Unity Shader实现跳动的心脏

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我是靠谱客的博主健壮小蝴蝶，这篇文章主要介绍Unity Shader实现跳动的心脏，现在分享给大家，希望可以做个参考。

之前没有学shader的时候，看着别人做出来的效果，感觉好厉害的样子。

最近几天在恶补shader，学了点皮毛后就发现，这东西简单的很...

不啰嗦，直接进入正题：

思路：

1，在shader中设置两个变量,_WidthFactor和_HeightFactor，用来接收脚本中传递的参数，计算顶点的扩张幅度

2，在脚本中设置两条曲线AnimationCurve,分别设置定点的扩张幅度

思路很简单，直接上代码

Shader：

复制代码

Shader "MyShader/Effect/Heart"
{
	Properties
	{
		_MainTex ("Texture", 2D) = "white" {}
		_HeightFactor("HeightFactor",Range(0,0.5))=0
		_WidthFactor("WidthFactor",Range(0,0.5))=0.2
	}
	SubShader
	{
		Tags { "RenderType"="Opaque" }
		LOD 100
		Blend SrcAlpha OneMinusSrcAlpha

Pass
		{
			CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag
			// make fog work
			#pragma multi_compile_fog
			
			#include "UnityCG.cginc"

struct appdata
			{
				float4 vertex : POSITION;
				float2 uv : TEXCOORD0;
			};

struct v2f
			{
				float2 uv : TEXCOORD0;
				UNITY_FOG_COORDS(1)
				float4 vertex : SV_POSITION;
			};

sampler2D _MainTex;
			float4 _MainTex_ST;
			fixed _HeightFactor;
			fixed _WidthFactor;
			
			v2f vert (appdata v)
			{
				v2f o;
				float2 xy = float2(v.vertex.x*(1 - _WidthFactor), v.vertex.y*(1 - _HeightFactor));
				float4 vertex = float4(xy,v.vertex.z,v.vertex.w);
				o.vertex = mul(UNITY_MATRIX_MVP, vertex);
				o.uv = TRANSFORM_TEX(v.uv, _MainTex);
				UNITY_TRANSFER_FOG(o,o.vertex);
				return o;
			}
			
			fixed4 frag (v2f i) : SV_Target
			{
				fixed4 col = tex2D(_MainTex, i.uv);
				return col;
			}
			ENDCG
		}
	}
}

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Shader "MyShader/Effect/Heart"
{
	Properties
	{
		_MainTex ("Texture", 2D) = "white" {}
		_HeightFactor("HeightFactor",Range(0,0.5))=0
		_WidthFactor("WidthFactor",Range(0,0.5))=0.2
	}
	SubShader
	{
		Tags { "RenderType"="Opaque" }
		LOD 100
		Blend SrcAlpha OneMinusSrcAlpha

		Pass
		{
			CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag
			// make fog work
			#pragma multi_compile_fog
			
			#include "UnityCG.cginc"

			struct appdata
			{
				float4 vertex : POSITION;
				float2 uv : TEXCOORD0;
			};

			struct v2f
			{
				float2 uv : TEXCOORD0;
				UNITY_FOG_COORDS(1)
				float4 vertex : SV_POSITION;
			};

			sampler2D _MainTex;
			float4 _MainTex_ST;
			fixed _HeightFactor;
			fixed _WidthFactor;
			
			v2f vert (appdata v)
			{
				v2f o;
				float2 xy = float2(v.vertex.x*(1 - _WidthFactor), v.vertex.y*(1 - _HeightFactor));
				float4 vertex = float4(xy,v.vertex.z,v.vertex.w);
				o.vertex = mul(UNITY_MATRIX_MVP, vertex);
				o.uv = TRANSFORM_TEX(v.uv, _MainTex);
				UNITY_TRANSFER_FOG(o,o.vertex);
				return o;
			}
			
			fixed4 frag (v2f i) : SV_Target
			{
				fixed4 col = tex2D(_MainTex, i.uv);
				return col;
			}
			ENDCG
		}
	}
}

重点就是三行代码

复制代码

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float2 xy = float2(v.vertex.x*(1 - _WidthFactor), v.vertex.y*(1 - _HeightFactor));
float4 vertex = float4(xy,v.vertex.z,v.vertex.w);
o.vertex = mul(UNITY_MATRIX_MVP, vertex);

下面是C#控制脚本：

复制代码

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using UnityEngine;
using System.Collections;

public class Heart : MonoBehaviour {

	[SerializeField]
	public AnimationCurve width;
	[SerializeField]
	public AnimationCurve height;

	private UIWidget mUIwg;
	private Material mMat;

	// Use this for initialization
	void Start () {
		mUIwg = gameObject.GetComponent<UIWidget>();
	}
	
	// Update is called once per frame
	void Update () {
		float time = Time.time % 1.0f;
		SetShaderArg(width.Evaluate(time),height.Evaluate(time));
	}

	bool SetShaderArg(float w,float h)
	{
		if (mUIwg)
		{
			if (mUIwg.drawCall==null)
				return false;
			mMat = mUIwg.drawCall.dynamicMaterial;

			mMat.SetFloat("_WidthFactor",w);
			mMat.SetFloat("_HeightFactor", h);

			return true;
		}

		return false;
	}
}