//预览图
//原理
一个摄像机CullingMask设置只可见"Distortion"的Layer（需要自己手动加），输入到一张RenderTexture，其实就是用于确定哪里要扭曲。
另外一个摄像机CullingMask设置成对除了"Distortion"的Layer可见，并挂上后期效果脚本。
//Shader代码
Shader "Hidden/Distortion"
{
Properties
{
_MainTex ("Texture", 2D) = "white" {}
_Noise ("Noise", 2D) = "black" {}
_DistortionMask ("Distortion Mask", 2D) = "black" {}
_DistortionStrength ("Distortion Strength", Float) = 0.1
_DistortTimeFactor ("_Distort Time Factor", Float) = 0.1
}
SubShader
{
// No culling or depth
Cull Off ZWrite Off ZTest Always Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag #include "UnityCG.cginc" struct appdata
{
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
}; struct v2f
{
float2 uv : TEXCOORD0;
float4 vertex : SV_POSITION;
}; v2f vert (appdata v)
{
v2f o;
o.vertex = mul(UNITY_MATRIX_MVP, v.vertex);
o.uv = v.uv;
return o;
} sampler2D _MainTex; sampler2D _DistortionMask;
sampler2D _Noise;
float _DistortionStrength;
float _DistortTimeFactor; fixed4 frag (v2f i) : SV_Target
{
//wave strength
fixed strength = tex2D(_DistortionMask, i.uv).r; //noise
fixed2 noi = tex2D(_Noise, i.uv-fixed2(,_Time.y * _DistortTimeFactor)); //uv offset
fixed2 uvOffset = strength*noi.xy*_DistortionStrength; fixed4 col = tex2D(_MainTex, i.uv.xy+uvOffset.xy); return col;
}
ENDCG
}
}
}
//C#代码
using UnityEngine;
using System.Collections; [ExecuteInEditMode]
public class DistortionPostEffect : MonoBehaviour
{
private Camera distortionCam;
public Material DistortionMat;
private RenderTexture rt;
void Awake()
{
Transform go = transform.Find("Distortion");
if (null == go) {
go = (new GameObject ("Distortion")).transform;
}
go.transform.parent = transform;
go.transform.localPosition = Vector3.zero;
go.transform.rotation = Quaternion.identity; distortionCam = go.GetComponent<Camera> ();
if (null == distortionCam) {
distortionCam = go.gameObject.AddComponent<Camera> ();
}
distortionCam.clearFlags = CameraClearFlags.Color;
distortionCam.backgroundColor = Color.black;
//rt = RenderTexture.GetTemporary (Screen.width / 2, Screen.height / 2);
rt = RenderTexture.GetTemporary ( , );
rt.wrapMode = TextureWrapMode.Repeat;
distortionCam.targetTexture = rt;
distortionCam.cullingMask = LayerMask.GetMask ("Distortion"); gameObject.GetComponent<Camera> ().cullingMask &= (~distortionCam.cullingMask);
}
// Use this for initialization
void Start () { } // Update is called once per frame
void Update () { } void OnRenderImage(RenderTexture src,RenderTexture dest)
{
DistortionMat.SetTexture ("_DistortionMask", rt);
Graphics.Blit (src, dest, DistortionMat);
} }