Unity 动画
Unity Shader 内置时间变量
引入时间变量
| 名称 | 类型 | 描述 |
|---|---|---|
| _Time | float4 | t是自该场景加载开始所经过的时间，4个分量分别是(t/20, t, 2t, 3t) |
| _SinTime | float4 | t是时间的正弦值，(t/8, t/4, t/2, t) |
| _CosTime | float4 | t是时间的余弦值，(t/8, t/4, t/2, t) |
| unity_DeltaTime | float4 | dt是时间增量，(dt, 1/dt, smoothDt, 1/smoothDt) |
纹理动画
使用一张纹理实现的动画，用于代替复杂的粒子系统来模拟动画效果。
u方向动画与v方向动画对比
序列帧动画
代码：
Shader "Unity Shaders Book/Chapter 11/Image Sequence Animation" {
Properties {
_Color ("Color Tint", Color) = (1, 1, 1, 1)
_MainTex ("Image Sequence", 2D) = "white" {}
_HorizontalAmount ("Horizontal Amount", Float) = 8
_VerticalAmount ("Vertical Amount", Float) = 8
_Speed ("Speed", Range(1, 100)) = 30
}
SubShader {
Tags {"Queue"="Transparent" "IgnoreProjector"="True" "RenderType"="Transparent"}
Pass {
Tags { "LightMode"="ForwardBase" }
ZWrite Off
Blend SrcAlpha OneMinusSrcAlpha
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
fixed4 _Color;
sampler2D _MainTex;
float4 _MainTex_ST;
float _HorizontalAmount;
float _VerticalAmount;
float _Speed;
struct a2v {
float4 vertex : POSITION;
float2 texcoord : TEXCOORD0;
};
struct v2f {
float4 pos : SV_POSITION;
float2 uv : TEXCOORD0;
};
v2f vert (a2v v) {
v2f o;
//将顶点坐标转换到裁剪空间坐标系并且
o.pos = mul(UNITY_MATRIX_MVP, v.vertex);
//o.texcoord = v.texcoord.xy *_MainTex_ST.xy+_MainTex_ST.zw
//将纹理坐标映射到顶点上以及zw偏移
o.uv = TRANSFORM_TEX(v.texcoord, _MainTex);
return o;
}
fixed4 frag (v2f i) : SV_Target {
float time = floor(_Time.y * _Speed);
float row = floor(time / _HorizontalAmount); // /运算获取当前行
float column = time - row * _HorizontalAmount; // %运算获取当前列
//首先把原纹理坐标i.uv按行数和列数进行等分，然后使用当前的行列进行偏移
half2 uv = i.uv + half2(column, -row);
uv.x /= _HorizontalAmount;
uv.y /= _VerticalAmount;
//纹理采样
fixed4 c = tex2D(_MainTex, uv);
c.rgb *= _Color;
return c;
}
ENDCG
}
}
//FallBack "Transparent/VertexLit"
}
效果：
滚动的背景
Shader "Unity Shaders Book/Chapter 11/Scrolling Background" {
Properties {
_MainTex ("Base Layer (RGB)", 2D) = "white" {}
_DetailTex ("2nd Layer (RGB)", 2D) = "white" {}
_ScrollX ("Base layer Scroll Speed", Float) = 1.0
_Scroll2X ("2nd layer Scroll Speed", Float) = 1.0
_Multiplier ("Layer Multiplier", Float) = 1
}
SubShader {
Tags { "RenderType"="Opaque" "Queue"="Geometry"}
Pass {
Tags { "LightMode"="ForwardBase" }
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
sampler2D _MainTex;
sampler2D _DetailTex;
float4 _MainTex_ST;
float4 _DetailTex_ST;
float _ScrollX;
float _Scroll2X;
float _Multiplier;
struct a2v {
float4 vertex : POSITION;
float4 texcoord : TEXCOORD0;
};
struct v2f {
float4 pos : SV_POSITION;
float4 uv : TEXCOORD0;
};
v2f vert (a2v v) {
v2f o;
//将顶点坐标从模型空间转换到裁剪空间
o.pos = mul(UNITY_MATRIX_MVP, v.vertex);
////将纹理坐标映射到顶点上以及zw偏移,并用ScrollX对x轴坐标进行偏移
o.uv.xy = TRANSFORM_TEX(v.texcoord, _MainTex) + frac(float2(_ScrollX, 0.0) * _Time.y);
o.uv.zw = TRANSFORM_TEX(v.texcoord, _DetailTex) + frac(float2(_Scroll2X, 0.0) * _Time.y);
return o;
}
fixed4 frag (v2f i) : SV_Target {
//纹理采样
fixed4 firstLayer = tex2D(_MainTex, i.uv.xy);
fixed4 secondLayer = tex2D(_DetailTex, i.uv.zw);
//纹理混合
fixed4 c = lerp(firstLayer, secondLayer, secondLayer.a);
c.rgb *= _Multiplier;
return c;
}
ENDCG
}
}
FallBack "VertexLit"
}
效果：
顶点动画
效果：
Shader "Unity Shaders Book/Chapter 11/Water" {
Properties {
_MainTex ("Main Tex", 2D) = "white" {}
_Color ("Color Tint", Color) = (1, 1, 1, 1)
_Magnitude ("Distortion Magnitude", Float) = 1
_Frequency ("Distortion Frequency", Float) = 1
_InvWaveLength ("Distortion Inverse Wave Length", Float) = 10
_Speed ("Speed", Float) = 0.5
}
SubShader {
// Need to disable batching because of the vertex animation
Tags {"Queue"="Transparent" "IgnoreProjector"="True" "RenderType"="Transparent" "DisableBatching"="True"}
Pass {
Tags { "LightMode"="ForwardBase" }
ZWrite Off
Blend SrcAlpha OneMinusSrcAlpha
Cull Off
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
sampler2D _MainTex;
float4 _MainTex_ST;
fixed4 _Color;
float _Magnitude;
float _Frequency;
float _InvWaveLength;
float _Speed;
struct a2v {
float4 vertex : POSITION;
float4 texcoord : TEXCOORD0;
};
struct v2f {
float4 pos : SV_POSITION;
float2 uv : TEXCOORD0;
};
v2f vert(a2v v) {
v2f o;
//顶点偏移量，只对x偏移
float4 offset;
offset.yzw = float3(0.0, 0.0, 0.0);
//Frequency控制频率f
//InvWaveLength控制波长L
//Magnitude控制幅度k
offset.x = sin(_Frequency * _Time.y + v.vertex.x * _InvWaveLength + v.vertex.y * _InvWaveLength + v.vertex.z * _InvWaveLength) * _Magnitude;
o.pos = mul(UNITY_MATRIX_MVP, v.vertex + offset);
//纹理采样
o.uv = TRANSFORM_TEX(v.texcoord, _MainTex);
//对v偏移，横向
o.uv += float2(0.0, _Time.y * _Speed);
return o;
}
fixed4 frag(v2f i) : SV_Target {
fixed4 c = tex2D(_MainTex, i.uv);
c.rgb *= _Color.rgb;
return c;
}
ENDCG
}
}
FallBack "Transparent/VertexLit"
}
效果：