标签：游戏开发 cg语言 shader unity3d 屏幕特效
说起夜视仪，肯定都会想到屏幕上发绿的游戏特效先来看下我们的实现效果：
感觉还不错
本次shader需要用到三种贴图：
1.晕影贴图：
给人一种正带着夜视仪的感觉
2.噪波贴图：
产生雪花状噪波
3.扫描线贴图：
增加夜视仪的真实感
先建立一个shader
先浏览一下变量：
_ScanLineTileTex; 扫描线效果的贴图
噪波贴图：
基于两种颜色或材质的交互创建曲面的随机扰动
通过对两种颜色随机混合,生成噪波效果
_NoiseTex; 噪波贴图
_VignetteTex;晕影贴图
_Contrast;对比度
颜色的鲜明程度
_Brightness;亮度
_RandomValue;随机值，用在噪波贴图随机uv扰动
_distortion;桶形畸变的扭曲程度
_scale;屏幕放缩比例
_ScanLineTileAmount;扫描线数量（不是确切数量，指程度大小）
_NoiseXSpeed;噪波x方向速度
_NoiseYSpeed;噪波y方向速度
_NightVisionColor;夜视仪颜色
Properties {
_MainTex ("Base (RGB)", 2D) = "white" {}
_Contrast("Contrast", Range(0, 4)) = 2
_Brightness ("Brightness", Range(0, 2)) = 1
_NightVisionColor ("Night Vision Color", Color) = (1, 1, 1, 1)
_RandomValue ("RandomValue", Float) = 0
_distortion("distortion", Float) = 0.2
_scale("scale", Float) = 0.8
_VignetteTex("Vignette Texture", 2D) = "white" {}
_ScanLineTileTex("Scan Line Tile Texture", 2D) = "white" {}
_ScanLineTileAmount("Scan Line Tile Amount", Float) = 4.0
_NoiseTex("Noise Texture", 2D) = "white" {}
_NoiseXSpeed("Noise X Speed", Float) = 100.0
_NoiseYSpeed("Noise Y Speed", Float) = 100.0
}
SubSha我们还要声明一下：
#pragma vertex vert_img 传入的像素信息为vert_img
#pragma fragment frag
片元着色函数为frag
#pragma fragmentoption ARB_precision_hint_fastest
片元着色选项。ARB_precision_hint_fastest使用这个标志可以fp16的对像素进行运算，加快渲染
#pragma vertex vert_img #pragma fragment frag #pragma fragmentoption ARB_precision_hint_fastest
float2 barrelDistortion(float2 coord)
{
float2 h = coord.xy - float2(0.5, 0.5);
float r2 = h.x * h.x + h.y * h.y;
float f = 1.0 + r2 * (_distortion * sqrt(r2));
return f * _scale * h + 0.5;
}
然后我们开始在frag函数中对片元进行着色
从刚才的桶形畸变函数传出经过处理得uv值distortedUV
获得当前传入摄像头的像素信息renderTex
获取晕影贴图像素信息
vignetteTex = tex2D(_VignetteTex, distortedUV);
扫描线uv 可控扫描线数量
scanLinesUV = half2(i.uv.x * _ScanLineTileAmount, i.uv.y * _ScanLineTileAmount);
获取扫描线贴图像素信息
scanLineTex = tex2D(_ScanLineTileTex, scanLinesUV);
噪波贴图uv
根据时间与随机值变换uv产生扰动效果
noiseUV = half2(i.uv.x + (_RandomValue * _SinTime.z * _NoiseXSpeed),i.uv.y + (_Time.x * _NoiseYSpeed));
获取噪波贴图像素信息
fixed4 noiseTex = tex2D(_NoiseTex, noiseUV);
lum 即 luminosity 亮度值
lum = dot (fixed3(0.299, 0.587, 0.114), renderTex.rgb);
lum += _Brightness;//加上可自控的亮度
使饱和度调为零，变成黑白效果，再与夜视镜颜色混合
fixed4 finalColor = (lum *2) + _NightVisionColor;
再与三种贴图颜色混合得到最终颜色值
finalColor = pow(finalColor, _Contrast);
finalColor *= vignetteTex;
finalColor *= scanLineTex * noiseTex;
shader就ok了
fixed4 frag(v2f_img i/*像素信息*/) : COLOR// 片元着色函数
{
half2 distortedUV = barrelDistortion(i.uv); //桶形畸变uv
fixed4 renderTex = tex2D(_MainTex, distortedUV);
fixed4 vignetteTex = tex2D(_VignetteTex, distortedUV); //晕影贴图
//扫描线uv 可控扫描线数量
half2 scanLinesUV = half2(i.uv.x * _ScanLineTileAmount, i.uv.y * _ScanLineTileAmount);//_ScanLineTileAmount大小无限制
fixed4 scanLineTex = tex2D(_ScanLineTileTex, scanLinesUV);
//噪波贴图uv
half2 noiseUV = half2(i.uv.x + (_RandomValue * _SinTime.z * _NoiseXSpeed),i.uv.y + (_Time.x * _NoiseYSpeed));
fixed4 noiseTex = tex2D(_NoiseTex, noiseUV);
//lum = luminosity 亮度
fixed lum = dot (fixed3(0.299, 0.587, 0.114), renderTex.rgb);
lum += _Brightness;//加上可自控的亮度
//饱和度调为零，变成黑白效果，再与夜视镜颜色混合
fixed4 finalColor = (lum *2) + _NightVisionColor;//
finalColor = pow(finalColor, _Contrast);//对比度
finalColor *= vignetteTex;//与晕影贴图混合
finalColor *= scanLineTex * noiseTex;
return finalColor;
}
接下来看看放入摄像头中的c#脚本
建立一个c#脚本
先赋予变量，与上面的shader的变量都差不多，
