighting options from the dialog. If you are a new user of the lighting filter and feel over-whelmed at the number of options to use then this section of the guide may be of use to you. In order to see the effects of changes more clearly I have used, where necessary, a plain orange square instead of a real character.
Dialog options that are used for the Lighting plug-in parameters
Dialog Option#1: Light colour
With the option set to ‘Yes’ the filter uses the currently selected foreground colour.
Light colours used below on orange; from the left white, yellow, red, green, blue, purple and black.
Dialog Option #2: Type of light source
The Lighting plug-in uses two types of light – point and directional, but to be honest there is not a lot of difference between the two (point on the left, directional on the right).
Dialog Option #3: Direction/postion of the light source
To save space I have combined the six (x,y,z) options in the original filter by presenting them as compass positions which I feel is enough for use with custom fonts. The image below gives a rough idea of how (directional) light will be applied to a layer.
Dialog Option #4: Distance of light source from the centre of the layer
A distance of 0.0 will position the light source at the centre of the layer (not necessarily at the centre of the character). The use of small increments (and small numbers) is recommended for this option when experimenting with values. The image below uses directional light set at an elevation of 0.5 with the following values for distance: From the left 0.0, 2.0 5.0 and 10.0. The most interesting effects on textured surfaces seem to be produced in the range 0.0 to 2.0.
Dialog Option #5: Elevation of light source
This value can have a dramatic effect when the light source falls on bump-mapped textures with light and dark areas. The illustrations below show a light source at elevations between 0.1 and 0.4.
And here the elevation has been set with values of 0.5, 1.0, 10.0 and 100.0. I have found that the most interesting results have been produced in the range of 0.1 to 10.0.
Dialog Option #6: Intensity of light
This option influences the regions that lie outside those directly affected by the light source and if your chosen values produce dark results increasing the value of this parameter can significantly lighten an image. The use of small increments (and small numbers) is also recommended when experimenting with values. The image below using a yellow light source illustrate changes in steps of 0.1 – beginning with a value of 0.1 and ending with 0.5.
In the following image higher intensity values have been used – 2.0, 5.0 and 10.0.
The next three dialog options refer to parameters on the materials tab of the original lighting plug-in dialog. I have not included an option to adjust the ‘bright’ material parameter - it appears to make no difference when called in non-interactive mode.
Dialog Option #7: Glow
This parameter controls the amount of image to show where no direct light falls. The following images use the default settings (but with a bumpmap depth of 15 – option #13
) and then only the ‘Glow’ parameter being increased. Below ‘Glow’ values of 0.0, 0.1 and 0.2.
Below with ‘Glow’ values of 0.3, 0.4 and 0.5.
Dialog Option #8: Shiny
This parameter controls the intensity of the highlight.
Below the ‘Shiny’ values are 0.0, 0.1, 0.2, and 0.5 ...
… and below they are set at 1.0, 2.0 and 5.0.
Dialog Option #9: Polished
This parameter controls the ‘focus’ of the highlight. Just as you get into the mind-set of using small values and making small adjustments the ‘Polished’ option comes along to throw a spanner in the works. This parameter seems to work in the opposite way – in fact the default value in the original plug-in is set at 27.0.
Below the values range (in steps of 5) from 0 to 15.
Below the values used are 20, 25, 30 and 50.
Dialog Option #13: Bumpmap depth
This option sets the value for the bump-map that will be applied to the environment layer to produce varying degrees of light and shadow in an image – a higher value creates greater amounts of both. I have added three other options that influence the effect of the bump-map.
Dialog Option #11
simply turns the bump-map effect on or off.
Dialog Option #14
sets the amount of blur to use with the bump-map when applied to the environment layer (as well as controlling how much blur should be applied to the original character bump-map).
Dialog Option #12
sets the order of blurring and bump-mapping applied to the environment layer.
All this may sound confusing so the next two examples may help.
The first example shows the default values with a blur of 10.0 using ‘Bump after blurring’: The ‘Bumpmap depth’ values are 2.0, 5.0, 10.0 and 20.0.
The second example uses exactly the same values but with the order changed to ‘Bump before blurring’ in dialog option #12
giving a slightly softer, less defined effect. It does, however, depend upon the environment layer used by the filter so it is worth trying the different options.
Other dialog options
These are the options that are not used as parameters for the lighting plug-in.
Dialog Option #10: Shade of grey to use with character bumpmap layer
This option can influence how much of an emboss is applied to a character – darker greys produce a more pronounced bevel effect at the edges of a character. The example below uses a blur amount of 30.0 to set the size of the embossed edge and the greys range from 1(i.e. black) to 5 (mid-grey). The first one (using black) should probably have the light intensity increased to lighten the gold sparkle effect.
Dialog Option #16: Apply a lens
In order to add some distortion to the final appearance of the characters the filter can use this Gimp plug-in by setting a refraction index with dialog option #17
. The first image below uses no lens and then adds lenses with a larger refraction index increasing in steps of 0.5 from an initial 1.0 to 2.5.
Dialog Option #18: Apply polar coordinates
This uses the Gimp Polar coords plug-in to deform the environment layer before applying it to a character. The original environment layer is on the left and the deformed one is on the right.
Dialog Option #20: Artifact blur options
This option makes use of Gimp’s selective gaussian blur filter to attempt to remove noise or artifacts created in the embossing stage of the process. Adjust the Delta value until you get the result you want but avoid high blur values unless you like waiting around for a long, long time.
Dialog Options #21-22: Overlay existing characters
This is really an experimental option that I will try to improve in future versions – I wanted to try and use more than one light source and overlay different lighting effects on top of one another – but the results are rather dark and bland at the moment. Try changing modes to improve the results if you are interested.