Unity Shader学习：2D图形绘制(蓝天白云大海)
基本是一些数学上的算法
shader部分:
Shader "Unlit/2D-Ocean"
{
Properties
{
_MainTex ("Texture", 2D) = "white" {}
_SunColor("SunColor",Color) = (1,1,1,1)
_SunRoundColor("SunRoundColor",Color) = (1,0,0,1)
_WaveColor1("WaveColor1",Color) = (1,1,1,1)
_WaveColor2("WaveColor2",Color) = (1,1,1,1)
_WaveColor3("WaveColor3",Color) = (1,1,1,1)
_WaveColor4("WaveColor4",Color) = (1,1,1,1)
_WaveColor5("WaveColor5",Color) = (1,1,1,1)
_SkyColor("SkyColor",Color)=(0,1,0,1)
_CloudPos1("CloudPos1",Vector)=(0,0,0,0)
_CloudPos2("CloudPos2",Vector) = (0,0,0,0)
_CloudPos3("CloudPos3",Vector) = (0,0,0,0)
_CloudPos4("CloudPos4",Vector) = (0,0,0,0)
_CloudPos5("CloudPos5",Vector) = (0,0,0,0)
_WaveFactor1("WaveFactor1",Vector)=(0,0,0,0)
_WaveFactor2("WaveFactor2",Vector) = (0,0,0,0)
_WaveFactor3("WaveFactor3",Vector) = (0,0,0,0)
_WaveFactor4("WaveFactor4",Vector) = (0,0,0,0)
_WaveFactor5("WaveFactor5",Vector) = (0,0,0,0)
_SunPos("SunPos",Vector)=(0,0,0,0)
_SunRoundFactor("SunRoundFactor",Range(0.0,2.0)) = 0.1
_SunSize("SunSize",Range(0.0,1.0)) = 1.0
}
SubShader
{
Tags { "RenderType"="Transparent" }
LOD 100
Blend SrcAlpha OneMinusSrcAlpha
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;
};
sampler2D _MainTex;
float4 _MainTex_ST;
float4 _CloudPos1;
float4 _CloudPos2;
float4 _CloudPos3;
float4 _CloudPos4;
float4 _CloudPos5;
float4 _WaveColor1;
float4 _WaveColor2;
float4 _WaveColor3;
float4 _WaveColor4;
float4 _WaveColor5;
float4 _WaveFactor1;
float4 _WaveFactor2;
float4 _WaveFactor3;
float4 _WaveFactor4;
float4 _WaveFactor5;
float4 _SunColor;
float4 _SunRoundColor;
float4 _SunPos;
float _SunRoundFactor;
float _SunSize;
float4 _SkyColor;
//画单个圆(uv,位置，大小，抗锯齿)
float4 Circle(float2 uv, float2 center, float size, float blur) {
uv = uv - center;
uv = uv / size;
float len = length(uv);
//长度大于一个半径单位透明度为0，小于透明度为1
float val = smoothstep(1.0,1.0-blur, len);
return float4(1, 1, 1, val);
}
//画单个云
float4 DrawCloud(float2 uv, float2 center, float size) {
uv = uv - center;
uv = uv / size;
float4 col = Circle(uv, float2(0.0, 0.0), 0.2, 1);
//将圆中不想要的部分剪切掉
col = col * smoothstep(-0.1, -0.1 + 0.01, uv.y);
//圆摆放不同位置组成云
col += Circle(uv, float2(0.15, -0.05), 0.1, 1);
col += Circle(uv, float2(0.0, -0.1), 0.11, 1);
col += Circle(uv, float2(-0.15, -0.1), 0.1, 1);
col += Circle(uv, float2(-0.3, -0.08), 0.1, 1);
col += Circle(uv, float2(-0.2, 0.0), 0.15, 1);
return col;
}
//画复数云
float4 DrawClouds(float2 uv) {
uv.x += 0.03*_Time.y;
//使得左右连续
uv.x = frac(uv.x + 0.5) - 0.5;
float4 col = DrawCloud(uv, _CloudPos1.xy, 0.1);
col += DrawCloud(uv, _CloudPos2.xy, 0.12);