这就是一会要传入shader的值
<span style="font-size:12px;"> #region Variables public Shader nightVisionShader; public float contrast = 2.0f; public float brightness = 1.0f; public Color nightVisionColor = Color.white; public Texture2D vignetteTexture; public Texture2D scanLineTexture; public float scanLineTileAmount = 4.0f; public Texture2D nightVisionNoise; public float noiseXSpeed = 100.0f; public float noiseYSpeed = 100.0f; public float distortion = 0.2f; public float scale = 0.8f; private float randomValue = 0.0f; private Material curMaterial; #endregion</span>
动态建立一个纹理
<span style="font-size:12px;"> #region Properties
Material material
{
get
{
if(curMaterial == null)
{
curMaterial = new Material(nightVisionShader);
curMaterial.hideFlags = HideFlags.HideAndDontSave;
}
return curMaterial;
}
}
#endregion</span>依旧需要 OnRenderImage()这个函数抓取摄像机的图像
然后我们把各种变量传入shader
通过 Graphics.Blit() 这个函数
可以经过shader的变换处理在输出到我们的显示器中
<span style="font-size:12px;">void OnRenderImage(RenderTexture sourceTexture, RenderTexture destTexture)
{
if(nightVisionShader != null)
{
material.SetFloat("_Contrast", contrast);
material.SetFloat("_Brightness", brightness);
material.SetColor("_NightVisionColor", nightVisionColor);
material.SetFloat("_RandomValue", randomValue);
material.SetFloat("_distortion", distortion);
material.SetFloat("_scale",scale);
if(vignetteTexture)
{
material.SetTexture("_VignetteTex", vignetteTexture);
}
if(scanLineTexture)
{
material.SetTexture("_ScanLineTileTex", scanLineTexture);
material.SetFloat("_ScanLineTileAmount", scanLineTileAmount);
}
if(nightVisionNoise)
{
material.SetTexture("_NoiseTex", nightVisionNoise);
material.SetFloat("_NoiseXSpeed", noiseXSpeed);
material.SetFloat("_NoiseYSpeed", noiseYSpeed);
}
Graphics.Blit(sourceTexture, destTexture, material);
}
else
{
Graphics.Blit(sourceTexture, destTexture);
}
}</span>
以下全部代码：
c#：
<span style="font-size:12px;">using UnityEngine;
using System.Collections;
public class night : MonoBehaviour
{
#region Variables
public Shader nightVisionShader;
public float contrast = 2.0f;
public float brightness = 1.0f;
public Color nightVisionColor = Color.white;
public Texture2D vignetteTexture;
public Texture2D scanLineTexture;
public float scanLineTileAmount = 4.0f;
public Texture2D nightVisionNoise;
public float noiseXSpeed = 100.0f;
public float noiseYSpeed = 100.0f;
public float distortion = 0.2f;
public float scale = 0.8f;
private float randomValue = 0.0f;
private Material curMaterial;
#endregion
#region Properties
Material material
{
get
{
if(curMaterial == null)
{
curMaterial = new Material(nightVisionShader);
curMaterial.hideFlags = HideFlags.HideAndDontSave;
}
return curMaterial;
}
}
#endregion
void Start()
{
if(!SystemInfo.supportsImageEffects)
{
enabled = false;
return;
}
if(!nightVisionShader && !nightVisionShader.isSupported)
{
enabled = false;
}
}
void OnRenderImage(RenderTexture sourceTexture, RenderTexture destTexture)
{
if(nightVisionShader != null)
{
material.SetFloat("_Contrast", contrast);
material.SetFloat("_Brightness", brightness);
material.SetColor("_NightVisionColor", nightVisionColor);
material.SetFloat("_RandomValue", randomValue);
material.SetFloat("_distortion", distortion);
material.SetFloat("_scale",scale);
if(vignetteTexture)
{
material.SetTexture("_VignetteTex", vignetteTexture);
}
if(scanLineTexture)
{
