RG Shadow plugin: 2D Transform group
This 2D Transform group controls the generation of the shadow in terms of location, size and bounding box. These are controls that you may not use often, unless you run into some difficulty with the way the shadow is behaving (or... misbehaving).
Quality pop-up
There are three Quality settings for final output: Low, Medium, and High. Let's look at examples of the two settings you will generally use, Low and Medium.
Low: This option is point sampled so it's a very fast render, but the results are a little blotchy and pixelated, as you can see from our close-up below.
Medium: This option gives nice-looking results and runs fairly fast. You can work at this Quality option most of the time.
High: The results doesn't look much different than Medium Quality, and its increased render time means it doesn't need to be used very often. High mode isn't needed unless your shadow is doing a really exaggerated Bend, and the render needs to add in more fine detail. (See Bend group.)
Zoom
This control zooms into the shadow. The zoom increases or decreases the shadow's size relative to the source image. This is great for situations in which you want an exaggerated shadow size; for instance, a mouse casts a shadow against a far wall, and the shadow is noticeably larger than the mouse figure.
Zoom is a pretty sensitive slider. It's set to 1 by default. Lower values shrink the shadow, while higher values make the shadow larger. Be careful with Zoom, because a high value can cut the shadow off at the baseline, which may not be what you are looking for artistically.
Translate
The Translate control lets you move the center point of the shadow itself. This in turn moves the entire shadow away from the source object. It's as if your shadow unhooked its feet from yours and danced away. Translate is a great way to animate the whole shadow moving off (as if the light source that casts the shadow is fading out into the distance) without moving the source layer at all.
Transform has separate values for X and Y. By default, the Translate points X and Y starts in the center of the image. This means the image layer and shadow centerpoints match up by default. Once the Transform values are changed, the Transform centerpoint is no longer in the center. This means the layer's center point and the shadow's centerpoint are no longer aligned. The layer centerpoint is not affected by the movement of the Translate value.
The source image is always the default center of the Translate centerpoint. This is true even if a transformation outside of the plugin, like scaling, has been applied to the source layer.
In our stopwatch image below, the size of the image is 1000 x 750. The Translate point defaults to 500, 375, which is the exact center of the image. Let's say that we scale down the source layer in the Timeline to 80% of its original size, making the layer's new dimensions 800 x 600. The Translate point will still default to the center of 1000 x 750.
Grow Bounds
Grow Bounds expands the boundaries of the shadow itself, as if it's making a larger bounding box for the source object. The size of the shadow area grows in pixels. If Grow Bounds is set to 20, then the boundary increases by 20 pixels, with 10 pixels added to each side. At 200, Grow Bounds is creating an extra 200 pixels with 100 extra pixels along each side.
Grow Bounds is a terrific control to have around. Sometimes an image won't have enough pixels to render the entire shadow, and the shadow will appear cut off at the edge of the layer. Increasing Grow Bounds lets the image breath and show its shadow more fully.
NOTE: It's best to keep Grow Bounds to reasonable values when possible, like under 300. Currently, using Grow Bounds will change some of your other settings. For instance, raising the Grow Bounds value makes the shadow take on increased softness. This will result in a slightly different look. The simple workaround for now is to just reduce the Softness level accordingly. We do plan to address this issue in our next product update.
Grow Bounds has a relationship to the Zoom and Translate controls in the 2D Transform group. If you increase the size of the shadow with Zoom, the shadow will soon get cut of by the source graphic's bounding box. Increasing the Grow Bounds value will reveal more of the shadow.
Grow Bounds also affects the 3D Transform> Light setting. The Light setting (Frontlit or Backlit) determines where the shadow begins along the baseline of the source image. The shadow gets clipped at this base point. Even though you increase the boundaries with Grow Bounds, you're still cutting the shadow at the very edge of the image itself. Moving the baseline down means you allow the plugin to build extra pixels around it.
Something to note is that if you have more 'white space' around the source image, then you may not need Grow Bounds. If you look at our stopwatch image below, we have imported it twice. One import has a 1,200 pixel canvas; the other has an 800 pixel canvas. The watch image is the same size in each graphic. The import with the larger canvas area and additional white space surrounding the image has more room for the shadow to render. Therefore, we didn't need Grow Bounds for the 1,200 pixel graphic.