Effects & CoreImage
|Click on a menu title above for a detailed explanation of that menu's commands.|
|Effects are vector and bitmap operations performed on an Intaglio graphic object to produce an image you can't get by vector operations alone. For example, to get a circle with a drop shadow you might create a blurry bitmap of the circle outline and draw it under, and slightly offset from the circle. This is what Intaglio effects do automatically.
Standard Intaglio effects require at least Mac OS X 10.3 (Panther). If you have Mac OS X 10.4 (Tiger) and a compatible video card you can also used advanced effects based on Apple's CoreImage technology.
Since effects require vector graphics to be converted to bitmaps, Intaglio uses the document's resolution to determine the size of the bitmaps to create. It's important to note that your vector graphics remain editable when effects are used, but the effect bitmaps must be recreated when a graphic is edited. Since this can be time consuming on slower machines or with high resolutions, there are two ways to reduce this computation time while editing. The first is to hide all effects, and the second is to preview effects on the screen at low resolution while editing.
CoreImage is an innovative graphics technology in Mac OS X 10.4 to use today's advanced graphics cards for image processing. Intaglio allows you to use CoreImage to create effects limited only by your graphics hardware and your imagination. Computers with less capable video cards are able to use many CoreImage features, but performance is slower and experience indicates that some features behave in unpredictable ways.
CoreImage includes many different image processing filters called image units. To use these filters show the advanced effects from the action menu in the effects inspector. This will add the still image filters installed on your computer to the Add Effects menu (i.e., the “+”) in the inspector window.
The CoreImage sample above shows one graphic used as a source for another. A “light ball” is mapped onto a 3D surface generated from a text block. The light ball is a plain bitmap image in the document that presents several light sources. The effect also includes two drop shadows to emphasize the green and red lights on the ball. The list in the inspector window shows the filters used to create this effect. The filters at the bottom of the list are performed before those above them in the list. This means the filters at the top of the list are drawn on top of the filters below them in the list. Filters can be dragged in the list to reorder them.
Each filter has an output and zero or more inputs (i.e., sources). Frequently as in this example, multiple filters are chained together by connecting the output of the first to the input of the second, and so on. Filter sources can be the output of previous filters (including “generator” filters) or a graphic in the document previous added to the source list. In this example the Shaded Material filter uses the light ball graphic as its Shading Image input. There are several output channels available to contain intermediate results, to be combined in later filters. Here the output of the Shaded Material filter is stored in channel A, then used as the input of both Drop Shadow filters. The outputs of the two Drop Shadow filters are composited together to form the final image. The diagram below shows the chain of filters used in the image above and the intermediate results throughout the process. The filters in the effects list above are show in the right column of the diagram below.
Below a Circle Splash Distortion filter has been composited prior to the drop shadows and darkened with a Gamma Adjust filter. Note that the drop shadows don't change because they're also using the intermediate result of the Shaded Material filter as their input. The results of all filters above Shaded Material are composited together to form the final image.