Bloom前

Bloom后

代码

using UnityEngine;

public class Bloom : PostEffectsBase
{

    public Shader bloomShader;
    private Material bloomMaterial = null;
    public Material material
    {
        get
        {
            bloomMaterial = CheckShaderAndCreateMaterial(bloomShader, bloomMaterial);
            return bloomMaterial;
        }
    }

    // Blur iterations - larger number means more blur.
    [Range(0, 4)]
    public int iterations = 3;

    // Blur spread for each iteration - larger value means more blur
    [Range(0.2f, 3.0f)]
    public float blurSpread = 0.6f;

    [Range(1, 8)]
    public int downSample = 2;

    [Range(0.0f, 4.0f)]
    public float luminanceThreshold = 0.6f;

    void OnRenderImage(RenderTexture src, RenderTexture dest)
    {
        if (material != null)
        {
            material.SetFloat("_LuminanceThreshold", luminanceThreshold);

            int rtW = src.width / downSample;
            int rtH = src.height / downSample;

            RenderTexture buffer0 = RenderTexture.GetTemporary(rtW, rtH, 0);
            buffer0.filterMode = FilterMode.Bilinear;

            Graphics.Blit(src, buffer0, material, 0);

            for (int i = 0; i < iterations; i++)
            {
                material.SetFloat("_BlurSize", 1.0f + i * blurSpread);

                RenderTexture buffer1 = RenderTexture.GetTemporary(rtW, rtH, 0);

                // Render the vertical pass
                Graphics.Blit(buffer0, buffer1, material, 1);

                RenderTexture.ReleaseTemporary(buffer0);
                buffer0 = buffer1;
                buffer1 = RenderTexture.GetTemporary(rtW, rtH, 0);

                // Render the horizontal pass
                Graphics.Blit(buffer0, buffer1, material, 2);

                RenderTexture.ReleaseTemporary(buffer0);
                buffer0 = buffer1;
            }

            material.SetTexture("_Bloom", buffer0);
            Graphics.Blit(src, dest, material, 3);

            RenderTexture.ReleaseTemporary(buffer0);
        }
        else
        {
            Graphics.Blit(src, dest);
        }
    }
}

shader

Shader "Hidden/Bloom"
{
    Properties
    {
        _MainTex("Base (RGB)", 2D) = "white" {}
        _Bloom("Bloom (RGB)", 2D) = "black" {}
        _LuminanceThreshold("Luminance Threshold", Float) = 0.5
        _BlurSize("Blur Size", Float) = 1.0
    }
        SubShader
        {
            CGINCLUDE

            #include "UnityCG.cginc"

            sampler2D _MainTex;
            half4 _MainTex_TexelSize;
            sampler2D _Bloom;
            float _LuminanceThreshold;
            float _BlurSize;

            struct v2f
            {
                float4 pos : SV_POSITION;
                half2 uv : TEXCOORD0;
            };

            v2f vertExtractBright(appdata_img v)
            {
                v2f o;

                o.pos = UnityObjectToClipPos(v.vertex);

                o.uv = v.texcoord;

                return o;
            }

            fixed luminance(fixed4 color)
            {
                return  0.2125 * color.r + 0.7154 * color.g + 0.0721 * color.b;
            }

            fixed4 fragExtractBright(v2f i) : SV_Target
            {
                fixed4 c = tex2D(_MainTex, i.uv);
                fixed val = clamp(luminance(c) - _LuminanceThreshold, 0.0, 1.0);

                return c * val;
            }

            struct v2fBloom
            {
                float4 pos : SV_POSITION;
                half4 uv : TEXCOORD0;
            };

            v2fBloom vertBloom(appdata_img v)
            {
                v2fBloom o;

                o.pos = UnityObjectToClipPos(v.vertex);
                o.uv.xy = v.texcoord;
                o.uv.zw = v.texcoord;

                #if UNITY_UV_STARTS_AT_TOP			
                if (_MainTex_TexelSize.y < 0.0)
                    o.uv.w = 1.0 - o.uv.w;
                #endif

                return o;
            }

            fixed4 fragBloom(v2fBloom i) : SV_Target
            {
                return tex2D(_MainTex, i.uv.xy) + tex2D(_Bloom, i.uv.zw);
            }

            ENDCG

            ZTest Always Cull Off ZWrite Off

            Pass
            {
                CGPROGRAM
                #pragma vertex vertExtractBright  
                #pragma fragment fragExtractBright  

                ENDCG
            }

            UsePass "MyShader/GaussianBlur/GAUSSIAN_BLUR_VERTICAL"

            UsePass "MyShader/GaussianBlur/GAUSSIAN_BLUR_HORIZONTAL"

            Pass
            {
                CGPROGRAM
                #pragma vertex vertBloom  
                #pragma fragment fragBloom  

                ENDCG
            }
        }
            FallBack Off
}

参考 我买的 unity shader 入门精要