1.
Unity: Best Practices
how to save memory and the world

2.
Point of this meeting
We don’t want to see this
That’s pretty much it
This bullet point is pure decoration

3.
Using ForEach Loops
Don’t use them in code that you allow Unity to compile for
you
Use it to iterate other generic collection (List<T>) with a
recent compiler.

4.
Closures and LINQ
This code cause minor leak =>
Closure: this is worse =>
Not an expert in LINQ but I avoid using it during runtime

5.
Coroutines
Coroutines are useful, we can use it.
Need to avoid calling StartCoroutine() often on frame-
based

6.
Strings
Don’t use them… Just kidding, you can
Runtime, System.Text.StringBuilder >> String.concat().
if(string == string2) << use string.Equals(string2)
faster especially for short strings

7.
Basic Physx
Do not use mesh collider
Do not move a static collider (can be traced in profiler)
There’s A LOT MORE but just covering the basics here

8.
Basic Graphx (CPU)
Target ~100 draw calls on mobile
Using call batching to reduce meshes number
Using atlas texture and fewer materials

9.
Basic Graphx 1-Fillrate (Mobile GPU)
It’s all about shading for fillrate
Alpha blended not alpha testing
Pick lowest number precision format (half, float)
Avoid expensive math (pow, exp, log…)

10.
Basic Graphx 2-Bandwith (Mobile GPU)
Texture compression / 16-bit
Using mipmaps or render size checking
Vertex count below 200/300K / not to much overdraw alpha
SET STATIC ON NON-MOVING OBJECT FOR BATCH !!!

11.
Tips and Tricks
Calling onBecameVisible / onBecameInvisible to stop
calling scripts when not rendered
Using time-based coroutine instead of update()
- Do something every second instead of every frame
Struct instead of Class for local Data

12.
Using the tool
Network Emu: Useful to test low-bandwidth
Unit Tests Editor: Planning test easy
VS Debug: Breakpoints, Watch, step by step…
Remote profiling for android/iOS

13.
Going further
Object Pools, signals, nullable types…
GetRuntimeMemorySize(Object) to track memory leaks
Useful resources :
Optim from ARM CTO
Patterns and code
SIGGRAPH 2011 Optim Unity Paper

14.
Improving quality
Audio, Particles, Lights, image-effects…
Procedural content instead of a bunch of assets
A 3D world around a 2D game