1 local RenderTexture = CS.UnityEngine.RenderTexture 2 local Rect =CS.UnityEngine.Rect 3 local Screen =CS.UnityEngine.Screen 4 local Texture2D = CS.UnityEngine.Texture2D 5 local TextureFormat = CS.UnityEngine.TextureFormat 6 local GaussianBlurBg = {} 7 8 --主要思路：从屏幕读取像素 保存在texture2d中 9 --核心API：texture2d:ReadPixels(renderWidth, renderHeight, TextureFormat.RGB24, false, true) 10 11 ---输出图片 12 GaussianBlurBg.ExportTexture = function() 13 local cameraArr = GaussianBlurBg.GetCurrCamera() 14 local renderWidth,renderHeight = GaussianBlurBg.DrawingSize() 15 return GaussianBlurBg.ScreenCapture(cameraArr,renderWidth,renderHeight) 16 end 17 18 --获取相机组 19 GaussianBlurBg.GetCurrCamera = function() 20 local cameraArr = {} 21 local UIMgrIns = UIManager:Instance() 22 table.insert(cameraArr, UIMgrIns.UICamera) 23 table.insert(cameraArr, UIMgrIns.MainCamera) 24 return cameraArr 25 end 26 27 --算出渲染大小 28 GaussianBlurBg.DrawingSize = function() 29 --高宽比 30 local proportion = (Screen.height * 1.0 / Screen.width) 31 --乘以0.1 是为了更小 32 local renderWidth = math.min(100,math.ceil(Screen.width * 0.1)) 33 --乘以高宽比是为了与原比例一致 34 local renderHeight = math.ceil(renderWidth * proportion) 35 return renderWidth,renderHeight 36 end 37 38 --屏幕读取像素渲染到一张图片上 39 GaussianBlurBg.ScreenCapture = function(cameraArr,renderWidth,renderHeight) 40 if cameraArr == nil or #cameraArr == nil then return nil end 41 local camerList,cameraMap,oldTargetTexture = {},{},{} 42 for _, v in pairs(cameraArr) do 43 if not IsNull(v) and cameraMap[v] == nil then 44 cameraMap[v] = v 45 table.insert(camerList, v) 46 end 47 end 48 if #camerList <= 0 then return nil end 49 if type(renderWidth) ~= "number" or renderWidth <= 0 then renderWidth = 100 end 50 if type(renderHeight) ~= "number" or renderHeight <= 0 then renderHeight = 100 end 51 local renderTex = RenderTexture.GetTemporary(renderWidth, renderHeight, 0) 52 --缓存原先的渲染相机及渲染目标 53 for _, came in pairs(camerList) do 54 if not IsNull(came) and came.gameObject.activeSelf then 55 table.insert(oldTargetTexture, { came = came, targetTexture = came.targetTexture }) 56 came.targetTexture = renderTex 57 came:Render() 58 end 59 end 60 RenderTexture.active = renderTex 61 local _tex = Texture2D(renderWidth, renderHeight, TextureFormat.RGB24, false, true) 62 _tex:ReadPixels(Rect(0, 0, renderWidth, renderHeight), 0, 0) 63 _tex:Apply(false, false) 64 --要还原 否则丢失渲染目标 65 for _, v in pairs(oldTargetTexture) do 66 if not IsNull(v.came) then 67 v.came.targetTexture = v.targetTexture 68 end 69 end 70 RenderTexture.active = nil 71 RenderTexture.ReleaseTemporary(renderTex) 72 return _tex 73 end 74 75 exports.GaussianBlurBg = GaussianBlurBg 76 return GaussianBlurBg
模糊 shader
1 Shader "Effect/ImageBlur" 2 { 3 Properties 4 { 5 _MainTex("Texture", 2D) = "white" {} 6 //ugui mask 7 [HideInInspector]_StencilComp("Stencil Comparison", Float) = 8 8 [HideInInspector]_Stencil("Stencil ID", Float) = 0 9 [HideInInspector]_StencilOp("Stencil Operation", Float) = 0 10 [HideInInspector]_StencilWriteMask("Stencil Write Mask", Float) = 255 11 [HideInInspector]_StencilReadMask("Stencil Read Mask", Float) = 255 12 [HideInInspector]_ColorMask("Color Mask", Float) = 15 13 //================================================================================ 14 _BlurSize("Blur Size", Float) = 2 15 _Brightness("Brightness", Float) = 1 //调整亮度 16 _Saturation("Saturation", Float) = 1 //调整饱和度 17 _Contrast("Contrast", Float) = 1 //调整对比度 18 } 19 20 CGINCLUDE 21 22 #include "UnityCG.cginc" 23 24 sampler2D _MainTex; 25 uniform half4 _MainTex_TexelSize; 26 uniform float _BlurSize; 