This component is obsolete and its use in filters is not recommended. Use the recent version of the component.
The Selection component provides access to the selection which is currently loaded into Filter Forge. In most graphic editors, the selection is shown as a dotted outline surrounding an area of the image. In Filter Forge, the selection is a grayscale bitmap with selected areas represented by white pixels, deselected areas by black pixels, and 'soft selection' areas by intermediate levels of gray. Selection is a map component, it can be located in the External category on the Components Bar.
When Filter Forge is running as a plugin, Selection reflects the current selection in the host application (such as Adobe Photoshop, Corel PhotoPaint, etc.). When Filter Forge is running in the standalone mode, the selection can be loaded from an image file via the "File > Open Selection" menu command. The dimensions of the selection image must match the dimensions of the original image. If a color image is loaded as a selection, it will be converted to grayscale.
When a filter includes the Selection component but nothing is selected in the host application, or no selection is loaded via the "File > Open Selection" menu command, the component outputs a white image. In this case Filter Forge shows a notification message 'This filter requires a selection' in the filter preview area.
Unlike other components, the Selection component is not affected by the global parameter Size in Filter Controls. However, when this component is used in the subtree of the Height input of the Result component, the value of the Size slider affects the direction of the resulting surface normals, which in turn affects the lighting and the perceived height of the rendered surface. You should keep this in mind when designing filters that use the Selection component in the height map.
The internal precision of the selection bitmap in the plugin version of Filter Forge is currently limited to 8 bit per pixel. This is not a problem in the majority of cases, but may be important when you use soft selections. If you need higher precision for the selection (16 bit per pixel or higher), you can run Filter Forge in the standalone mode and load the selection via the "File > Open Selection" menu command as a 16-bit PNG, 16- or 32-bit TIFF, OpenEXR or a PFM image.
A filter can have multiple Selection components, but all of them will output the same image. Any filter that includes the Selection component is automatically classed as an Effect Filter. For more information, see Filter Classes.
For filters that use the Selection component, Filter Forge does not automatically mask the filter output with the current selection as it does for other filters. For more information, see How Selection Affects Filter Output.