material.SetTexture("_ScanLineTileTex", scanLineTexture);
material.SetFloat("_ScanLineTileAmount", scanLineTileAmount);
}
if(nightVisionNoise)
{
material.SetTexture("_NoiseTex", nightVisionNoise);
material.SetFloat("_NoiseXSpeed", noiseXSpeed);
material.SetFloat("_NoiseYSpeed", noiseYSpeed);
}
Graphics.Blit(sourceTexture, destTexture, material);
}
else
{
Graphics.Blit(sourceTexture, destTexture);
}
}
void Update()
{
contrast = Mathf.Clamp(contrast, 0f,4f);
brightness = Mathf.Clamp(brightness, 0f, 2f);
randomValue = Random.Range(-1f,1f);
distortion = Mathf.Clamp(distortion, -1f,1f);
scale = Mathf.Clamp(scale, 0f, 3f);
}
void OnDisable()
{
if(curMaterial)
{
DestroyImmediate(curMaterial);
}
}
}</span>
shader：
<span style="font-size:12px;">Shader "Custom/shaderTest" {
Properties {
_MainTex ("Base (RGB)", 2D) = "white" {}
_Contrast("Contrast", Range(0, 4)) = 2
_Brightness ("Brightness", Range(0, 2)) = 1
_NightVisionColor ("Night Vision Color", Color) = (1, 1, 1, 1)
_RandomValue ("RandomValue", Float) = 0
_distortion("distortion", Float) = 0.2
_scale("scale", Float) = 0.8
_VignetteTex("Vignette Texture", 2D) = "white" {}
_ScanLineTileTex("Scan Line Tile Texture", 2D) = "white" {}
_ScanLineTileAmount("Scan Line Tile Amount", Float) = 4.0
_NoiseTex("Noise Texture", 2D) = "white" {}
_NoiseXSpeed("Noise X Speed", Float) = 100.0
_NoiseYSpeed("Noise Y Speed", Float) = 100.0
}
SubShader {
Pass {
Tags { "RenderType"="Opaque" }
LOD 200
CGPROGRAM
#pragma vertex vert_img
#pragma fragment frag
#pragma fragmentoption ARB_precision_hint_fastest//使用这个标志可以fp16的对像素进行运算
#include "UnityCG.cginc"
uniform sampler2D _MainTex;
uniform sampler2D _ScanLineTileTex;//扫描线效果的贴图
//噪波贴图基于两种颜色或材质的交互创建曲面的随机扰动
//通过对两种颜色随机混合,生成噪波效果
uniform sampler2D _NoiseTex;//噪波贴图
uniform sampler2D _VignetteTex;//装饰图案，小插图，此处为晕影贴图
fixed _Contrast;//对比度
fixed _Brightness;//亮度
fixed _RandomValue;//随机值，用在噪波贴图随机uv扰动
fixed _distortion;//扭曲
fixed _scale;//屏幕比例
fixed _ScanLineTileAmount;//扫描线数量
fixed _NoiseXSpeed;//噪波x方向速度
fixed _NoiseYSpeed;//噪波y方向速度
fixed4 _NightVisionColor;//夜视镜颜色
struct Input {
float2 uv_MainTex;
};
float2 barrelDistortion(float2 coord)
{
float2 h = coord.xy - float2(0.5, 0.5);
float r2 = h.x * h.x + h.y * h.y;
float f = 1.0 + r2 * (_distortion * sqrt(r2));
return f * _scale * h + 0.5;
}
fixed4 frag(v2f_img i/*像素信息*/) : COLOR// 片元着色函数
{
half2 distortedUV = barrelDistortion(i.uv); //桶形畸变uv
fixed4 renderTex = tex2D(_MainTex, distortedUV);
fixed4 vignetteTex = tex2D(_VignetteTex, distortedUV); //晕影贴图
//扫描线uv 可控扫描线数量
half2 scanLinesUV = half2(i.uv.x * _ScanLineTileAmount, i.uv.y * _ScanLineTileAmount);//_ScanLineTileAmount大小无限制
fixed4 scanLineTex = tex2D(_ScanLineTileTex, scanLinesUV);
//噪波贴图uv
half2 noiseUV = half2(i.uv.x + (_RandomValue * _SinTime.z * _NoiseXSpeed),i.uv.y + (_Time.x * _NoiseYSpeed));
fixed4 noiseTex = tex2D(_NoiseTex, noiseUV);
//lum = luminosity 亮度
fixed lum = dot (fixed3(0.299, 0.587, 0.114), renderTex.rgb);
lum += _Brightness;//加上可自控的亮度
//饱和度调为零，变成黑白效果，再与夜视镜颜色混合
fixed4 finalColor = (lum *2) + _NightVisionColor;//
finalColor = pow(finalColor, _Contrast);//对比度
finalColor *= vignetteTex;//与晕影贴图混合
finalColor *= scanLineTex * noiseTex;
return finalColor;
}
ENDCG
}
}
FallBack "Diffuse"
} </span>
------------- by wolf96
标签：游戏开发 cg语言 shader unity3d 屏幕特效
原文地址：http://blog.csdn.net/wolf96/article/details/41964665
