There are a number of things you need to consider if you wish to guarantee the timing and synchronisation of activities in your publication.
In short, Opus does not restrict what you can and sometimes you can expect too much of some systems. But in those cases, some judicious redesigning so youre not expecting too much of the system, will make all the difference.
Screen redraw some of the functions within Opus taken a second or two to generate for the first time most notably Flare and Shadow effects and some Transition effects. This can impact the timing of these items when they are first drawn.
By default Opus will run through the list of actions in your publication in the order they appear in the Actions Organiser. It will start each action and move on to the next. If there are multiple actions on a single trigger, Opus will also do those in the order they are listed and take account of any delay.
In a Timeline, if the actions are positioned on a single track of the Timeline object, the order will also be guaranteed.
Occasionally system specific events may throw the timing of a publication out very slightly things like loading files from disk, or particularly from CD-Rom or even the speed of the graphics card may impact the timing of a series of actions. If Opus finishes an activity and finds that there are a number of actions that are late Opus will attempt to do them all at once. Even if there are different triggers, Opus will try to d all late actions simultaneously and this can result in a lack of smoothness and a lack of control.
Note:
For example, if you use the Show after option in the Initially Hidden option a lot, or assign actions to lots of On Show triggers this can lead to difficulties with timing.
Put all the key actions on a single track of a Timeline or in the correct order on a single trigger, using the Delay action where necessary.
Design your publication in such a way to ensure that actions are done in appropriate order and that there is an adequate leeway where system specific events might cause problems.
If you have large sound files or video files on a page consider starting other actions on the page via a Synchronise with Start trigger so that Opus waits for the video or sound file to load irrespective of the speed of the system.
You have a page containing a video and a menu of text items animating into place, in a sequence. You could use the Initially Hidden option and then show the menu items using the Show after option. In most cases this will work, but if the system is slow in loading the video the other objects will be delayed, their timings will be off and they may well stutter or cause the video to stutter.
Instead, let the video load and then use the Synchronise to Start trigger to show the other objects in turn if they are also large objects then put in a delay allowing them time to load.
Note:
Each object you add to a page contains a Resources tab in the Object Properties dialog. You can use this to preload resources before the page is displayed this can also help when you are timing events such as sound to images.