【游戏开发】摄像机遮挡半透
大多数游戏都加入了遮挡半透这个效果，即角色跟摄像机中间有物体遮挡时，会将这个物体半透，还会有渐隐和渐现的过程。
如下图：
实现过程如下图：
把脚本挂到摄像机上，并把需要半透的物体设置可半透的材质和半透层即可
具体代码如下，shader是最普通的diffuse加了半透所需代码段：
using System.Collections.Generic;
using UnityEngine;
public class OcclusionTransparent : MonoBehaviour
{
public GameObject targetObj;
public LayerMask OHLayer;
public float maxDistance = 10f;
[Range(0.1f, 5f)]
public float fadeTime = 2f;
[Range(0f, 1f)]
public float fadeDstAlpha = 0.3f;
private Camera mainCamera;
private Vector3 cameraPos;
private Vector3 targetPos;
private class TransObjAttr
{
public Material[] materials;
public float curfadeTime = 0f;
public bool transFlag = false;
}
Dictionary<Renderer, TransObjAttr> transObjDic = new Dictionary<Renderer, TransObjAttr>();
List<Renderer> transObjClearList = new List<Renderer>();
private void Start()
{
mainCamera = GetComponent<Camera>();
if (mainCamera == null || targetObj == null)
{
enabled = false;
return;
}
else
{
cameraPos = mainCamera.transform.position;
targetPos = targetObj.transform.position;
}
}
private void Update()
{
cameraPos = mainCamera.transform.position;
targetPos = targetObj.transform.position;
Debug.DrawLine(cameraPos, targetPos, Color.red);
FadeOutTransObj();
if (Physics.Raycast(targetPos, (cameraPos - targetPos).normalized, out RaycastHit hitInfo, maxDistance, OHLayer))
UpdataTransObjDic(hitInfo);
FadeInTransObj();
}
/// Shader "Scene/Diffuse"
{
Properties
{
_MainTex ("Texture", 2D) = "white" {
}
_Color ("Base Color", Color) = (1,1,1,1)
[HideInInspector] _Alpha ("", float) = 1
[HideInInspector] _SrcBlend ("", int) = 1
[HideInInspector] _DstBlend ("", int) = 0
}
SubShader
{
Tags {
"Queue"="Geometry" "RenderType"="Opaque" }
LOD 200
Pass
{
Blend [_SrcBlend][_DstBlend]
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
#include "Lighting.cginc"
struct appdata
{
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
float3 normal : NORMAL;
};
struct v2f
{
float4 vertex : SV_POSITION;
float2 uv : TEXCOORD0;
float3 worldPos : TEXCOORD1;
float3 worldNormal : TEXCOORD2;
};
sampler2D _MainTex;
float4 _MainTex_ST;
half4 _Color;
half _Alpha;
v2f vert (appdata v)
{
v2f o;
o.vertex = UnityObjectToClipPos(v.vertex);
o.uv = TRANSFORM_TEX(v.uv, _MainTex);
o.worldPos = mul(unity_ObjectToWorld, v.vertex.xyz);
o.worldNormal = UnityObjectToWorldNormal(v.normal);
return o;
}
fixed4 frag (v2f i) : SV_Target
{
half4 texColor = tex2D(_MainTex, i.uv);
half3 normal = normalize(i.worldNormal);
half3 lightDir = normalize(UnityWorldSpaceLightDir(i.worldPos));
half diff = dot(normal, lightDir) * 0.5 + 0.5;
half3 diffColor = _LightColor0.rgb * _Color.rgb * texColor.rgb * diff;
return half4(diffColor, texColor.a * _Alpha);
}
ENDCG
}
}
}