Unity--使用shader给角色描边异常
unity版本:Unity 2018.2.0f2 (64-bit)
shader实现如下:
// Upgrade NOTE: replaced 'mul(UNITY_MATRIX_MVP,*)' with 'UnityObjectToClipPos(*)'
#pragma fragmentoption ARB_precision_hint_fastest
#include "UnityCG.cginc"
half _Outline;
fixed4 _OutlineColor;
struct appdata {
half4 vertex : POSITION;
half3 normal : NORMAL;
};
struct v2f_outline {
half4 pos : SV_POSITION;
};
v2f_outline vert_outline(appdata v) {
v2f_outline o;
o.pos = UnityObjectToClipPos(v.vertex);
half3 norm = mul ((float3x3)UNITY_MATRIX_IT_MV, v.normal);
half2 offset = TransformViewToProjection(norm.xy);
o.pos.xy += offset * o.pos.z * _Outline;
return o;
}
fixed4 frag_outline(v2f_outline i) : COLOR
{
return _OutlineColor;
}
ios真机上描边显示正常,android真机上描边显示得很粗,(项目保密,截图不便公开,找了个图替代)
左边是预期的情况,右边是android真机上显示出来的效果
造成这个问题的原因是代码中用到o.pos.z,这个值在不同平台上的值的范围不同,即
o.pos.xy += offset * o.pos.z * _Outline;
官方的解释(https://docs.unity3d.com/Manual/SL-PlatformDifferences.html )
github上找到解决方案(https://github.com/Shrimpey/Outlined-Diffuse-Shader-Fixed )
最终的实现如下
// Upgrade NOTE: replaced 'mul(UNITY_MATRIX_MVP,*)' with 'UnityObjectToClipPos(*)'
#pragma fragmentoption ARB_precision_hint_fastest
#include "UnityCG.cginc"
half _Outline;
fixed4 _OutlineColor;
struct appdata {
half4 vertex : POSITION;
half3 normal : NORMAL;
};
struct v2f_outline {
half4 pos : SV_POSITION;
};
v2f_outline vert_outline(appdata v) {
v2f_outline o;
v.vertex *= (1 + _Outline);
o.pos = UnityObjectToClipPos(v.vertex);
return o;
}
fixed4 frag_outline(v2f_outline i) : COLOR
{
return _OutlineColor;
}