标签：游戏开发 unity3d cg语言 shader 屏幕特效
做出这种古老效果，需要： 颜色发黄， 晕影效果， 灰尘与刮痕的效果。
建立一个c#脚本，将要放在摄像头中
先声明变量
oldFilmShader 所需shader（一会需要编写）
OldFilmEffectAmount 古老的程度（最后做插值的程度值）
sepiaColor 屏幕的颜色（调至黑黄）
vigentteTexture 老电影式基本贴图
vigentteAmount 所占比重
scratchesTexture 刮痕贴图
scratchesYspeed 刮痕y方向移动速度
scratchesXspeed 刮痕x方向移动速度
Texture2D dustTexture; 灰尘贴图
dustYSpeed 灰尘y方向移动速度
dustXSpeed 灰尘x方向移动速度
randomValue 随机值
public Shader oldFilmShader;
public float OldFilmEffectAmount = 1.0f;
public Color sepiaColor = Color.white;
public Texture2D vigentteTexture;
public float vigentteAmount = 1.0f;
public Texture2D scratchesTexture;
public float scratchesYspeed = 10.0f;
public float scratchesXspeed = 10.0f;
public Texture2D dustTexture;
public float dustYSpeed = 10.0f;
public float dustXSpeed = 10.0f;
private Material curMaterial;
private float randomValue;
void OnRenderImage(RenderTexture sourceTex, RenderTexture destTex)
{
if (oldFilmShader != null)
{
material.SetColor("_SepiaColor", sepiaColor);
material.SetFloat("_VigentteAmount", vigentteAmount);
material.SetFloat("_OldFilmEffectAmount", OldFilmEffectAmount);
if (vigentteTexture)
{
material.SetTexture("_VigentteTex", vigentteTexture);
}
if (scratchesTexture)
{
material.SetTexture("_ScratchesTex", scratchesTexture);
material.SetFloat("_ScratchesYSpeed", scratchesYspeed);
material.SetFloat("_ScratchesXSpeed", scratchesXspeed);
}
if (dustTexture)
{
material.SetTexture("_DustTex", dustTexture);
material.SetFloat("_DustXSpeed", dustXSpeed);
material.SetFloat("_DustYSpeed", dustYSpeed);
material.SetFloat("_RandomValue", randomValue);
}
Graphics.Blit(sourceTex, destTex, material);
}
else
{
Graphics.Blit(sourceTex, destTex);
}
}
再看shader
声明变量
distortion 扭曲程度
cubicDistortion 三维扭曲程度
Properties
{
_MainTex ("Base(RGB)", 2D) = "white" {}
_VignetteTex ("VignetteTexture", 2D) = "white"{}
_ScratchesTex ("ScartchesTexture", 2D) = "white"{}
_DustTex ("DustTexture", 2D) = "white"{}
_SepiaColor ("SepiaColor", Color) = (1,1,1,1)
_EffectAmount ("OldFilmEffectAmount", Range(0,1)) = 1.0
_VignetteAmount ("Vignette Opacity", Range(0,1)) = 1.0
_ScratchesYSpeed ("ScratchesYSpeed", Float) = 10.0
_ScratchesXSpeed ("ScratchesXSpeed", Float) = 10.0
_dustXSpeed ("DustXSpeed", Float) = 10.0
_dustYSpeed ("DustYSpeed", Float) = 10.0
_RandomValue ("RandomValue", Float) = 1.0
_Contrast ("Contrast", Float) = 3.0
_distortion ("Distortion", Float) = 0.2
_cubicDistortion ("CubicDistortion", Float) = 0.6
_scale ("Scale(Zoom)", Float) = 0.8
}
float2 barrelDistortion(float2 coord)
{
// Inspired by SynthEyes lens distortion algorithm
// See http://www.ssontech.com/content/lensalg.htm
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 + _cubicDistortion * sqrt(r2));
return f * _scale * h + 0.5;
}
从v2f_img i中获取图像的颜色和uv值
通过上面的barrelDistortion()函数获得扭曲的uv
刮痕的uv
对刮痕的uv进行变换，使之随时间移动
lum 求图像的饱和度
最终颜色初定义 = 饱和度+所定义颜色（浮动的明暗度（线性插值））
求颜色的对比度次方
不同的层合在一起构成屏幕最终特效
先与老电影式基本贴图做插值混合
然后与刮痕混合，与白色的插值来制造刮痕的闪烁效果
与灰尘相乘混合，与白色的插值来制造灰尘的闪烁效果
最后与图像的本来面貌做插值
得到最终颜色
fixed4 frag(v2f_img i) : COLOR
{
//Get the colors from the RenderTexture and the uv's
//from the v2f_img struct
half2 distortedUV = barrelDistortion(i.uv);
distortedUV = half2(i.uv.x, i.uv.y + (_RandomValue * _SinTime.z * 0.005));
fixed4 renderTex = tex2D(_MainTex, i.uv);
//Get the pixels from the Vignette Texture
fixed4 vignetteTex = tex2D(_VignetteTex, i.uv);
//Process the Scratches UV and pixels
half2 scratchesUV = half2(i.uv.x + (_RandomValue * _SinTime.z * _ScratchesXSpeed),
i.uv.y + (_Time.x * _ScratchesYSpeed));
fixed4 scratchesTex = tex2D(_ScratchesTex, scratchesUV);
//Process the Dust UV and pixels
half2 dustUV = half2(i.uv.x + (_RandomValue * (_SinTime.z * _dustXSpeed)),
i.uv.y + (_RandomValue * (_SinTime.z * _dustYSpeed)));
fixed4 dustTex = tex2D(_DustTex, dustUV);
// get the luminosity values from the render texture using the YIQ values.
