### Changing the Settings Each level, the seven stroke map levels and the media level, is selected with the level selection controls. Simply click on the layer you want to change. For each level, the Media File Section shows the file used. We'll start by ignoring the Media level for the time being and looking at the different stroke levels.
Media File Section Controls
The Media File Section shows the Stroke Map .bmp file used for the selected level. To change the stroke map file, click the file selector button to the right of the filename. This will show a file selector window where you can browse your computer for any suitable image file to use a stroke map. NOTE: The Sketcher plugin uses uncompressed, greyscale bitmaps for all stroke maps and papers. Be sure you only select valid .bmp files. Underneath the filename is a % Scaling slider which allows the shrinking of the stroke map image with the usual effect of increasing the density of the strokes. Underneath the media file section are controls affecting how the stroke map is applied.
Level Specific Controls
All controls set a value as a percentage. To understand how these work, you need to think about how the stroke map is applied. Here's that image of the stroke map used to create level 1 of the previous sketch example.
Stroke Map (PencilA.bmp) | Source Intensity | Level 1
You'll see that this stroke map was applied across the whole image, getting darker in areas of shade. The strokes get darker from areas of lightness to areas of shade, reaching maximum intensity by 50% grey in the source image. At maximum stroke intensity when the strokes are darkest, the stroke map is only rendered pale grey. This can be represented in a graph showing the intensity of the stroke map relative to the image intensity. The graph shows that the strokes are not rendered (invisible) where the source image is white the strokes are at most rendered less than 50% intensity; they are never black, only at most medium-pale grey the intensity of the strokes gets progressively greater (darker) from areas of white to areas a little lighter than mid-grey in the source image. In areas darker than this, stroke intensity remains level Now look at level 5 of the same sketch...
Stroke Map (PencilE.bmp) | Source Intensity | Level 5
For level 5, the stroke map isn't applied until the source intensity is much lower, and the gradation is smooth from grey areas to black areas. The graph for level 5 looks like this This graph shows that the strokes are not rendered (invisible) until the source image is darker than 50% grey the strokes' maximum intensity reaches 100% (black) when rendered darkest the intensity of the strokes increases from areas of grey to areas of black in the source image Each level can therefore be described as a graph of blending value for the stroke map, with a low value, a high value, and a gradient between the two. Trans Start specifies the lightness of the image at which the strokes start to be drawn (the beginning of the gradient from the right). In areas lighter than this percentage value the stroke map is applied at Min Blend intensity Trans End specifies the intensity at which the stroke map is applied at its maximum level (end of the gradient on the left). Where the source image is darker than this, the strokes are applied to their maximum amount, as specified in Max Blend The Min Blend and Max Blend sliders determine the minimum and maximum blending amounts of the stroke map; how intense the strokes are rendered. They range from 0, where the strokes are invisible, to 100 where the strokes are rendered 'black' or with full intensity. Min Blend is how much the strokes are visible in light areas and is usually set to 0. Where Min Blend is higher than 0, the stroke map will always be visible to some degree. The Max Blend is the darkest level the strokes are drawn, set to low values where you want feint strokes such as in the lightest areas of a sketch, and set to higher values where you want darker strokes. For each level, the stroke map and blending character can be set, resulting in the final sketching style. Each level can be deactivated if wanted using the tick box underneath the level selection controls. For example in the provided "NiceSketch.sms" settings the seventh level is not used. This is very useful when setting up your own settings as you can see the result of each level independently.