@jonathan - et al!
This is in answer to your question about using “Persistent Symbols” for scene changes involving custom transitions with or without animations (“trans-animations”) occurring during the transition.
A question before we move along...
Duplicating the elements is easy from a layout perspective - so I am assuming the above relates to overhead? (Let’s exclude projects with lightweight imperatives such as banner ads.)
Part of the design goal would be to keep the elements involved in the transition to a minimum.
Would duplicating a simple set-up such as headline text (four words); short paragraph; basic SVG (i.e. not a map of the United States); one image 300px x 400px; and eight Hype primitives (ellipses & rectangles) comprise much of a hit? The image would of course be cached.
I know this is similar to asking how long is a piece of string - but just a seat of the pants guess?
For the purposes of this post a “custom” transition is a manually created~directed transition as opposed to the “standard” Hype transitions. For an example of a “custom” transition with “trans-animations” please see the video at the bottom of this post showing an example containing 3 separate trans-animation styles.
1) Video
This is a slam dunk situation for “Persistent Symbols”. Trying to synchronize a trans-Scene video without this valuable feature would be torture. The following example also appeared in another post. Persistant Symbol across Scenes.hype.zip (2.6 MB)
2) Sliders ~ Filmstrips
I am seeing a marginal utility here unless it is just a couple of scenes.
Reason: Suppose we have (5) Scenes all custom transitions. If You are navigating back and forth between all the Scenes where would a "regular" set of elements fit in? To keep the idea of no “repeating elements” going the entire set-up would need to be a Persistent Symbol - so You might as well just have one Scene with Groups serving as frames in the slider.
3) Complex Transitions...
involving destructive pixel operations such as crossfades, or situations where duplicate images are needed to stack over each other to achieve the effect. You would need to duplicate the necessary elements in a Persistent Symbol also.
By no means am I trying to portray the above as an exhaustive examination of the possibilities but rather examples of common situations.
Example: Three separate “trans-animations” during the transition:
Element rotation; “Vertical venetian blind”; Blurred background to sharp...