Tip #4, Pre- vs. Post-transforms

LM has an interesting concept of pre-transform and post-transform. Put most simply, pre-transforms affect the artwork itself, whereas post transforms are applied just to particular instances of the artwork. This has implications for how LM optimizes SWFs by storing single objects and re-using them in the SWF, as well as for how it stores each object.

When you first import a piece of artwork and scale it, you're applying pre transforms; that is, you're changing the native size of that artwork and therefore (if it exports as a bitmap) the number of pixels it contains. To see this in action, place an image and export, then scale it up and export again. When you set a stopwatch for the scale attribute, you begin to apply post transforms; that is, you're just scaling that particular copy of the artwork. The trick is to find the point at which your artwork appears the largest, then choose Object->Transform->Make Actual Size. Now the native artwork is only as big as it needs to be in that situation, and at other points it will be scaled down and the effects of the scaling won't be so visible. The actual size determines the size required in the SWF.

You can see pre- vs. post-transforms at work by creating a circle and using the 3D palette to apply a 5-pixel bevel (figures 1 & 2) .

FIG 1

FIG 2

Notice that when you pre-transform the circle, the bevel remains 5 pixels (because you're changing the source artwork) (See movie 1).

MOV 1

But when you post-transform the circle, the bevel distance scales with the rest of the circle (because you're transforming that copy of the circle, not the source object) (See movie 2).

MOV 2

Notice also that if you make a small beveled circle and post-transform it by setting a scale stopwatch and scaling it up, you can redefine its native size by choosing Make Actual Size (See movie 3).

MOV 3

Understanding pre- and post-transforms is essential when you want to duplicate animations without blowing up the size of your SWF. Earlier I mentioned that it's possible to save size by wrapping animated elements in a TIG, then applying transformations at the group level. Be aware that if you apply *pre* transforms at the group level to a duplicate TIG, that group will export separately from the original (the artwork it contains still may be stored once, but the animations applied to it will export twice). By setting a stopwatch, duplicating a TIG, and applying a *post* transform to the duplicate, however, you're telling LM that it should keep the underlying artwork the same and scale up just that particular instance of it.

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