27 half _Brightness; 28 half _Saturation; 29 half _Contrast; 30 31 static const half weight[4] = { 0.0205, 0.0855, 0.232, 0.324 }; 32 static const half4 coordOffset = half4(1.0h, 1.0h, -1.0h, -1.0h); 33 34 struct appdata_t 35 { 36 float4 vertex : POSITION; 37 float4 color : COLOR; 38 float2 texcoord : TEXCOORD0; 39 }; 40 41 struct v2f_blurSGX 42 { 43 float4 pos:SV_POSITION; 44 half2 uv:TEXCOORD0; 45 float4 color : COLOR; 46 half4 blurFactor:TEXCOORD1; 47 }; 48 49 v2f_blurSGX vert_BlurHorizontal(appdata_t v) 50 { 51 v2f_blurSGX o; 52 o.pos = UnityObjectToClipPos(v.vertex); 53 o.uv = v.texcoord.xy; 54 o.blurFactor.xy = _MainTex_TexelSize.xy * 2 * _BlurSize; 55 o.color = v.color; 56 return o; 57 } 58 59 60 fixed4 Tex2DBlurring(sampler2D tex, half2 texcood, half2 blur) 61 { 62 //快速模糊 63 //const int KERNEL_SIZE = 3; 64 //const float KERNEL_[3] = { 0.4566, 1.0, 0.4566 }; 65 66 //中等模糊 67 //const int KERNEL_SIZE = 5; 68 //const float KERNEL_[5] = { 0.2486, 0.7046, 1.0, 0.7046, 0.2486 }; 69 70 //高级模糊 71 const int KERNEL_SIZE = 7; 72 const float KERNEL_[7] = { 0.1719, 0.4566, 0.8204, 1.0, 0.8204, 0.4566, 0.1719 }; 73 float4 o = 0; 74 float sum = 0; 75 float2 shift = 0; 76 for (int x = 0; x < KERNEL_SIZE; x++) 77 { 78 shift.x = blur.x * (float(x) - KERNEL_SIZE / 2); 79 for (int y = 0; y < KERNEL_SIZE; y++) 80 { 81 shift.y = blur.y * (float(y) - KERNEL_SIZE / 2); 82 float2 uv = texcood + shift; 83 float weight = KERNEL_[x] * KERNEL_[y]; 84 sum += weight; 85 uv.x = clamp(uv.x, 0.02, 0.98); 86 uv.y = clamp(uv.y, 0.02, 0.98); 87 o += tex2D(tex, uv) * weight; 88 } 89 } 90 fixed4 renderTex = (o / sum); 91 //brigtness亮度直接乘以一个系数，也就是RGB整体缩放，调整亮度 92 fixed3 finalColor = renderTex * _Brightness; 93 //saturation饱和度：首先根据公式计算同等亮度情况下饱和度最低的值： 94 fixed gray = 0.2125 * renderTex.r + 0.7154 * renderTex.g + 0.0721 * renderTex.b; 95 fixed3 grayColor = fixed3(gray, gray, gray); 96 //根据Saturation在饱和度最低的图像和原图之间差值 97 finalColor = lerp(grayColor, finalColor, _Saturation); 98 //contrast对比度：首先计算对比度最低的值 99 fixed3 avgColor = fixed3(0.5, 0.5, 0.5); 100 //根据Contrast在对比度最低的图像和原图之间差值 101 finalColor = lerp(avgColor, finalColor, _Contrast); 102 //返回结果，alpha通道不变 103 return fixed4(finalColor, renderTex.a); 104 } 105 106 fixed4 frag_Blur(v2f_blurSGX i) :SV_Target 107 { 108 fixed4 color = Tex2DBlurring(_MainTex,i.uv,i.blurFactor.xy); 109 color.a = i.color.a; 110 return color; 111 } 112 113 114 ENDCG 115 116 SubShader 117 { 118 //ugui mask No culling or depth 119 Cull Off ZWrite Off 120 Stencil 121 { 122 Ref[_Stencil] 123 Comp[_StencilComp] 124 Pass[_StencilOp] 125 ReadMask[_StencilReadMask] 126 WriteMask[_StencilWriteMask] 127 } 128 129 Fog{ Mode Off } 130 Blend SrcAlpha OneMinusSrcAlpha 131 ColorMask[_ColorMask] 132 133 Pass 134 { 135 CGPROGRAM 136 #pragma vertex vert_BlurHorizontal 137 #pragma fragment frag_Blur 138 ENDCG 139 } 140 } 141 }
用法：
1.创建一个材质球 ，把 ImageBlur.shader 挂上
2.加一个Raw Image 组件，GaussianBlurBg.ExportTexture 获取的值 赋值给 Raw Image的 tetxure 属性
效果：
总结知识点：
1.CS.UnityEngine.RenderTexture.GetTemporary：系统api 获取临时渲染纹理
public static RenderTexture GetTemporary(int width, int height, int depthBuffer);
参数width、height 不能小于等于0
2.Camera.targetTexture 给摄像机设置渲染图片
3.Camera:Render() 手动渲染摄像机
4.Texture2D
5.Texture2D:ReadPixels // ReadPixels 从屏幕读取像素保存到纹理数据中
6.Texture2D:Apply() 对上述更改的应用
public void Apply([DefaultValue("true")] bool updateMipmaps, [DefaultValue("false")] bool makeNoLongerReadable);
7.Rendertexture的分配和销毁上有一个地方需要注意：
如果频繁的要new一个rt出来，不要直接new，而是使用RenderTexture提供的GetTemporary和ReleaseTemporary，
它将在内部维护一个池，反复重用一些大小格式一样的rt资源，因为让GPU为你分配一个新的texture其实是要耗时间的。