Creating multiple scenes for a project using Sequences package

[akent99]

One thing I am not understanding is how to have multiple scenes in a project when using the Sequences package. I noticed you can right click on a sequence in the Sequences window / Structure panel, and it does create a new Scene file (I have to select where to save it and specify the name). However it is empty - no game objects.

I can add game objects myself, but I was expecting to see game objects added and all connected together for me, like in the first scene I had.

I note that the Structure panel does list the new scene I created under the Load menu. So it thinks it did something.

I am also trying to understand when to create a new Scene. E.g. is lighting data per scene, meaning I have to start a new scene file if the Lighting window details need to change? (Sorry, still learning Unity.)

I also tried creating my own new empty scene, but it did not add all the game objects into that either. Is the idea you only ever have one scene per project? (That does not feel right.)

Thanks!

Version: Sequences 1.0.0-pre.6 in Unity 2020.3.9f1

[ellka]

Hi! Before I dive into trying to answer your question, can you clarify for me what is your expectation when creating a Scene via the context menu of a sequence in the Sequences window/Structure panel?

[akent99]

From a requirements point of view, there are multiple aspects going through my mind:

• My sets are sometimes large - e.g. a full city, a detailed school with complete classrooms and equipment, etc. I worry about performance of a scene having these all loaded at the same time.
• Scope of damage - things crash and go wrong at times. Separate scenes “feels safer” so I can limit the impact of damage if I do something wrong or there is a crash etc.
• Scope of scene settings - I am still learning Unity. I don’t understand yet what is “scene scoped” beyond game objects. For example, how does baked lighting work? I thought it was related to a scene (baking lighting for the objects in the current scene). No idea how that works if I have multiple sets in sequences - what does baking use? How much can I do with scripts to change settings when flipping between sequence sets vs when should I create a new scene.
• Organizational complexity - smaller scenes can keep a project easier to understand.

What did I expect? My project is to create a series of short episodes. I don’t mind one scene per episode as a mental model. But a full movie in a single scene? The render time starts to become a concern. I would rather put each “beat” into its own scene and render them separately. (A beat is often around 5 mins long in a movie.) Then glue the clips together using Adobe Premiere Pro or similar. It helps me control the workflow of building up a full movie.

I started with trying to create a new empty scene then add things to it - but I could not work out how to. It was only by chance that I noticed the right click and “create scene”. I assumed it would let me decide what granularity of sequence to put into scenes, maybe allowing me to more efficiently open small scenes during editing, only having to load up a full episode for the final render (maybe). I kind of assumed because prefabs were being used everywhere, things can be shared between scenes effectively.

But what I was really trying to work out is the above bullet points - how that aligns with the approach you have built, on the assumption you have solved them already (e.g. thought about what is scoped per scene - don’t let me share sequences between scenes if it is dangerous because the scene settings might be different). My expectation was if you allowed me to create a scene for a nested sequence then it must be safe to do. If I can only do it on master sequences, that would tell me it is not safe to do (and I might create a new master sequence per act in an episode instead of per complete episode. But what scares me is putting a “large” project into a single scene (performance, risk of damage, organizational complexity, etc). I don’t want to start a new project each time.

I hope that helps!

[ellka]

That helps a lot! Thanks for taking the time to details all that, it is definitely precious feedback for us!

So, if I understand correctly, when using the “Create Scene” on a sequence you expect to see this sequence being isolated in a different scene that you can then populate with things proper to this sequence. Is that right?

The “Create Scene” action allows you to create new scenes that will be “associated” with a sequence, but it won’t isolate the sequence in it.

A generic rule about Unity is that cross-scene reference are not natively supported. So the whole cinematic structure (i.e. the hierarchy of “sequence” game objects) must be in the same scene. And every things that are animated in one of the sequence timeline must be in the same scene as well.

However, what we introduced, is the ability to control scene activation (and deactivation) through Timeline. This is what the “Create Scene” action will do for you. It will create a new empty Unity scene and a new track (and clip) in the selected sequence timeline (you can see what this track looks like in the screenshot bellow).

Additional scenes like that can be used to contains environment/set for example (which I think would, at least partially, answer some of your needs).

Just note that this track controls the activation state of a Scene, not its loading state. So to be able to activate or deactivate a Scene, it must be previously loaded in the Hierarchy (this is what the other “Load Scenes” and “Load Specific Scene” menu items are used for).

I can’t give you more answer on the technicality around lighting and stuff myself as I don’t know this area enough. I can at least confirm that it requires a Scene to bake light, but I can’t speak about multi scene/baking combination (we may be able to find someone to help on this bit if needed or redirect you to appropriate documentations).

I hope it helps to clarify the feature!
And I acknowledge that it was not your prior expectation for it. Regarding that, does, what I described, seems to cover your need? And if not, what would you like to be able to do more (or different)?

[akent99]

… okay … so it’s more like “Create Scene Activation”…?

Regarding does it cover my needs… I kinda understand what you are saying, but to be honest I don’t know. I don’t know enough about Unity to understand if it will reduce scene complexity, avoid having to load all (large) sets into memory at once, or whether I need different sets if there is any scoping per set that I should be considering (like baking lights). So I don’t understand it well enough to answer the question.

At the moment it feels like the new Sequences support requires me to put all master sequences (and all subsequences) in the one scene. I assume there is no sharing between master timelines, so it “feels” like there is not technical reason they need to be in the one scene (?).

