人物影子制作

在人物对象的下面创建一个空物体，命名为PlayerShadow，在其下建一个Camera，如下设置：

在playerShadow添加三个脚本

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class CharShadowScript : MonoBehaviour {

public Transform display;
private GameObject ShadowCamera;
GameObject map;

RenderTexture mTex = null;
private void Start()
{
map = transform.GetChild(1).gameObject;
ShadowCamera = transform.GetChild(0).gameObject;
if (!display)
display = transform.parent;
mTex = new RenderTexture(128, 128, 0);
mTex.name = "PlayerShadow" + GetInstanceID();
Camera mCamera = ShadowCamera.GetComponent<Camera>();
mCamera.targetTexture = mTex;
}
private void Update()
{
if(display != null)
{
map.GetComponent<Renderer>().material.mainTexture = mTex;
}
}
}

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class KeepStartPositionOffset : MonoBehaviour {

public Transform targetObject;
Vector3 positionOffset = new Vector3();

private void Start()
{
if(!targetObject)
{
targetObject = transform.parent;
}
if(targetObject)
{
positionOffset = transform.position - targetObject.position;
}
}
private void Update()
{
if(targetObject)
{
transform.position = targetObject.position + positionOffset;
}
}
}

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class FollowCameraFoward : MonoBehaviour {

public Transform cameraTransform;
Quaternion initRotation;

private void Start()
{
if(cameraTransform == null)
{
cameraTransform = GameObject.Find("MainCamTarget").transform;
}
initRotation = transform.rotation;
}
private void FixedUpdate()
{
if(cameraTransform == null)
{
cameraTransform = GameObject.Find("MainCamTarget").transform;
}
transform.rotation = Quaternion.RotateTowards(cameraTransform.rotation, initRotation, Mathf.Infinity);
}
}

创建一个RenderTexture命名为playerShadow，创建一个Material和一个Shader，shader代码：

Shader "MyShader/PlayerShadow"
{
Properties
{
_Color("Main Color",Color) = (1,1,1,1)
_MainTex("Base (RGB) Alpha(A)", 2D) = "white" {}
_Cutoff("Base Alpha cutoff",Range(0,.1)) = .02
_SpcTex("Base (RGB) Alpha (A)",2D) = "white"{}
}
SubShader
{
Tags{"Queue" = "Transparent" "IgnoreProjector" = "True" "RanderType" = "TransparentCutout"}
Lighting off
ZWrite off
Cull off
Blend SrcAlpha OneMinusSrcAlpha
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag

#include "UnityCG.cginc"

struct appdata_t
{
float4 vertex : POSITION;
float4 color : COLOR;
float2 texcoord : TEXCOORD0;
float2 texcoord1 : TEXCOORD1;
};
struct v2f
{
float4 vertex : SV_POSITION;
float4 color : COLOR;
float2 texcoord : TEXCOORD0;
float2 texcoord1 : TEXCOORD1;
};
sampler2D _MainTex;
sampler2D _SpecTex;
float4 _MainTex_ST;
float _Cutoff;

v2f vert(appdata_t v)
{
v2f o;
o.vertex = UnityObjectToClipPos(v.vertex);
o.color = v.color;
o.texcoord = TRANSFORM_TEX(v.texcoord, _MainTex);

return o;
}
float4 _Color;
half4 frag(v2f i) : SV_Target
{
half4 col = tex2D(_MainTex,i.texcoord);
half4 col1 = tex2D(_SpecTex, i.texcoord);

if (col.a < _Cutoff)
{
clip(col.a - _Cutoff);
}
else
{
col.rgb = col.rgb * float3(0, 0, 0);
col.rgb = col.rgb + _Color;
col.a = _Color.a;
}
return col;
}
ENDCG
}
}
}

将这个RenderTexture赋给刚创建的Camera的TargetTexture，大功告成

效果图：