What's supposed to be so special about "Blending" you say? Well, it's "Knowing Your Blend Modes" that is the key to harnessing the power of the Blend component and unleashing its great potential for efficiency unto your filters. Something as simple as choosing the right blend mode at the right time can very much 'make' a filter. Believe it or not, "Blending" is an art form that goes well beyond Blend components, as we shall demonstrate later.
But first, let us explore these blend modes and their usage. The above example shows a simple yet interesting use of the "Lighten" blend mode: Two boring grids of hemispheres are miraculously transformed into a sofa surface! Looks like only the buttons are missing now... ;)
Another example of the "Lighten" blend mode in action, but this time a bit more exciting! What appears to be a rather complex layering of scales is actually achieved in a very economic manner. Without this blend technique one would have to resort to rather tedious masking operations that would likely involve many more components than the above solution.
So what does this "Lighten" blend mode actually do? Well, it compares the values of R, G and B channels for both the foreground and background layers and selects the greater value for each channel. The three selected values are combined into a color to produce the result. As demonstrated by the example above, this blend mode is particularly useful in the creation of complex height maps, as it provides a convenient way to 'merge' height information.
- Helpful filters for studying the use of the "Lighten" blend mode (among many other things!) are:
Here we can observe the "Darken" blend mode at work. As its name would suggest, it is the opposite of the "Lighten" blend mode, as it compares the values of R, G and B channels for both the foreground and background layers and selects the smaller value for each channel. The three selected values are then combined into a color to produce the result. When examined in the context of height map creation, this blend mode acts as a carving operation that 'substracts' from the existing height map. Very useful!
The "Multiply" blend mode in action on two Blend components. This is another mode that comes in handy very often. However, let us examine the Checker component to the right of the two. In this special case, a blend operation with a checker mask was clearly called for. Instead of using the more obvious approach, which would have required an additional checkered mask as an Opacity input for a Blend component, the filter author went for another solution: The Checker component was used to directly combine the two sources, resulting in a solution that requires one component less.
You knew we'd boil this one down even further, didn't you!? Indeed! Let us examine the above example, which reduces the complexity by another two components. To be clear on this, Blend components are among the fastest components in FF, but it is always a thrill to reduce filters down to as few components as possible. The Profile Gradients are definitely there to stay, so this is about as efficient as it gets. As you can see by this example, we have already taken the "Art of Blending" beyond the use of Blend components.
Another example that achieves blending without actually using Blend components: Above we can see a multitude of nested Tiles components. The filter author took advantage of their 'inherent' blend capabilities by chaining them via the Tiles and Mortar map inputs. [Example taken from the Compact Discs filter]
The Threshold component is categorized as an Adjustment component, yet it can provide for very elegant solutions to certain masked blending challenges. The filter construction above is actually inefficient, because the full innate potential of the Threshold has not been taken advantage of. It has indeed been treated as if it were 'just' and Adjustment component, while it could in fact completely replace the Blend! Let's see how this is possible...
In our given scenario, the Threshold component creates a two-color version of a checkered noise field. Noise 'pixels' with a lightness below the Threshold value (as controlled by the Attendance slider) acquire the Low color (black), while those with a lightness above acquire the High color (white). The result constitutes an Opacity mask that was used to control the Blend operation in our initial example above.
Now, if we take advantage of the Low and High map inputs of the Threshold component, we can remove the Blend component altogether! We'll set the alpha value of the Low color swatch to zero and connect the Multiblend directly to the High map input, effectively substituting the black & white pixel field with meaningful image data (i.e. a horde of corporate smilies). Voila! The result is visually identical to what we started with yet more efficient! [Example taken from the Grin Inc. filter]
- Additional Information on this topic: