由于有些手机不支持GrabPass,所以ui上面的毛玻璃不能用这种方式实现
基本思路就这样,实现不麻烦,我直接拿别人写过用grabpass实现的shader,改成用rendertexture
局限性:只能用于背景是场景的
先看效果
Shader "Custom/UIBackBlur"
{
Properties
{
[PerRendererData] _MainTex("Sprite Texture", 2D) = "white" {}
_Color("Main Color", Color) = (1,1,1,1)
_Size("Size", Range(0, 500)) = 1
_BG("BG", 2D) = "white" {}
_Factor("_Factor",Range(0, 1)) = 1
}
Category{
// We must be transparent, so other objects are drawn before this one.
Tags{
"Queue" = "Transparent"
"IgnoreProjector" = "True"
"RenderType" = "Transparent"
"PreviewType" = "Plane"
"CanUseSpriteAtlas" = "True"
}
SubShader{
Pass{
Tags{ "LightMode" = "Always" }
Name "BackBlurHor"
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma fragmentoption ARB_precision_hint_fastest
#include "UnityCG.cginc"
struct appdata_t {
float4 vertex : POSITION;
float2 texcoord : TEXCOORD0;
float4 color : COLOR;
};
struct v2f {
float4 vertex : POSITION;
float4 uvgrab : TEXCOORD0;
float4 color : COLOR;
};
v2f vert(appdata_t v) {
v2f o;
o.vertex = UnityObjectToClipPos(v.vertex);
#if UNITY_UV_STARTS_AT_TOP
float scale = 1.0;
#else
float scale = 1.0;
#endif
o.uvgrab.xy = (float2(o.vertex.x, o.vertex.y*scale) + o.vertex.w) * 0.5;
o.uvgrab.zw = o.vertex.zw;
o.color = v.color;
return o;
}
sampler2D _BG;
float4 _BG_TexelSize;
float4 _MainTex_TexelSize;
float _Size;
uniform float4 _Color;
fixed _Factor;
half4 GrabPixel(v2f i, float weight, float kernelx) {
if (i.uvgrab.x == 0 && i.uvgrab.y == 0) {
kernelx = 0;
}
return tex2Dproj(_BG, UNITY_PROJ_COORD(float4(i.uvgrab.x + _BG_TexelSize.x*kernelx*_Size, i.uvgrab.y, i.uvgrab.z, i.uvgrab.w))) * weight;
}
half4 GrabPixel2(v2f i, float weight, float kernely) {
if (i.uvgrab.x == 0 && i.uvgrab.y == 0) {
kernely = 0;
}
return tex2Dproj(_BG, UNITY_PROJ_COORD(float4(i.uvgrab.x, i.uvgrab.y + _BG_TexelSize.y*kernely*_Size, i.uvgrab.z, i.uvgrab.w))) * weight;
}
half4 frag(v2f i) : COLOR{
half4 sum = half4(0,0,0,0);
sum += GrabPixel(i, 0.05, -4.0);
sum += GrabPixel(i, 0.09, -3.0);
sum += GrabPixel(i, 0.12, -2.0);
sum += GrabPixel(i, 0.15, -1.0);
sum += GrabPixel(i, 0.18, 0.0);
sum += GrabPixel(i, 0.15, +1.0);
sum += GrabPixel(i, 0.12, +2.0);
sum += GrabPixel(i, 0.09, +3.0);
sum += GrabPixel(i, 0.05, +4.0);
half4 sum2 = half4(0, 0, 0, 0);
sum2 += GrabPixel2(i, 0.05, -4.0);
sum2 += GrabPixel2(i, 0.09, -3.0);
sum2 += GrabPixel2(i, 0.12, -2.0);
sum2 += GrabPixel2(i, 0.15, -1.0);
sum2 += GrabPixel2(i, 0.18, 0.0);
sum2 += GrabPixel2(i, 0.15, +1.0);
sum2 += GrabPixel2(i, 0.12, +2.0);
sum2 += GrabPixel2(i, 0.09, +3.0);
sum2 += GrabPixel2(i, 0.05, +4.0);
sum = sum * 0.5 + sum2 * 0.5;
float4 col5 = tex2Dproj(_BG, UNITY_PROJ_COORD(i.uvgrab));
float decayFactor = 1.0f;
if (i.uvgrab.x == 0 && i.uvgrab.y == 0) {
decayFactor = 0;
}
sum = lerp(col5, sum, _Factor) * i.color * _Color;
return sum;
}
ENDCG
}
}
}
}
代码比较简单就是保存的rendertexture赋值给上面shader对应的材质球,然后ui挂这个材质球就ok
为了性能OnPreRender和OnPostRender,而且后面可能还要用后处理
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class CameraTex : MonoBehaviour {
public Material m;
public RenderTexture cameraRenderTex;
public Camera mainCamera;
private int bg = Shader.PropertyToID("_BG");
private void Awake()
{
mainCamera.allowHDR = false;
mainCamera.allowMSAA = false;
}
private void OnPreRender()
{
cameraRenderTex = RenderTexture.GetTemporary(Screen.width, Screen.height, 24, RenderTextureFormat.Default, RenderTextureReadWrite.Default);
mainCamera.targetTexture = cameraRenderTex;
m.SetTexture(bg, cameraRenderTex);
}
private void OnPostRender()
{
mainCamera.targetTexture = null;
Graphics.Blit(cameraRenderTex, null as RenderTexture);
RenderTexture.ReleaseTemporary(cameraRenderTex);
}
}
下面是工程地址
链接:https://pan.baidu.com/s/1ZnlAitgCUEVHTJkS-aIrOw
提取码:3im2