我知道这只是早晚的事儿。
UI部分
大佬总是跟我说不要用Canvas，当然是指游戏运行中的某种情况，貌似公司的大佬对于UI的效率很是关心。因为我也不懂太多关于UI的渲染问题所以只能先记下。
上面的视频我看了两遍都没看完，中途都困得不行了…但是确实很重要，一定要整理。
Unity中UI需要了解
摘取上面的视频中的内容
The Absolute Basics
- Canvases generate meshes & draw them
- Drawing happens once per frame
- Generation happens when “something changes”
- “Something changes” = “1 or more UI elements change”
- Change one UI element, dirty the whole canvas
- Yes, one.
What’s a rebuild? Theoretically…
- Three steps:
- Recalculate layouts of auto-layouted elements
- Regenerate meshes for all enabled elements
- Yes, meshed are still created when alpha=0!
- Regenerate materials to help batch meshed
What’s a rebuild? In Reality…
- Usually, all system are dirtied instead of individually
- Notable exceptions:
- Color property
- fill* properties on Image
After all that…
- Canvas takes meshes, divides them into batches
- Sorts the meshes by depth (hierarchy order)
- Yes, this involves a sort() operation!
- AllUI os transparent. No matter what.
- Overdraw is a problem!
The Vicious Cycle
- Sort means performance drops faster-than-linear as number of drawable elements rises.
- Higher number of elements means a higher chance any given element will change.
Slice up your canvases!
- Add more canvases.
- Each canvas owns its own set of UI elements
- Elements on different canvases will not batch.
- Main tool for constraining size of UI batches.
Nesting Canvases
- Canvases can be created within other canvases
- Child canvases inherit rendering settings.
- Maintain own geometry.
- Perform own batching.
后半段我开始听不太懂了……