Projector的一些参数设置

Posted 2023-03-29 就当笔记吧

有点类似手电筒原理，手电筒照到的表面有一圈变亮，而Projector的话就是投射到的地方形成一个阴影。

 

透视模式

 

透视模式去掉衰减（越远阴影越淡）

 

透视模式离投射表面越近，阴影就越小

 

正交模式，离投射平面的距离不管远近，阴影都是一样大小

 

调整宽高比，可以让阴影变成椭圆形

 

Projector用到的shader和图片来自于Unity的standard assets

Shader "Projector/Multiply" 
    Properties 
        _ShadowTex ("Cookie", 2D) = "gray" 
        _FalloffTex ("FallOff", 2D) = "white" 
    
    Subshader 
        Tags "Queue"="Transparent"
        Pass 
            ZWrite Off
            ColorMask RGB
            Blend DstColor Zero
            Offset -1, -1

            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #pragma multi_compile_fog
            #include "UnityCG.cginc"
            
            struct v2f 
                float4 uvShadow : TEXCOORD0;
                float4 uvFalloff : TEXCOORD1;
                UNITY_FOG_COORDS(2)
                float4 pos : SV_POSITION;
            ;
            
            float4x4 unity_Projector;
            float4x4 unity_ProjectorClip;
            
            v2f vert (float4 vertex : POSITION)
            
                v2f o;
                o.pos = UnityObjectToClipPos(vertex);
                o.uvShadow = mul (unity_Projector, vertex);
                o.uvFalloff = mul (unity_ProjectorClip, vertex);
                UNITY_TRANSFER_FOG(o,o.pos);
                return o;
            
            
            sampler2D _ShadowTex;
            sampler2D _FalloffTex;
            
            fixed4 frag (v2f i) : SV_Target
            
                fixed4 texS = tex2Dproj (_ShadowTex, UNITY_PROJ_COORD(i.uvShadow));
                texS.a = 1.0-texS.a;

                fixed4 texF = tex2Dproj (_FalloffTex, UNITY_PROJ_COORD(i.uvFalloff));
                fixed4 res = lerp(fixed4(1,1,1,0), texS, texF.a);

                UNITY_APPLY_FOG_COLOR(i.fogCoord, res, fixed4(1,1,1,1));
                return res;
            
            ENDCG
        
    

falloff

 

shadow