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由 https://www.jianshu.com/p/9d93383fae0e 进行优化
先上优化前的代码
Shader "Custom/NewShader" {
Properties {
_MainTex ("Base (RGB)", 2D) = "white" {}
//*********************绘制阴影的参数****************************
_ShadowPlane ("Shadow Plane", Vector) = (0,1,0,0.02)
_ShadowColor("Shadow Color",Color) = (0.2, 0.2, 0.2, 1)
_ShadowPara("Shadow Param",Vector) = (-0.006,60,3,0.02)
_lightDirection("LightDir",Vector) = (0,-1,0)
//*************************************************
}
SubShader {
Tags { "RenderType"="Opaque" }
LOD 200
CGPROGRAM
#pragma surface surf Lambert
sampler2D _MainTex;
struct Input {
float2 uv_MainTex;
};
void surf (Input IN, inout SurfaceOutput o) {
half4 c = tex2D (_MainTex, IN.uv_MainTex);
o.Albedo = c.rgb;
o.Alpha = c.a;
}
ENDCG
//*******************绘制阴影的参数pass 只需要在你原来的shader里面加入这个pass就可以绘制出实时阴影了******************************
pass{
Tags { "QUEUE"="Transparent" "RenderType"="Transparent" }
ZWrite Off
Fog { Mode Off }
Blend SrcAlpha OneMinusSrcAlpha
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
struct v2f {
float4 pos : SV_POSITION;
half3 texcord0 : TEXCOORD0;
half3 texcord1 : TEXCOORD1;
};
uniform fixed4 _ShadowPlane;
uniform fixed4 _ShadowPara;
uniform fixed3 _lightDirection;
uniform fixed4 _ShadowColor;
v2f vert(appdata_tan v)
{
v2f o;
fixed3 vt;
vt = mul(_Object2World , v.vertex).xyz;
fixed3 tmpvar_3;
tmpvar_3 = (vt - (( (dot (_ShadowPlane.xyz, vt) - _ShadowPlane.w) / dot (_ShadowPlane.xyz, _lightDirection)) * _lightDirection));
fixed4 tmpvar_4;
tmpvar_4.w = 1.0;
tmpvar_4.xyz = tmpvar_3;
o.pos = mul(UNITY_MATRIX_VP , tmpvar_4);
o.texcord0 = mul(_Object2World,float4(0, 0, 0, 1));
o.texcord1 = tmpvar_3;
return o;
}
float4 frag(v2f inData) : COLOR
{
fixed3 posToPlane = inData.texcord0-inData.texcord1;
fixed4 f = _ShadowColor;
fixed v = pow (1.0 - clamp ((( sqrt( dot(posToPlane,posToPlane) ) * _ShadowPara.w) - _ShadowPara.x),0,1),_ShadowPara.y) * _ShadowPara.z;
f.w = v * _ShadowColor.a;
return f;
}
ENDCG
}
//*************************************************
}
FallBack "Diffuse"
}
使用后发现阴影会一直在一个平面上，角色如果向上移动，阴影并不会跟着移动。所以需要实时获取角色的高度距离。
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
[ExecuteInEditMode]
public class ActorPosition : MonoBehaviour{
void Update(){
Shader.GetGlobalVector("_Position",transform.position);
}
}
将该脚本挂到角色身上，获取角色的坐标，同时 shader 中定义 “_Position” 接收角色的坐标值
uniform fixed3 _Position;
tmpvar_3 = (vt - (( (dot (_ShadowPlane.xyz, vt) - _Position.y) / dot (_ShadowPlane.xyz, _lightDirection)) * _lightDirection));
改后的shader
Shader "Custom/NewShader" {
Properties {
_MainTex ("Base (RGB)", 2D) = "white" {}
//*********************绘制阴影的参数****************************
_ShadowPlane ("阴影的平面", Vector) = (0,1,0,0.02)
_ShadowColor("阴影颜色",Color) = (0.2, 0.2, 0.2, 1)
_ShadowPara("阴影范围",Vector) = (-0.006,60,3,0.02)
_lightDirection("灯光方向",Vector) = (0,-1,0)
//*************************************************
}
SubShader {
Tags { "RenderType"="Opaque" }
LOD 200
CGPROGRAM
#pragma surface surf Lambert
sampler2D _MainTex;
struct Input {
float2 uv_MainTex;
};
void surf (Input IN, inout SurfaceOutput o) {
half4 c = tex2D (_MainTex, IN.uv_MainTex);
o.Albedo = c.rgb;
o.Alpha = c.a;
}
ENDCG
//*******************绘制阴影的参数pass 只需要在你原来的shader里面加入这个pass就可以绘制出实时阴影了******************************
pass{
Tags { "QUEUE"="Transparent" "RenderType"="Transparent" }
ZWrite Off
Fog { Mode Off }
Blend SrcAlpha OneMinusSrcAlpha
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
struct v2f {
float4 pos : SV_POSITION;
half3 texcord0 : TEXCOORD0;
half3 texcord1 : TEXCOORD1;
};
fixed3 _ShadowPlane;
fixed4 _ShadowPara;
fixed3 _lightDirection;
fixed4 _ShadowColor;
fixed3 _Position;
v2f vert(appdata_tan v)
{
v2f o;
fixed3 vt;
vt = mul(_Object2World , v.vertex).xyz;
fixed3 tmpvar_3;
tmpvar_3 = (vt - (( (dot (_ShadowPlane.xyz, vt) - _Position.y) / dot (_ShadowPlane.xyz, _lightDirection)) * _lightDirection));
fixed4 tmpvar_4;
tmpvar_4.w = 1.0;
tmpvar_4.xyz = tmpvar_3;
o.pos = mul(UNITY_MATRIX_VP , tmpvar_4);
o.texcord0 = mul(_Object2World,float4(0, 0, 0, 1));
o.texcord1 = tmpvar_3;
return o;
}
float4 frag(v2f inData) : SV_TARGET
{
fixed3 posToPlane = inData.texcord0-inData.texcord1;
fixed4 f = _ShadowColor;
fixed v = pow (1.0 - clamp ((( sqrt( dot(posToPlane,posToPlane) ) * _ShadowPara.w) - _ShadowPara.x),0,1),_ShadowPara.y) * _ShadowPara.z;
f.w = v * _ShadowColor.a;
return f;
}
ENDCG
}
//*************************************************
}
//FallBack "Diffuse"
}