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Asked: 2026-05-27T07:42:00+00:00

This is my first time I need to create a cutscene system. I have

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This is my first time I need to create a cutscene system. I have read a lot on the web about different ways to accomplish this task and have mixed them with my own ideas. Now, it is implementation time, but I need some info from other people with more experience than me in this field. Here we go:

1) Some years ago, I implemented a system that actions could be queued in a serial/parallel way, building a tree of actions that when executed created the final result. This can be sure used as the cutscene system director, but, wouldn’t it be so much simple to just have a timeline with actions ran at a certain time? An example:

  • playMp3(0, “Song.mp3)
  • createObject(0, “Ogre”, “Ogre1”)
  • moveObject(1, “Ogre1”, Vector3(100,100,1))

This way everything would be really simple to script. Serial actions are supported buy spreading them correctly in time and parallel actions just need to have shared time ranges.

One problem I have seen is that an action like Sync() (This just waits for all actions to finish before start the other that come afterwards) can’t be used because we’re using absolute time to trigger our actions. Anyway, a solution could be to have our actions layered based on last “sync()”. I mean something like this:

  • playMp3(0, “Song.mp3)
  • createObject(0, “Ogre”, “Ogre1”)
  • moveObject(1, “Ogre1”, Vector3(100,100,1))
  • sync()
  • moveObject(0,….);
  • createObject(1,….);

As you may notice, times after sync() starts again from 0, so, when a sync() is ran, and it determines all previous actions from last sync() are finished, timeLine elapsed time would be 0 again. This can be seen as Little cutscene action groups.

2) The previous explanation needs all actions to be added at the beginning of the cutscene playing. Is this how it usually is done? Or do you usually add actions to the timeline as they are needed?

Well, I could be wrong here, but I think this could be a nice & simple way to lay the actions for a cutscene. What do you think?.

Thanks in advance.

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  1. Editorial Team

    I’ve done a few of these systems. I’ll tell you what I like to use I hope this will answer your questions.

    One of the first cutscenes system I did used LISP dialect because it is just couple of hours work to get a parser working. It used to be something like…

    (play "song1.mp3")
(set "ogre1" (create "ogre"))
(moveTo "ogre1" '(100, 100, 100))
(wait 1)

    I created something like virtual machine (VM) that was processing my scripts. The VM didn’t use separate thread instead it had update function that was executing X amount of instructions or until it hits some synchronization instruction like wait for 1 sec.

    At that time this system had to work on J2ME device which didn’t have XML parser and XML parser was too much code to add. These days I’m using XML for everything except sounds and textures.

    These days I’m using keyframe systems as BRPocock suggested. The problem is that this will be harder to manage without proper tools. If you using already some 3D software for your models I’ll suggest you to investigate the option to use that product. I use Blender for cutscenes for personal projects since it’s free at my work place we use Maya and 3ds Max, but the idea is the same. I export to COLLADA and then I have my animation tracks with keyframes. The problem is that COLLADA format is not the simplest it is made to be flexible and require decent amount of work to extract what you need from it.

    The problem you will have with your format is to describe the interpolation so you want to move the ogre from one position to another… how long is this going to take? The advantage of keyframe system is that you can specify the position of the ogre in time… but scripting for such system without a tool will be difficult. Still here is a simple suggestion for format:

    (play 'song1.mp3')
(entity 'ogre'
    (position (
        0 (100 100 100)
        2 (100 200 100)
        5 (100 300 100)
        7 (100 300 400)
        8 (100 300 500))
    (mood (
        0 'happy'
        7 'angry'))
    (... more tracks for that entity if you need ...))
(entity 'human'
    (position (.....)))

    Now with format like this you can see at what time where the ogre has to be. So if you have time 1.5 sec in the cutscene you can interpolate between the keyframes with time 0 and 2 sec. Where mood can be something you don’t interpolate just swich when the right tome comes. I think this format is going to be more flexible and will solve your sync issues but I wouldn’t suggest you writing it by hand without tools for big scripts. If your cutscenes are going to be just few sec with a few entities then it may be good for your.

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