fixed lum = dot (fixed3(0.299, 0.587, 0.114), renderTex.rgb);
//Add the constant color to the lum values
fixed4 finalColor = lum + lerp(_SepiaColor, _SepiaColor +
fixed4(0.1f,0.1f,0.1f,1.0f), _RandomValue);
finalColor = pow(finalColor, _Contrast);
//Create a constant white color we can use to adjust opacity of effects
fixed3 constantWhite = fixed3(1,1,1);
//Composite together the different layers to create finsl Screen Effect
finalColor = lerp(finalColor, finalColor * vignetteTex, _VignetteAmount);
finalColor.rgb *= lerp(scratchesTex, constantWhite, (_RandomValue));
finalColor.rgb *= lerp(dustTex.rgb, constantWhite, (_RandomValue * _SinTime.z));
finalColor = lerp(renderTex, finalColor, _EffectAmount);
return finalColor;
}
代码如下
using UnityEngine;
using System.Collections;
public class ShaderTest : MonoBehaviour
{
#region Variables
public Shader oldFilmShader;
public float OldFilmEffectAmount = 1.0f;
public Color sepiaColor = Color.white;
public Texture2D vigentteTexture;
public float vigentteAmount = 1.0f;
public Texture2D scratchesTexture;
public float scratchesYspeed = 10.0f;
public float scratchesXspeed = 10.0f;
public Texture2D dustTexture;
public float dustYSpeed = 10.0f;
public float dustXSpeed = 10.0f;
private Material curMaterial;
private float randomValue;
#endregion
#region Properties
public Material material
{
get
{
if (curMaterial == null)
{
curMaterial = new Material(oldFilmShader);
curMaterial.hideFlags = HideFlags.HideAndDontSave;
}
return curMaterial;
}
}
#endregion
void OnRenderImage(RenderTexture sourceTex, RenderTexture destTex)
{
if (oldFilmShader != null)
{
material.SetColor("_SepiaColor", sepiaColor);
material.SetFloat("_VigentteAmount", vigentteAmount);
material.SetFloat("_OldFilmEffectAmount", OldFilmEffectAmount);
if (vigentteTexture)
{
material.SetTexture("_VigentteTex", vigentteTexture);
}
if (scratchesTexture)
{
material.SetTexture("_ScratchesTex", scratchesTexture);
material.SetFloat("_ScratchesYSpeed", scratchesYspeed);
material.SetFloat("_ScratchesXSpeed", scratchesXspeed);
}
if (dustTexture)
{
material.SetTexture("_DustTex", dustTexture);
material.SetFloat("_DustXSpeed", dustXSpeed);
material.SetFloat("_DustYSpeed", dustYSpeed);
material.SetFloat("_RandomValue", randomValue);
}
Graphics.Blit(sourceTex, destTex, material);
}
else
{
Graphics.Blit(sourceTex, destTex);
}
}
// Use this for initialization
void Start()
{
if (SystemInfo.supportsImageEffects == false)
{
enabled = false;
return;
}
if (oldFilmShader != null && oldFilmShader.isSupported == false)
{
enabled = false;
}
}
// Update is called once per frame
void Update()
{
vigentteAmount = Mathf.Clamp01(vigentteAmount);
OldFilmEffectAmount = Mathf.Clamp(OldFilmEffectAmount, 0f, 1.5f);
randomValue = Random.Range(-1f, 1f);
}
}
shader:
Shader "Custom/TestShader" {
Properties
{
_MainTex ("Base(RGB)", 2D) = "white" {}
_VignetteTex ("VignetteTexture", 2D) = "white"{}
_ScratchesTex ("ScartchesTexture", 2D) = "white"{}
_DustTex ("DustTexture", 2D) = "white"{}
_SepiaColor ("SepiaColor", Color) = (1,1,1,1)
_EffectAmount ("OldFilmEffectAmount", Range(0,1)) = 1.0
