Ability to remove unused parts of the Unity emgine to make builds smaller.

Hi,

When I bought Unity 5 I remember that it was advertised that it is in the roadmap the ability to remove unused parts of the engine to make the build, eg apks smaller. Eg if I make a simple 2d game, why pack the 3d engine or the huge 3d physics, lights etch. All these should be packed in pieces only if they are used in the project or at last we can have a choice to take out parts of the engine. I made a small app before some days, very simple with a few graphics and it packed 32mb in android and 64 in ios because of the 64bit code. This is just a waste of space.

 

What are the current strip level choices mean?

 

Beware that this doesn't work with asset bundles - which kind of makes sense since there is no way for Unity to know what you will eventually put into asset bundles. Our project is almost 100% in bundles, so the stripping option will remove things like the particle system.

Personally, I'd prefer a list of features to disable - as I know, for instance, we're never going to use certain features in our project and can safely strip them. Then I'd be able to use this feature to reduce our memory/download bloat.

 

How is that going to work though when the major use of asset bundles is to patch a game with new content without going through the submission of a new client?

 

Also, you should likely default this option to OFF until you figure out what to do about asset bundles - everyone who upgrades a project to a version which has this feature and uses asset bundles will immediately have to debug why their game doesn't work anymore - which is what I did.

 

Ok, let me use our game as an example; we run on iOS/Android/WebGL/etc. Because we run under webGL, we need the initial app size to be as small as possible. Thus, everything except the initial loading screen and error panel is inside an asset bundle. The app itself is just compiled code, two textures, and one UI screen - everything else is dynamically downloaded data. Yes, all the code is there, but it seems like you scan the data, not the code (that, or we're not referencing the ParticleSystem component anywhere in code).

So, the current stripping option strips nearly the entire engine from the game, because our included scene doesn't use most of the engine.

 

So what your saying is that if I build the game and ship it to users with no particle effects the game or bundles, it's going to strip the particle system code. Then I add a particle system into an asset bundle after this build is made and ship it to the user without updating the client, and that code will magically appear in the client executable?

Obviously that can't work without patching the client - which is often not something we can do, or rely on happening when we'd like it to. Whatever solution you end up with should either a) make it very clear that new code is being required when you build new bundle data so that you know you cannot ship them without a client update or b) preferably allow us to mark which subsystems we want to include/strip manually, so we can include them before assets which use them are made.