Unity NGUI UIPanel for particle clipping

Ext.: http://www.cnblogs.com/jietian331/p/5075487.html

When using unity for game development, it is sometimes necessary to use particles under scroll view, but particles are not clipped by uipanel, and I provide script particlesystemclipper to handle this situation. The idea is that the finalclipregion of the UIPanel is converted into a region in the unity3d world coordinate system and then passed to the shader of the particle to be cropped. The code is as follows:

usingSystem;usingUnityengine; [Requirecomponent (typeof(UIPanel))] Public classparticlesystemclipper:monobehaviour{Const stringShadername ="bleach/particles Additive Area Clip"; Const floatClipinterval =0.5f;    UIPanel M_targetpanel;    Shader M_shader; voidStart () {//Find PanelM_targetpanel = getcomponent<uipanel>(); if(M_targetpanel = =NULL)            Throw NewArgumentNullException ("Cann ' t find the right UIPanel"); if(M_targetpanel.clipping! =UIDrawCall.Clipping.SoftClip)Throw NewInvalidOperationException ("Don ' t need to clip"); M_shader=Shader.find (shadername); if(! Isinvoking ("Clip")) invokerepeating ("Clip",0, Clipinterval); } Vector4 Calccliparea () {varClipregion =m_targetpanel.finalclipregion; Vector4 Nguiarea=NewVector4 () {x= CLIPREGION.X-CLIPREGION.Z/2, y= CLIPREGION.Y-CLIPREGION.W/2, Z= clipregion.x + clipregion.z/2, W= CLIPREGION.Y + CLIPREGION.W/2        }; varUiroot = luautils.uiroot.getcomponent<uiroot>(); varpos = m_targetPanel.transform.position-uiRoot.transform.position; floath =2; floattemp = h/Uiroot.manualheight; return NewVector4 () {x= pos.x + nguiarea.x *temp, y= Pos.y + nguiarea.y *temp, Z= pos.x + nguiarea.z *Temp, W= Pos.y + NGUIAREA.W *temp}; }    voidClip () {Vector4 Cliparea=Calccliparea (); varParticlesystems = This. Getcomponentsinchildren<particlesystem>();  for(inti =0; i < particlesystems.length; i++)        {            varPS =Particlesystems[i]; varMat =ps.renderer.material; if(Mat.shader.name! =shadername) Mat.shader=M_shader; Mat. Setvector ("_area", Cliparea); }    }    voidOnDestroy () {Cancelinvoke ("Clip"); }}

The corresponding shader code is as follows:

Shader"bleach/particles Additive Area Clip"{Properties {_tintcolor ("Tint Color", Color) = (0.5,0.5,0.5,0.5) _maintex ("particle Texture", 2D) =" White"{} _area (" Area", Vector) = (0,0,1,1)} Category {Tags {"Queue"="Transparent" "Ignoreprojector"="True" "Rendertype"="Transparent"} Blend srcalpha one alphatest Greater. oncolormask RGB cull off Lighting off Zwrite off Fog {Color (0,0,0,0)} subshader {Pass {cgprogram#pragmaVertex vert#pragmaFragment Frag#pragmaMulti_compile_particles#include"Unitycg.cginc"sampler2d _maintex;                Fixed4 _tintcolor;                                FLOAT4 _area; structappdata_t {float4 vertex:position;                    Fixed4 Color:color;                FLOAT2 texcoord:texcoord0;                }; structv2f {float4 vertex:sv_position;                    Fixed4 Color:color;                    FLOAT2 texcoord:texcoord0;                FLOAT2 Worldpos:texcoord1;                                };                FLOAT4 _maintex_st;                    v2f Vert (appdata_t v) {v2f o; O.vertex=Mul (UNITY_MATRIX_MVP, V.vertex); O.texcoord=Transform_tex (V.texcoord,_maintex); O.color=V.color; O.worldpos=Mul (_object2world, V.vertex). XY; returno; } fixed4 Frag (v2f i): sv_target {BOOLInarea = i.worldpos.x >= _area.x && i.worldpos.x <= _area.z && i.worldpos.y >= _area.y && I.worldpos.y <=_AREA.W; returnInarea?2.0f* I.color * _tintcolor * tex2d (_maintex, I.texcoord): Fixed4 (0,0,0,0); } ENDCG} }}

Unity NGUI UIPanel for particle clipping