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：