col += DrawCloud(uv, _CloudPos3.xy, 0.14);
col += DrawCloud(uv, _CloudPos4.xy, 0.16);
col += DrawCloud(uv, _CloudPos5.xy, 0.18);
return col;
}
//画太阳光环
float4 DrawSunCircle(float2 uv,float2 center,float size) {
uv = uv - center;
uv = uv / size;
//atan2返回点(x,y)与x轴的夹角，范围(-π,π]
//获取极坐标的θ角度
float degree = atan2(uv.y , uv.x ) + _Time.y * -0.1;
//uv向量离中心点距离
//获取极坐标的r=x2+y2开方
float len = length(uv);
//根据极坐标玫瑰线:r(θ)=a*sin(kθ)
//求得r;a为扩散幅度，k为花瓣数*0.5
float r = 0.3*abs(sin(degree*5.0));
//画花瓣
//保留r值小于到中心点距离的所有像素
float sunRound= smoothstep(r + 0.1 + _SunRoundFactor, r + _SunRoundFactor, len);
return float4(1,1,1,sunRound)*_SunRoundColor;
}
//画波浪(参数:uv,频率,振幅,整体高度,移动速度)
float4 DrawWave(float2 uv,float waveFrequency,float waveAmplitude,float waveHeight,float speed) {
uv.x += speed * _Time.y;
uv.y += sin(_Time.y+waveHeight)*0.02;
//uv.y大于sin函数的部分透明度为0，小于的部分透明度为1
float val = uv.y - sin(uv.x*waveFrequency)*waveAmplitude - waveHeight;
val = smoothstep(0.001,0.0, val);
return float4(1, 1, 1, val);
}
//画背景
float4 DrawBackground(float2 uv) {
float4 val = lerp(float4(1,1,1,1), _SkyColor, uv.y);
return val;
}
//混合图层(b为前景,a为背景)
float4 LerpImages(float4 a, float4 b) {
return float4(lerp(a, b, b.a).rgb, a.a + b.a);
}
v2f vert (appdata v)
{
v2f o;
o.vertex = UnityObjectToClipPos(v.vertex);
o.uv = TRANSFORM_TEX(v.uv, _MainTex);
return o;
}
float4 frag (v2f i) : SV_Target
{
//太阳中心
float4 sunCoreColor = Circle(i.uv, _SunPos.xy, _SunSize, 0.05)*_SunColor;
//太阳光环
float4 sunAroundColor = DrawSunCircle(i.uv, _SunPos.xy, _SunSize);
//云
float4 cloudsColor = DrawClouds(i.uv);
//波浪
float4 wave1 = DrawWave(i.uv, _WaveFactor1.x, _WaveFactor1.y, _WaveFactor1.z, _WaveFactor1.w)*_WaveColor1;
float4 wave2 = DrawWave(i.uv, _WaveFactor2.x, _WaveFactor2.y, _WaveFactor2.z, _WaveFactor2.w)*_WaveColor2;
float4 wave3 = DrawWave(i.uv, _WaveFactor3.x, _WaveFactor3.y, _WaveFactor3.z, _WaveFactor3.w)*_WaveColor3;
float4 wave4 = DrawWave(i.uv, _WaveFactor4.x, _WaveFactor4.y, _WaveFactor4.z, _WaveFactor4.w)*_WaveColor4;
float4 wave5 = DrawWave(i.uv, _WaveFactor5.x, _WaveFactor5.y, _WaveFactor5.z, _WaveFactor5.w)*_WaveColor5;
//背景
float4 backgroundColor = DrawBackground(i.uv);
//图层叠加
float4 finalColor = LerpImages(backgroundColor, sunAroundColor);
finalColor = LerpImages(finalColor, sunCoreColor);
finalColor= LerpImages(finalColor, wave1);
finalColor = LerpImages(finalColor, wave2);
finalColor = LerpImages(finalColor, wave3);
finalColor = LerpImages(finalColor, wave4);
finalColor = LerpImages(finalColor, wave5);
finalColor = LerpImages(finalColor, cloudsColor);
return finalColor;
}
ENDCG
}
}
}