Unity3d:ugui, UI and special effect particle level, bakemesh above 2018.2, particles between two images and in Scrollview

ui The particles shown above generally have two schemes
1. adopt rendertexture Rendering , Can handle hierarchy problems perfectly , But the performance is not good , Multiple cameras
2. Put directly ui Interface adjustment effect sort in layer, But if ui More special effects , The hierarchy is not easy to manage , And more canvas Cause the problem of approval
Now come to the third method, particles BakeMesh（ want 2018.2 Above version ）
come from Github：https://github.com/mob-sakai/ParticleEffectForUGUI
advantage ： Iconicity UGUI You can also adjust the level sorting up and down , Accept Mask Handle

Comparison of various schemes

The particle BakeMesh

principle ： Directly let the particle mesh and map in ui Render in the basic components
Use interface
ParticleSystemRenderer.BakeMesh and ParticleSystemRenderer.BakeTrailsMesh Here is the generation grid information
CanvasRenderer.SetMesh
CanvasRenderer.SetTexture
hold mesh and texture Throw to canvasRenderer Rendering

Code parsing

UIParticle

UIParticle Is the parent of the particle

[RequireComponent(typeof(RectTransform))]
 [RequireComponent(typeof(CanvasRenderer))]
public class UIParticle : MaskableGraphic
{
    
protected override void OnEnable()
        {
    
            UIParticleUpdater.Register(this);

CanvasRenderer Rendering is included in Canvas Medium UI object , It's a Graphic necessary

UIParticleUpdater

Canvas.willRenderCanvases monitor

internal static class UIParticleUpdater
    {
    
        [RuntimeInitializeOnLoadMethod]
        private static void InitializeOnLoad()
        {
    
            Canvas.willRenderCanvases -= Refresh;
            Canvas.willRenderCanvases += Refresh;
        }

Q: Canvas.willRenderCanvases monitor
A: Official explanation ： At the beginning Canvas Events before rendering .
This allows you to defer processing / Update canvas based elements , Until you're about to start rendering them . Here we do the particle generation Mesh, And then by calling particle.canvasRenderer.SetMesh, Rendered particle mesh
Refresh

private static void Refresh(UIParticle particle)
        {
    
            Profiler.BeginSample("[UIParticle] Bake mesh");
            BakeMesh(particle);
            Profiler.EndSample();

           Profiler.BeginSample("[UIParticle] Set mesh to CanvasRenderer");
            particle.canvasRenderer.SetMesh(particle.bakedMesh);
            Profiler.EndSample();
        }