UnityShader3转圈 冷却 UnityShader3实现转圈与冷却效果
宏哥1995 人气:0参考链接:OpenGL Shader实例分析(3)等待标识效果
一、转圈效果
效果图:
如何实现一个圆绕中心点运动呢?原理很简单,就是随着时间的流逝,起始边固定,而另一条边不断地移动,弧度从0到2*PI,只需求出移动边与圆边的交点,然后画圆即可。至于这个交点,因为圆心的uv为(0.5,0.5),所以交点的坐标就是(0.5 - r * cos(a) , 0.5 + r * sin(a))。
Shader "Custom/Loading" { Properties { _Color ("Color", Color) = (0, 1, 0, 1) _Speed ("Speed", Range(1, 10)) = 1 _Radius ("Radius", Range(0, 0.5)) = 0.3 } SubShader { Tags { "Queue" = "Transparent" } Blend SrcAlpha OneMinusSrcAlpha ZWrite Off Pass { CGPROGRAM #pragma vertex vert #pragma fragment frag #include "UnityCG.cginc" #define PI 3.14159 struct appdata { float4 vertex : POSITION; float2 uv : TEXCOORD0; }; struct v2f { float4 vertex : SV_POSITION; float2 uv : TEXCOORD0; }; fixed4 _Color; half _Speed; fixed _Radius; fixed4 circle(float2 uv, float2 center, float radius) { //if(pow(uv.x - center.x, 2) + pow(uv.y - center.y, 2) < pow(radius, 2)) return _Color; if(length(uv - center) < radius) return _Color; else return fixed4(0, 0, 0, 0); } v2f vert (appdata v) { v2f o; o.vertex = mul(UNITY_MATRIX_MVP, v.vertex); o.uv = v.uv; return o; } fixed4 frag (v2f i) : SV_Target { fixed4 finalCol = (0, 0, 0, 0); for(int count = 7; count > 1; count--) { half radian = fmod(_Time.y * _Speed + count * 0.5, 2 * PI);//弧度 half2 center = half2(0.5 - _Radius * cos(radian), 0.5 + _Radius * sin(radian)); finalCol += circle(i.uv, center, count * 0.01); } return finalCol; } ENDCG } } }
二.冷却效果
效果图:
参考上面那张原理图,稍加修改就可以了。
Shader "Custom/Cooling" { Properties { _MainTex ("Texture", 2D) = "white" {} _Speed ("Speed", Range(1, 10)) = 1 _Color ("Color", Color) = (0, 0, 0, 1) } SubShader { Pass { CGPROGRAM #pragma vertex vert #pragma fragment frag #include "UnityCG.cginc" #define PI 3.142 struct appdata { float4 vertex : POSITION; float2 uv : TEXCOORD0; }; struct v2f { float4 vertex : SV_POSITION; float2 uv : TEXCOORD0; }; sampler2D _MainTex; float4 _MainTex_ST; half _Speed; fixed4 _Color; v2f vert (appdata v) { v2f o; o.vertex = mul(UNITY_MATRIX_MVP, v.vertex); o.uv = TRANSFORM_TEX(v.uv, _MainTex); return o; } fixed4 frag (v2f i) : SV_Target { fixed4 col = tex2D(_MainTex, i.uv); //以正中间为中心,所以将uv范围映射到(-0.5, 0.5) float2 uv = i.uv - float2(0.5, 0.5); //atan2(y, x):反正切,y/x的反正切范围在[-π, π]内 //-1用于控制方向 float radian = atan2(uv.y, uv.x) * -1 + PI; float2 radian2 = fmod(_Time.y * _Speed, 2 * PI); fixed v = step(radian, radian2); if(v > 0) return col; else return col * _Color; } ENDCG } } }
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