作为shader编写的一段练习题我将物体的平移、缩放和旋转分别利用shader实现，此处代码仅作为参考，尽量不要在shader代码中利用if语句判断。
效果如下：
shader代码如下：
Shader "Unlit/CustomChange"
{
Properties
{
//显示一个下拉菜单
[Enum(Translational,0,Scale,1,Rotation,2)]_Transform("Transform",float) = 0
_Translational("Translational",vector) = (0.0,0.0,0.0,0.0)
_Scale("Scale",vector) = (1.0,1.0,1.0,1.0)
_Rotation("Rotation",vector) = (0.0,0.0,0.0,1.0)
}
SubShader
{
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
uniform float _Transform;
uniform float4 _Translational;
uniform float4 _Scale;
uniform float4 _Rotation;
struct appdata
{
float4 vertex : POSITION;
};
struct v2f
{
float4 color:COLOR;
float4 vertex : SV_POSITION;
};
//平移矩阵
float4x4 Translational(float4 translational)
{
return float4x4(1.0, 0.0, 0.0, translational.x,
0.0, 1.0, 0.0, translational.y,
0.0, 0.0, 1.0, translational.z,
0.0, 0.0, 0.0, 1.0);
}
//缩放矩阵
float4x4 Scale(float4 scale)
{
return float4x4(scale.x, 0.0, 0.0, 0.0,
0.0, scale.y, 0.0, 0.0,
0.0, 0.0, scale.z, 0.0,
0.0, 0.0, 0.0, 1.0);
}
//旋转矩阵
float4x4 Rotation(float4 rotation)
{
float radX = radians(rotation.x);
float radY = radians(rotation.y);
float radZ = radians(rotation.z);
float sinX = sin(radX);
float cosX = cos(radX);
float sinY = sin(radY);
float cosY = cos(radY);
float sinZ = sin(radZ);
float cosZ = cos(radZ);
return float4x4(cosY*cosZ, -cosY * sinZ, sinY, 0.0,
cosX*sinZ + sinX * sinY*cosZ, cosX*cosZ - sinX * sinY*sinZ, -sinX * cosY, 0.0,
sinX*sinZ - cosX * sinY*cosZ, sinX*cosZ + cosX * sinY*sinZ, cosX*cosY, 0.0,
0.0, 0.0, 0.0, 1.0);
}
v2f vert (appdata v)
{
v2f o;
//在模型空间计算，坐标和矩阵相乘
if (_Transform == 0)
{
v.vertex = mul(Translational(_Translational), v.vertex);
}
else if (_Transform == 1)
{
v.vertex = mul(Scale(_Scale), v.vertex);
}
else
{
v.vertex = mul(Rotation(_Rotation), v.vertex);
}
o.vertex = UnityObjectToClipPos(v.vertex);//将坐标从模型空间转到裁切空间
o.color = float4(1, 0, 0, 1);
return o;
}
fixed4 frag (v2f i) : COLOR
{
return i.color;
}
ENDCG
}
}
}
详细内容解释可以看链接：Unity Shader中的平移、缩放、旋转
为了更加方便使用我将三种变换形式合在一起又重新写了一份，感兴趣的可以看一下，
效果如下：
shader代码如下：
Shader "Unlit/CustomChange(Blend)"
{
Properties
{
_Translational("Translational",vector) = (0.0,0.0,0.0,0.0)
_Scale("Scale",vector) = (1.0,1.0,1.0,1.0)
_Rotation("Rotation",vector) = (0.0,0.0,0.0,1.0)
}
SubShader
{
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
//uniform float _Transform;
uniform float4 _Translational;
uniform float4 _Scale;
uniform float4 _Rotation;
struct appdata
{
float4 vertex : POSITION;
};
struct v2f
{
float4 color:COLOR;
float4 vertex : SV_POSITION;
};
//平移矩阵
float4x4 Translational(float4 translational)
{
return float4x4(1.0, 0.0, 0.0, translational.x,
0.0, 1.0, 0.0, translational.y,
0.0, 0.0, 1.0, translational.z,
0.0, 0.0, 0.0, 1.0);
}
//缩放矩阵
float4x4 Scale(float4 scale)
{
return float4x4(scale.x, 0.0, 0.0, 0.0,
0.0, scale.y, 0.0, 0.0,
0.0, 0.0, scale.z, 0.0,
0.0, 0.0, 0.0, 1.0);
}
//旋转矩阵
float4x4 TRSBlend(float4 rotation)
{
float radX = radians(rotation.x);
float radY = radians(rotation.y);
float radZ = radians(rotation.z);
float sinX = sin(radX);
float cosX = cos(radX);
float sinY = sin(radY);
float cosY = cos(radY);
float sinZ = sin(radZ);
float cosZ = cos(radZ);
float4x4 r= float4x4(cosY*cosZ, -cosY * sinZ, sinY, 0.0,
cosX*sinZ + sinX * sinY*cosZ, cosX*cosZ - sinX * sinY*sinZ, -sinX * cosY, 0.0,
sinX*sinZ - cosX * sinY*cosZ, sinX*cosZ + cosX * sinY*sinZ, cosX*cosY, 0.0,
0.0, 0.0, 0.0, 1.0);
float4x4 tr = mul(Translational(_Translational), r);
return mul(tr, Scale(_Scale));
}
v2f vert(appdata v)
{
v2f o;
//在模型空间计算
v.vertex = mul(TRSBlend(_Rotation), v.vertex);
o.vertex = UnityObjectToClipPos(v.vertex);//将坐标从模型空间转到裁切空间
o.color = float4(1, 0, 0, 1);
return o;
}
fixed4 frag(v2f i) : COLOR
{
return i.color;
}
ENDCG
}
}
}