If Scenes are being used to allow sets or similar to be unloaded to avoid everything in memory at once, how does that work with “Sets” in asset collections? It feels like you have created this logical model (“sets”) and then already bailed on it for scenes… - that is I have to understand Sets and Scenes to understand the structure of a project.

One scene for everything worries me (as in previous post, due to size), but I don’t have the experience to truly know if a problem or not. For example, you don’t design a game to have every location loaded at once. You can limit resource usage via scenes to have only one part loaded at a time. But the sequences support “feels like” you have to load it all at once? That feels wrong - but I would ask Unity experts that question, not me!

Disclaimer: not fully understanding means some of the above is probably completely off the mark!

[akent99]

My reading of Unity - Manual: Lighting Data Asset sounds like lighting data is stored for a scene. So it would be good to understand how Sequences changing Sets based on the current selection will work with scene lighting data.

Also, after trying things for a while, I basically got it into a state where my existing sequences under a master sequence got disconnected from the Structure panel (they show up in red now, as if I had done a rename). I have been trying so many things I don’t know which step broke it. But I am now not sure how to recover a scene with all the sequences in it.

It also required me to open up scenes one by one until I found the right one that had my first master sequence in it. (I had to remember the right one, unlike the nested scenes where you could load and open them using right click in the Structure panel).

The other master sequences I tried to create with other scenes open are now lost (not connected to any scene I can find). It might be useful (or at least make me feel safer) if I can reconstruct a scene sequence objects from the contents of the Structure panel (assuming Structure remembers enough to do so).

[ellka]

So, just to clarify some bits:

• Different Master Sequence can be in different scenes. But one Master Sequence with all its sequences must live in the same scene (just because of the “cross scene reference” limitation).
• Using extra scene for set and lighting is one possibility. Having your sets as Sequence Asset (Prefab basically) is another option. You could also have parts of a set in a Scene and other part via Sequence Asset… this really depends on the need. For baking lighting though, as you said, you need a Scene, so option one would be the one to go in this case. All that are really depending on needs and/or liking.
• In the Project view, under the Sequences folder, you have one folder for every Sequence structures you created. In each of this folder you have a specific MasterSequence asset that you can drag & drop in any Scene to recreate the GameObject structure. It won’t re-instantiate every Sequence Asset /Game Objects that could have been previously added to the structure though, is this a limitation for you?

For the rest of your feedback, I understand that you would like a way to re-open a Master Sequence Scene without having to search it in the Project view by hand, is that right?

About the “Missing GameObject” bug, I’m really sorry to hear it is that annoying. You can try to simply close and re-open the Sequences window until we release a proper fix for it. I just tried it on my side, it should do the trick as it’s really just a UI refresh problem.

Otherwise, I know I already said that a lot, but your feedback is really valuable! There are a bunch of stuff that we guessed we would/could need, but it’s hard to tell what is really important without proper user feedback. So, thank you for all your time spend testing and writing those feedback to us!

[akent99]

Thanks for the explanations - I think I am understanding it now (and got a fair bit of it to work, as per other thread). I plan to proceed using Scene Activation as that would seem to allow me to share a scene (with baking etc) more easily.

Feedback: Creating a new scene was trivial. Loading an existing scene took a little head scratching (I ended up adding a Scene Activation Track, adding an activation clip, then in the Inspector panel selecting the scene from there - doable, just took me a bit to work out the steps.) You might consider a “Add Scene” alongside “Create Scene” in the right button menu to make it a bit easier if possible.

“It won’t re-instantiate every Sequence Asset /Game Objects that could have been previously added to the structure though, is this a limitation for you?” - I think it is fine. It was more a matter of understanding ways of making it work. I now have two approaches: scene activation and creating a new master sequence per location (and adding the set to the master sequence). Once this was clear, I don’t think I need to add the master sequence to a new scene any more thanks.

“I understand that you would like a way to re-open a Master Sequence Scene without having to search it in the Project view by hand, is that right?” Yes, that would be convenient. I forgot the scene name I used once, and I had to reopen each scene one by one until I found the right one again. (In a real project I would be more disciplined over scene names to align them with master sequence names, so while convenient it is not mandatory.)

“Missing GameObject bug” - cool, will try reloading when I come across it.

Your welcome to the feedback if helpful. Its just one voice, and I am still working through it all, but I can see a path forward now that makes sense - so thank your for the time explaining it too! I am revising this blog post as I learn more.

If you want ideas for the future, because I am planning to use animation clips, what would be nice is a way to make them easier to manage (in addition to giving me the option somehow to make a character use a timeline per sequence asset prefab variant OR an animation track for the character). In particular, I have “global” clips for characters (e.g. “sit on chair”), clips for a specific character (e.g. a stylized walk for a specific character), and clips for a specific sequence (recorded via mocap capture). I use avatar masks and override tracks to combine them - so its a little complex. Somehow associating animation clips with characters in the Structure panel could be nice… (but I have not thought it through completely).

Related, I am using EVMC4U at the moment which requires me to do some manual steps to manage animation recordings. E.g. I have to move the clips around myself into the right directory. Might be relevant to your facial virtual camera support too. (Is it really called “virtual camera”, just like Cinemachine virtual cameras? Confusing!)