Unity shader实现自由放大缩小效果

本文实例为大家分享了Unity shader实现自由放大缩小效果的具体代码，供大家参考，具体内容如下

代码：

以下实现的shader代码：

Shader "Hidden/Wave"
{
Properties
{
_MainTex ("Texture", 2D) = "white" {}
_WaveWidth("Wave Width",float) = 0.5
_CenterX("CenterX",float)=0.5
_CenterY("CenterY",float)=0.5
}
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;
 };

float _WaveWidth;
 float _CenterX;
 float _CenterY;
 v2f vert (appdata v)
 {
 v2f o;
 o.vertex = UnityObjectToClipPos(v.vertex);
 o.uv = v.uv;
 return o;
 }

sampler2D _MainTex;

fixed4 frag (v2f i) : SV_Target
 {
 float2 center=float2(_CenterX,_CenterY);
 float2 distance= center - i.uv;
 float x=center.x+ center.x*(-distance.x/center.x) *(1-_WaveWidth);
 float y=center.y+ center.y*(-distance.y/center.y) *(1-_WaveWidth);
 float2 uv = float2(x,y);
 return tex2D(_MainTex, uv);  
 }
 ENDCG
}
}
}

主要的内容还是在frag中。

下面是挂在摄像机上的脚本：

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class WaveCreame : MonoBehaviour {

public Shader waveShader = null;
 [Range(0.0f,1f)]
 public float waveWidth = 0.3f;
 private Material m_WaveMaterial = null;
 private float m_CenterX = 0.5f;
 private float m_CtenterY = 0.5f;
// Use this for initialization
void Start () {
   m_WaveMaterial = new Material(waveShader);
}

// Update is called once per frame
void Update () {
   Vector3 pos = Input.mousePosition;
   m_CenterX = pos.x / Screen.width;
   m_CtenterY = pos.y / Screen.height;
   if (Input.GetMouseButton(0)) {
     waveWidth += Time.deltaTime * 0.5f;
   }
   if (Input.GetMouseButton(1))
   {
     waveWidth -= Time.deltaTime * 0.5f;
   }
 }

private void OnRenderImage(RenderTexture source, RenderTexture destination)
 {
   if (waveShader == null || m_WaveMaterial == null) return;
   m_WaveMaterial.SetFloat("_WaveWidth", waveWidth);
   m_WaveMaterial.SetFloat("_CenterX", m_CenterX);
   m_WaveMaterial.SetFloat("_CenterY", m_CtenterY);
   Graphics.Blit(source, destination, m_WaveMaterial);
 }
}

来源：https://blog.csdn.net/clzmin/article/details/73696551