Unity in standard PBR (i)

Focus on the Forwardbase

Standard.shader

#pragma vertex vertbase#pragma fragment fragbase"  Unitystandardcoreforward.cginc"

Track to Unitystandardcoreforward.cginc

#ifUnity_standard_simple#include"Unitystandardcoreforwardsimple.cginc"vertexoutputbasesimple vertbase (Vertexinput v) {returnVertforwardbasesimple (v);} Vertexoutputforwardaddsimple Vertadd (Vertexinput v) {returnVertforwardaddsimple (v);} Half4 fragbase (vertexoutputbasesimple i): sv_target {returnfragforwardbasesimpleinternal (i);} Half4 Fragadd (vertexoutputforwardaddsimple i): sv_target {returnfragforwardaddsimpleinternal (i);}#else#include"Unitystandardcore.cginc"vertexoutputforwardbase vertbase (Vertexinput v) {returnVertforwardbase (v);} Vertexoutputforwardadd Vertadd (Vertexinput v) {returnVertforwardadd (v);} Half4 fragbase (vertexoutputforwardbase i): sv_target {returnfragforwardbaseinternal (i);} Half4 Fragadd (Vertexoutputforwardadd i): sv_target {returnfragforwardaddinternal (i);}#endif

Unity_standard_simple switch is a simplified version of the meaning, into the bottom of the branch

Vertex shader Vertforwardbase

First look at the output

structvertexoutputforwardbase{float4 pos:sv_position;    FLOAT4 tex:texcoord0;    Half3 Eyevec:texcoord1; Half4 tangenttoworldandparallax[3]: TEXCOORD2;//[3x3:tangenttoworld | 1x3:viewdirforparallax]Half4 Ambientorlightmapuv:texcoord5;//SH or Lightmap UVShadow_coords (6) Unity_fog_coords (7)    //next ones would not fit to SM2.0 limits, but they is always for sm3.0+    #ifUnity_require_frag_worldposFLOAT3 Posworld:texcoord8; #endif    #ifUnity_optimize_texcubelod#ifUnity_require_frag_worldposHalf3 refluvw:texcoord9; #elseHalf3 Refluvw:texcoord8; #endif    #endifUnity_vertex_output_stereo};

Unity_require_frag_worldpos want to Worldpos, want to

REFLUVW is used to make reflections, to
Unity_vertex_output_stereo is used for instantiation, do not
Simplified into

struct vertexoutputforwardbase{    float4 pos                          : sv_position;    FLOAT4 Tex                          : TEXCOORD0;    Half3 Eyevec                        : TEXCOORD1;    Half4 tangenttoworldandparallax[3]  : TEXCOORD2;    // [3x3:tangenttoworld | 1x3:viewdirforparallax]    Half4 ambientorlightmapuv           : TEXCOORD5;    // SH or Lightmap UV    Shadow_coords (6)    unity_fog_coords (7)    float3 posworld                     : TEXCOORD8;    Half3 REFLUVW                       : TEXCOORD9;};

And look at the vertex shader.

vertexoutputforwardbase vertforwardbase (Vertexinput v) {vertexoutputforwardbase o;    unity_setup_instance_id (v);    Unity_initialize_output (Vertexoutputforwardbase, O);    Unity_initialize_vertex_output_stereo (o); FLOAT4 Posworld=Mul (Unity_objecttoworld, V.vertex); #ifUnity_require_frag_worldposO.posworld=posworld.xyz; #endifO.pos=Unityobjecttoclippos (V.vertex); O.tex=Texcoords (v); O.eyevec= Normalizepervertexnormal (POSWORLD.XYZ-_worldspacecamerapos); FLOAT3 Normalworld=Unityobjecttoworldnormal (V.normal); #ifdef _tangent_to_world float4 Tangentworld=float4 (Unityobjecttoworlddir (V.TANGENT.XYZ), V.TANGENT.W); float3x3 Tangenttoworld=Createtangenttoworldpervertex (Normalworld, tangentworld.xyz, TANGENTWORLD.W); o.tangenttoworldandparallax[0].XYZ = tangenttoworld[0]; o.tangenttoworldandparallax[1].XYZ = tangenttoworld[1]; o.tangenttoworldandparallax[2].XYZ = tangenttoworld[2]; #elseo.tangenttoworldandparallax[0].XYZ =0; o.tangenttoworldandparallax[1].XYZ =0; o.tangenttoworldandparallax[2].XYZ =Normalworld; #endif    //We need this for shadow recevingTransfer_shadow (o); O.ambientorlightmapuv=Vertexgiforward (V, Posworld, Normalworld);        #ifdef _parallaxmap tangent_space_rotation; Half3 Viewdirforparallax=mul (Rotation, Objspaceviewdir (V.vertex)); o.tangenttoworldandparallax[0].W =viewdirforparallax.x; o.tangenttoworldandparallax[1].W =viewdirforparallax.y; o.tangenttoworldandparallax[2].W =viewdirforparallax.z; #endif    #ifUnity_optimize_texcubelodO.REFLUVW=reflect (O.eyevec, normalworld); #endifUnity_transfer_fog (O,o.pos); returno;}

UNITY_SETUP_INSTANCE_ID is for INSTANCE, don't

Unity_initialize_output didn't do anything.

Unity_initialize_vertex_output_stereo Don't

Normalizepervertexnormal is equal to nothing.

_tangent_to_world is a tangent space and a World Space transformation matrix Reservation

O.AMBIENTORLIGHTMAPUV = Vertexgiforward (V, Posworld, Normalworld);
Because of the intention to use PBR to do the role, no lightmap, so here equals

O.AMBIENTORLIGHTMAPUV = 0;

_parallaxmap Parallax Map, no

After removing the branch code as follows

Vertexoutputforwardbase Vertforwardbase (Vertexinput v) {    vertexoutputforwardbase o;    FLOAT4 Posworld = Mul (Unity_objecttoworld, V.vertex);    O.posworld = posworld.xyz;    O.pos = Unityobjecttoclippos (V.vertex);    O.tex = Texcoords (v);    O.eyevec = Normalizepervertexnormal (POSWORLD.XYZ-_worldspacecamerapos);    FLOAT3 Normalworld = Unityobjecttoworldnormal (v.normal); Float4 Tangentworld = Float4 (Unityobjecttoworlddir ( V.TANGENT.XYZ), V.TANGENT.W); float3x3 Tangenttoworld = Createtangenttoworldpervertex (NormalWorld, TANGENTWORLD.XYZ, TANGENTWORLD.W); o.tangenttoworldandparallax[0].xyz = TANGENTTOWORLD[0];O.TANGENTTOWORLDANDPARALLAX[1].XYZ = TANGENTTOWORLD[1];O.TANGENTTOWORLDANDPARALLAX[2].XYZ = tangenttoworld[2];    We need this for shadow receving    Transfer_shadow (o);    O.ambientorlightmapuv = 0;O.REFLUVW       = Reflect (O.eyevec, normalworld);    Unity_transfer_fog (O,o.pos);    return o;}

Now that the vertex shader is finished, the next pixel shader

Unity in standard PBR (i)