Assembly Definitions, Explained | Unity Tutorial

This week you can learn about Assembly Definitions, which are a Unity Construct to create C# Projects within your game's "Solution". This allows Unity to determine which scripts needs to be compiled after making a change, instead of naively recompiling the entire project. Compiling fewer scripts lets you get back into the editor faster after making code changes!

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Chapters:
00:00 Topic Introduction
00:52 How Unity works without Assembly Definitions & the use case for them
01:30 How I split up Assembly Definitions
01:59 Examples from the Gun Scriptable Object Series
02:55 Creating an Assembly Definition File & Common Option Overview
04:37 More Advanced Features You'll Probably Never Use
05:10 Why it's Important for Asset Store Packages
05:40 Final Thoughts & Support LlamAcademy

[xx]

I'm just gonna pop it in here, you are such an amazing creator and helped me through so many things with in-depth explanations. Keep the high quality work up!

[ericevanshub]

Very helpful! I'd like to see a part 2 of this with the more advanced assembly def features you find useful, such as multiple folders & symbols. Maybe discussing tests in a separate assembly, etc.

[castlecodersltd]

Thanks for this one. I was starting to get frustrated how long it took to compile, this will really help my project. Thank you ☺

[durvids]

Yes, you!! Thanks for the awesome video!!

[biocronic]

Seems like you have more fun beeing a strange actor than a good tutor or programmer. so many words we dont need. remember if they only make you happy watching this ^^.

[AndresCamiloUrregoRestrepo]

This and the assembly references once saved a project that I had to fix for my job :p

[TharosTheDragon]

The Unity documentation on this is so confusing. I thought you needed to create an assembly definition reference in order for one assembly to reference another assembly. Your video has definitely helped clear things up.

[derbabonennt]

Thank for clearing this topic - always thought it was more complicated❤

[sqdtnz]

In terms of architecture it's quite tricky though, I tried implementing it in an existing (medium sized) project, and there were just quite a few annoying circular references (bad practices in my code), that were hard to solve. Best is to use this right from the start I think.

[davidbone]

great video, just thinking what if you do need circular reference!! what would be the best route ?

[bluzenkk]

can you tell me more about the "Define Constraints" section, i'm still not clear what is it and how to use it. when you say "Unity android has to be define for this to be compiled" what exactly does that mean....if this sentense mean it only compiles when in android, isn't that cover at the Exclude Platform section below where you can check or uncheck the Android?

[polylob]

I'm not sure if this is the right place, but I'm trying to add a symbol preprocessor to my GitHub package, for example, #define MY_PACKAGE. So, I can have pieces of code that can only be compiled if the package is downloaded by using #if MY_PACKAGE. Normally, everything should be grayed out unless I download the package. Is it possible to do something in the assembly of the package to achieve this?

[niallmccaffrey]

as soon as I add an assembly definition, my scripts in that assembly no longer can find namespaces...

[bishoyfahim]

great content but when gun-system part 8 ?

[TechDunk]

I want to use assembly definitions from the start in my latest project, to make sure the project stays reasonably snappy.
I got it working up until I utilized my custom attributes. Here everything works in the inspector, since the attributes reference editor code I have to make another asm def for them only included in the editor.

This works great in editor, but when I start building my project I get errors that the custom attribute namespaces cannot be found. When I enable the asm def for all platforms I get errors that the custom attributes reference editor code, not allowing me to build.

[blitzgrims]

I just found out this channel I want to know how to make a script to make ai flank (shooting game) it would be great to know