_VignetteAmount ("Vignette Opacity", Range(0,1)) = 1.0
_ScratchesYSpeed ("ScratchesYSpeed", Float) = 10.0
_ScratchesXSpeed ("ScratchesXSpeed", Float) = 10.0
_dustXSpeed ("DustXSpeed", Float) = 10.0
_dustYSpeed ("DustYSpeed", Float) = 10.0
_RandomValue ("RandomValue", Float) = 1.0
_Contrast ("Contrast", Float) = 3.0
_distortion ("Distortion", Float) = 0.2
_cubicDistortion ("CubicDistortion", Float) = 0.6
_scale ("Scale(Zoom)", Float) = 0.8
}
SubShader
{
Pass
{
CGPROGRAM
#pragma vertex vert_img
#pragma fragment frag
#pragma fragmentoption ARB_precision_hint_fastest
#include "UnityCG.cginc"
uniform sampler2D _MainTex;
uniform sampler2D _VignetteTex;
uniform sampler2D _ScratchesTex;
uniform sampler2D _DustTex;
fixed4 _SepiaColor;
fixed _VignetteAmount;
fixed _ScratchesYSpeed;
fixed _ScratchesXSpeed;
fixed _dustXSpeed;
fixed _dustYSpeed;
fixed _EffectAmount;
fixed _RandomValue;
fixed _Contrast;
float _distortion;
float _cubicDistortion;
float _scale;
float2 barrelDistortion(float2 coord)
{
// Inspired by SynthEyes lens distortion algorithm
// See http://www.ssontech.com/content/lensalg.htm
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 + _cubicDistortion * sqrt(r2));
return f * _scale * h + 0.5;
}
fixed4 frag(v2f_img i) : COLOR
{
//Get the colors from the RenderTexture and the uv's
//from the v2f_img struct
half2 distortedUV = barrelDistortion(i.uv);
distortedUV = half2(i.uv.x, i.uv.y + (_RandomValue * _SinTime.z * 0.005));
fixed4 renderTex = tex2D(_MainTex, i.uv);
//Get the pixels from the Vignette Texture
fixed4 vignetteTex = tex2D(_VignetteTex, i.uv);
//Process the Scratches UV and pixels
half2 scratchesUV = half2(i.uv.x + (_RandomValue * _SinTime.z * _ScratchesXSpeed),
i.uv.y + (_Time.x * _ScratchesYSpeed));
fixed4 scratchesTex = tex2D(_ScratchesTex, scratchesUV);
//Process the Dust UV and pixels
half2 dustUV = half2(i.uv.x + (_RandomValue * (_SinTime.z * _dustXSpeed)),
i.uv.y + (_RandomValue * (_SinTime.z * _dustYSpeed)));
fixed4 dustTex = tex2D(_DustTex, dustUV);
// get the luminosity values from the render texture using the YIQ values.
fixed lum = dot (fixed3(0.299, 0.587, 0.114), renderTex.rgb);
//Add the constant color to the lum values
fixed4 finalColor = lum + lerp(_SepiaColor, _SepiaColor +
fixed4(0.1f,0.1f,0.1f,1.0f), _RandomValue);
finalColor = pow(finalColor, _Contrast);
//Create a constant white color we can use to adjust opacity of effects
fixed3 constantWhite = fixed3(1,1,1);
//Composite together the different layers to create finsl Screen Effect
finalColor = lerp(finalColor, finalColor * vignetteTex, _VignetteAmount);
finalColor.rgb *= lerp(scratchesTex, constantWhite, (_RandomValue));
finalColor.rgb *= lerp(dustTex.rgb, constantWhite, (_RandomValue * _SinTime.z));
finalColor = lerp(renderTex, finalColor, _EffectAmount);
return finalColor;
}
ENDCG
}
}
FallBack off
}
图片资源：
vigentteTexture
scratchesTexture
<span style="font-size:14px;color:#FF6600;">dustTexture</span>
--------by wolf96
标签：游戏开发 unity3d cg语言 shader 屏幕特效
原文地址：http://blog.csdn.net/wolf96/article/details/41695523
