在Forward管線中，如果後期需要用到法線貼圖，
需要將相機depthTextureMode 的Flag設置爲DepthNormals
在相機面板可以確認
這樣的話會把物體走一遍"Hidden/Internal-DepthNormalsTexture"來渲染出一張屏幕的Normal和Depth
"Hidden/Internal-DepthNormalsTexture"有很多pass，第一個是畫不透明，第二個是畫AlphaTest物體
畫AlphaTest物體會需要傳入_MainTex來確認alpha，還有_Cutoff參數，並且RenderType需要爲"RenderType"="TransparentCutout"，不滿足上面兩個條件就會走不透明的pass，這樣被clip的部分也會畫到法線圖片上，就會出錯
看下面的代碼可以知道，pass分成了不透明，AlphaTest，還有地形相關的pass，clip是在fragment shader中做的，所以需要這些參數
Unity.cginc中
#define DECODE_EYEDEPTH(i) LinearEyeDepth(i)
#define COMPUTE_EYEDEPTH(o) o = -UnityObjectToViewPos( v.vertex ).z
#define COMPUTE_DEPTH_01 -(UnityObjectToViewPos( v.vertex ).z * _ProjectionParams.w)
#define COMPUTE_VIEW_NORMAL normalize(mul((float3x3)UNITY_MATRIX_IT_MV, v.normal))
輸出法線原理是vertex shader中將頂點法線由模型空間變爲世界空間，再在fragment shader中輸出
輸出深度的原理是將Z(相機空間深度)*w(1/farPlane)得出歸一化深度
但是有一個疑問這兩個的shader參數是怎麼同步的呢？
Shader "Hidden/Internal-DepthNormalsTexture" {
Properties {
_MainTex ("", 2D) = "white" {}
_Cutoff ("", Float) = 0.5
_Color ("", Color) = (1,1,1,1)
}
SubShader {
Tags { "RenderType"="Opaque" }
Pass {
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
struct v2f {
float4 pos : SV_POSITION;
float4 nz : TEXCOORD0;
UNITY_VERTEX_OUTPUT_STEREO
};
v2f vert( appdata_base v ) {
v2f o;
UNITY_SETUP_INSTANCE_ID(v);
UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(o);
o.pos = UnityObjectToClipPos(v.vertex);
o.nz.xyz = COMPUTE_VIEW_NORMAL;
o.nz.w = COMPUTE_DEPTH_01;
return o;
}
fixed4 frag(v2f i) : SV_Target {
return EncodeDepthNormal (i.nz.w, i.nz.xyz);
}
ENDCG
}
}
SubShader {
Tags { "RenderType"="TransparentCutout" }
Pass {
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
struct v2f {
float4 pos : SV_POSITION;
float2 uv : TEXCOORD0;
float4 nz : TEXCOORD1;
UNITY_VERTEX_OUTPUT_STEREO
};
uniform float4 _MainTex_ST;
v2f vert( appdata_base v ) {
v2f o;
UNITY_SETUP_INSTANCE_ID(v);
UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(o);
o.pos = UnityObjectToClipPos(v.vertex);
o.uv = TRANSFORM_TEX(v.texcoord, _MainTex);
o.nz.xyz = COMPUTE_VIEW_NORMAL;
o.nz.w = COMPUTE_DEPTH_01;
return o;
}
uniform sampler2D _MainTex;
uniform fixed _Cutoff;
uniform fixed4 _Color;
fixed4 frag(v2f i) : SV_Target {
fixed4 texcol = tex2D( _MainTex, i.uv );
clip( texcol.a*_Color.a - _Cutoff );
return EncodeDepthNormal (i.nz.w, i.nz.xyz);
}
ENDCG
}
}
SubShader {
Tags { "RenderType"="TreeBark" }
Pass {
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
#include "Lighting.cginc"
#include "UnityBuiltin3xTreeLibrary.cginc"
struct v2f {
float4 pos : SV_POSITION;
float2 uv : TEXCOORD0;
float4 nz : TEXCOORD1;
UNITY_VERTEX_OUTPUT_STEREO
};
v2f vert( appdata_full v ) {
v2f o;
UNITY_SETUP_INSTANCE_ID(v);
UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(o);
TreeVertBark(v);
o.pos = UnityObjectToClipPos(v.vertex);
o.uv = v.texcoord.xy;
o.nz.xyz = COMPUTE_VIEW_NORMAL;
o.nz.w = COMPUTE_DEPTH_01;
return o;
}
fixed4 frag( v2f i ) : SV_Target {
