Shader --- 法阵

      发现去百度拉图的时候竟然无意的拉了一张魔法阵的图，所以就想看看能不能瞎做一个东西出来

(Shader 学习中ing)

其中模拟雨点链接   ----   https://gameinstitute.qq.com/community/detail/125291

贴图链接                 ----    http://www.cnblogs.com/yfish/p/6842406.html

效果图如下，

Shader 代码：

Shader "ShaderTest/_Magic"
{
	properties
	{
		[HDR]_MainColor("Main Color",color) = (1,1,1,1)
		_MainTex("Main Texcoord",2D) = "while" {}
		_StarTex("Star Texcoord",2D) = "while" {}
		_Discard("Discard Value",range(0,9)) = 0
		_NormalScale("Noraml Scale",range(1,2)) = 0.1
	}

	SubShader
	{
		Tags{"RenderType"="Opaque" "Queue"="Transparent"}
		LOD 200
		pass
		{
			blend SrcAlpha one
			ZWrite off
			CGPROGRAM
			#include "UnityCG.cginc"
			#pragma vertex vert
			#pragma fragment frag
			
			struct v2f
			{
				float4 pos : POSITION;
				fixed4 uv : TEXCOORD0;
			};

			sampler2D _MainTex,_StarTex;
			float4 _MainTex_ST,_StarTex_ST;
			float4 _MainColor;
			float _Discard;
			float _NormalScale;

			v2f vert(appdata_full v)
			{
				v2f o;
				v.vertex += v.vertex * _NormalScale;
				float timer = _Time.y;
				v.vertex *= float4(_NormalScale,_NormalScale,_NormalScale,1);
				float4x4 rotate = float4x4
				(
					cos(timer),0,sin(timer),0,
					0,1,0,0,
					-sin(timer),0,cos(timer),0,
					0,0,0,1
				);
				//float4x4 scale = float4x4
				//(
				//	_NormalScale,0,0,0,
				//	0,_NormalScale,0,0,
				//	0,0,_NormalScale,0,
				//	0,0,0,1
				//);
				float4x4 MVP = UNITY_MATRIX_MVP;
				//v.vertex = mul(scale,v.vertex);
				rotate = mul(MVP,rotate);
				o.pos = mul(rotate,v.vertex);
				

				o.uv.xy = v.texcoord.xy * _MainTex_ST.xy + _MainTex_ST.zw;
				o.uv.zw = v.texcoord.xy * _StarTex_ST.xy - _Time.x ;
				return o;
			}

			fixed4 frag(v2f v) : COLOR
			{
				fixed4 color = tex2D(_MainTex,v.uv.xy);
				fixed4 star = tex2D(_StarTex,v.uv.zw);
				// 这里是因为我找到的图片没有Alpha通道，前两天刷电脑，也没有装PS - - 
				float star_c = (star.r + star.g + star.b);
				color += star;
				color *= _MainColor;
				float c = color.r + color.g + color.b;
				float2 uv = v.uv;
				// 这里是因为边缘有一条白线 不用PS的原因如上
				if(uv.x > 0.8 || uv.x < 0.2 || uv.y > 0.8 || uv.y < 0.2 || c < _Discard)
				{
					discard;
				}
				return color;
			}
			ENDCG
		}

		pass
		{
			blend SrcAlpha SrcAlpha
			ZWrite off
			CGPROGRAM
			#include "UnityCG.cginc"
			#pragma vertex vert
			#pragma fragment frag
			
			struct v2f
			{
				float4 pos : POSITION;
				fixed2 uv : TEXCOORD0;
			};

			sampler2D _MainTex;
			float4 _MainTex_ST;
			float4 _MainColor;
			float _Discard;

			v2f vert(appdata_full v)
			{
				v2f o;
				float timer = -_Time.y;
				float4x4 rotate = float4x4
				(
					cos(timer),0,sin(timer),0,
					0,1,0,0,
					-sin(timer),0,cos(timer),0,
					0,0,0,1
				);
				float4x4 MVP = UNITY_MATRIX_MVP;
				rotate = mul(MVP,rotate);

				o.pos = mul(rotate,v.vertex);
				o.uv = TRANSFORM_TEX(v.texcoord,_MainTex);
				return o;
			}

			fixed4 frag(v2f v) : COLOR
			{
				fixed4 color = tex2D(_MainTex,v.uv);
				color *= _MainColor;
				float c = color.r + color.g + color.b;
				float2 uv = v.uv;
				if(uv.x > 0.8 || uv.x < 0.2 || uv.y > 0.8 || uv.y < 0.2 || c < _Discard)
				{
					discard;
				}
				color.a = _MainColor.a;
				return color;
			}

			ENDCG
		}
	}

}

C#改变颜色代码如下

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

public class UpdateMagicColor : MonoBehaviour
{
    [Range(-1000,1000)]
    public float m_ColorUpdateSpeed;

    private Color mainColor;
    private Material magicMaterial;

    private float tempColor, startColorValue = 0.6025f, endColorValue = 1.7982f;
    private float[] color;
    private int colorIndex = 1;

    void Start()
    {
        color = new float[3];
        magicMaterial = GetComponent().material;
        mainColor = magicMaterial.GetColor("_MainColor");
        color[0] = mainColor.r;
        color[1] = mainColor.g;
        color[2] = mainColor.b;
    }

    void Update()
    {
        tempColor += m_ColorUpdateSpeed * Time.deltaTime / 1000;
        if (tempColor > endColorValue)
        {
            tempColor = endColorValue;
            m_ColorUpdateSpeed *= -1;
        }
        if (tempColor < startColorValue)
        {
            tempColor = startColorValue;
            m_ColorUpdateSpeed *= -1;
            colorIndex++;
            colorIndex = colorIndex % 3;
        }
        color[colorIndex] = tempColor;
        mainColor.r = color[0];
        mainColor.g = color[1];
        mainColor.b = color[2];
        magicMaterial.SetColor("_MainColor",mainColor);
    }
}