return EncodeDepthNormal (i.nz.w, i.nz.xyz);
}
ENDCG
}
}
SubShader {
Tags { "RenderType"="TreeLeaf" }
Pass {
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
#include "Lighting.cginc"
#include "UnityBuiltin3xTreeLibrary.cginc"
struct v2f {
float4 pos : SV_POSITION;
float2 uv : TEXCOORD0;
float4 nz : TEXCOORD1;
UNITY_VERTEX_OUTPUT_STEREO
};
v2f vert( appdata_full v ) {
v2f o;
UNITY_SETUP_INSTANCE_ID(v);
UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(o);
TreeVertLeaf(v);
o.pos = UnityObjectToClipPos(v.vertex);
o.uv = v.texcoord.xy;
o.nz.xyz = COMPUTE_VIEW_NORMAL;
o.nz.w = COMPUTE_DEPTH_01;
return o;
}
uniform sampler2D _MainTex;
uniform fixed _Cutoff;
fixed4 frag( v2f i ) : SV_Target {
half alpha = tex2D(_MainTex, i.uv).a;
clip (alpha - _Cutoff);
return EncodeDepthNormal (i.nz.w, i.nz.xyz);
}
ENDCG
}
}
SubShader {
Tags { "RenderType"="TreeOpaque" "DisableBatching"="True" }
Pass {
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
#include "TerrainEngine.cginc"
struct v2f {
float4 pos : SV_POSITION;
float4 nz : TEXCOORD0;
UNITY_VERTEX_OUTPUT_STEREO
};
struct appdata {
float4 vertex : POSITION;
float3 normal : NORMAL;
fixed4 color : COLOR;
UNITY_VERTEX_INPUT_INSTANCE_ID
};
v2f vert( appdata v ) {
v2f o;
UNITY_SETUP_INSTANCE_ID(v);
UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(o);
TerrainAnimateTree(v.vertex, v.color.w);
o.pos = UnityObjectToClipPos(v.vertex);
o.nz.xyz = COMPUTE_VIEW_NORMAL;
o.nz.w = COMPUTE_DEPTH_01;
return o;
}
fixed4 frag(v2f i) : SV_Target {
return EncodeDepthNormal (i.nz.w, i.nz.xyz);
}
ENDCG
}
}
SubShader {
Tags { "RenderType"="TreeTransparentCutout" "DisableBatching"="True" }
Pass {
Cull Back
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
#include "TerrainEngine.cginc"
struct v2f {
float4 pos : SV_POSITION;
float2 uv : TEXCOORD0;
float4 nz : TEXCOORD1;
UNITY_VERTEX_OUTPUT_STEREO
};
struct appdata {
float4 vertex : POSITION;
float3 normal : NORMAL;
fixed4 color : COLOR;
float4 texcoord : TEXCOORD0;
UNITY_VERTEX_INPUT_INSTANCE_ID
};
v2f vert( appdata v ) {
v2f o;
UNITY_SETUP_INSTANCE_ID(v);
UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(o);
TerrainAnimateTree(v.vertex, v.color.w);
o.pos = UnityObjectToClipPos(v.vertex);
o.uv = v.texcoord.xy;
o.nz.xyz = COMPUTE_VIEW_NORMAL;
o.nz.w = COMPUTE_DEPTH_01;
return o;
}
uniform sampler2D _MainTex;
uniform fixed _Cutoff;
fixed4 frag(v2f i) : SV_Target {
half alpha = tex2D(_MainTex, i.uv).a;
clip (alpha - _Cutoff);
return EncodeDepthNormal (i.nz.w, i.nz.xyz);
}
ENDCG
}
Pass {
Cull Front
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
#include "TerrainEngine.cginc"
struct v2f {
float4 pos : SV_POSITION;
float2 uv : TEXCOORD0;
float4 nz : TEXCOORD1;
UNITY_VERTEX_OUTPUT_STEREO
};
struct appdata {
float4 vertex : POSITION;
float3 normal : NORMAL;
fixed4 color : COLOR;
float4 texcoord : TEXCOORD0;
UNITY_VERTEX_INPUT_INSTANCE_ID
};
v2f vert( appdata v ) {
v2f o;
UNITY_SETUP_INSTANCE_ID(v);
UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(o);
TerrainAnimateTree(v.vertex, v.color.w);
o.pos = UnityObjectToClipPos(v.vertex);
o.uv = v.texcoord.xy;
o.nz.xyz = -COMPUTE_VIEW_NORMAL;
o.nz.w = COMPUTE_DEPTH_01;
return o;
}
uniform sampler2D _MainTex;
uniform fixed _Cutoff;
fixed4 frag(v2f i) : SV_Target {
fixed4 texcol = tex2D( _MainTex, i.uv );
clip( texcol.a - _Cutoff );
return EncodeDepthNormal (i.nz.w, i.nz.xyz);
}
ENDCG
}
}
SubShader {
Tags { "RenderType"="TreeBillboard" }
Pass {
Cull Off
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
#include "TerrainEngine.cginc"
struct v2f {
float4 pos : SV_POSITION;
float2 uv : TEXCOORD0;
float4 nz : TEXCOORD1;
UNITY_VERTEX_OUTPUT_STEREO
};
v2f vert (appdata_tree_billboard v) {
v2f o;
UNITY_SETUP_INSTANCE_ID(v);
UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(o);
TerrainBillboardTree(v.vertex, v.texcoord1.xy, v.texcoord.y);
o.pos = UnityObjectToClipPos(v.vertex);
o.uv.x = v.texcoord.x;
o.uv.y = v.texcoord.y > 0;
o.nz.xyz = float3(0,0,1);
o.nz.w = COMPUTE_DEPTH_01;
return o;
}
uniform sampler2D _MainTex;
fixed4 frag(v2f i) : SV_Target {
fixed4 texcol = tex2D( _MainTex, i.uv );
clip( texcol.a - 0.001 );
return EncodeDepthNormal (i.nz.w, i.nz.xyz);
}
ENDCG
}
}
SubShader {
Tags { "RenderType"="GrassBillboard" }
Pass {
Cull Off
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
#include "TerrainEngine.cginc"
struct v2f {
float4 pos : SV_POSITION;
fixed4 color : COLOR;
float2 uv : TEXCOORD0;
float4 nz : TEXCOORD1;
UNITY_VERTEX_OUTPUT_STEREO
};
v2f vert (appdata_full v) {
v2f o;
UNITY_SETUP_INSTANCE_ID(v);
UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(o);
WavingGrassBillboardVert (v);
o.color = v.color;
o.pos = UnityObjectToClipPos(v.vertex);
o.uv = v.texcoord.xy;
o.nz.xyz = COMPUTE_VIEW_NORMAL;
o.nz.w = COMPUTE_DEPTH_01;
return o;
}
uniform sampler2D _MainTex;
uniform fixed _Cutoff;
fixed4 frag(v2f i) : SV_Target {
fixed4 texcol = tex2D( _MainTex, i.uv );
fixed alpha = texcol.a * i.color.a;
clip( alpha - _Cutoff );
return EncodeDepthNormal (i.nz.w, i.nz.xyz);
}
ENDCG
}
}
SubShader {
Tags { "RenderType"="Grass" }
Pass {
Cull Off
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
#include "TerrainEngine.cginc"
struct v2f {
float4 pos : SV_POSITION;
fixed4 color : COLOR;
float2 uv : TEXCOORD0;
float4 nz : TEXCOORD1;
UNITY_VERTEX_OUTPUT_STEREO
};
v2f vert (appdata_full v) {
v2f o;
UNITY_SETUP_INSTANCE_ID(v);
UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(o);
WavingGrassVert (v);
o.color = v.color;
o.pos = UnityObjectToClipPos(v.vertex);
o.uv = v.texcoord;
o.nz.xyz = COMPUTE_VIEW_NORMAL;
o.nz.w = COMPUTE_DEPTH_01;
return o;
}
uniform sampler2D _MainTex;
uniform fixed _Cutoff;
fixed4 frag(v2f i) : SV_Target {
fixed4 texcol = tex2D( _MainTex, i.uv );
fixed alpha = texcol.a * i.color.a;
clip( alpha - _Cutoff );
return EncodeDepthNormal (i.nz.w, i.nz.xyz);
}
ENDCG
}
}
Fallback Off
}
------by wolf96 2018/12/20