Learning notes--simple implementation of basic illumination model

Lambert illumination model, the illumination intensity is determined according to the angle of illumination vector and vertex discovery:

Shader"JAMES/VP Shader/lightmodel-lambert"{Properties {_maintex ("Maintex", 2D) =" White"{}} subshader {Pass {Tags {"Lightmode"="Forwardbase"} cgprogram#pragmaVertex vert#pragmaFragment Frag#include"Unitycg.cginc"                        float_lightcolor0;            Sampler2d _maintex;            FLOAT4 _maintex_st; structv2f {float4 pos:sv_position;                FLOAT2 uv:texcoord0;                FLOAT3 Lightdir:texcoord1;            FLOAT3 Normal:texcoord2;                        };                v2f Vert (Appdata_full v) {v2f o; O.pos=Mul (UNITY_MATRIX_MVP, V.vertex); O.uv=Transform_tex (V.texcoord, _maintex); //local vectors from vertex position to lightO.lightdir =Objspacelightdir (V.vertex); O.normal=V.normal; returno; } float4 Frag (v2f i): COLOR {i.lightdir=normalize (I.lightdir); I.normal=normalize (i.normal); //Texture SamplingFLOAT4 C =tex2d (_maintex, I.UV); //cos values for light intensity, normal direction, and illumination orientation                floatDiffuse = max (0, Dot (i.normal, i.lightdir)); //Texture Color * source color * Strength parameterc = c * _LIGHTCOLOR0 *Diffuse; returnC2; } ENDCG}} FallBack"Diffuse"}

The Phong illumination model calculates the intensity of specular highlights based on the angle of the reflected vector of the light vector and the line of sight, plus the composition of the diffuse light:

Shader"JAMES/VP Shader/lightmodel-phong"{Properties {_maintex ("Maintex", 2D) =" White"{} _gloss ("Gloss", Float) =1} subshader {Pass {Tags {"Lightmode"="Forwardbase"} cgprogram#pragmaVertex vert#pragmaFragment Frag#include"Unitycg.cginc"                        float_lightcolor0;            Sampler2d _maintex;            FLOAT4 _maintex_st; float_gloss; structv2f {float4 pos:sv_position;                FLOAT2 uv:texcoord0;                FLOAT3 Normal:texcoord1;            FLOAT3 Lightdir:texcoord2; //Illumination DirectionFLOAT3 Reflectlightdir:texcoord3;//Light Reflection DirectionFLOAT3 Viewdir:texcoord4;//Sight Direction            };                v2f Vert (Appdata_full v) {v2f o; O.pos=Mul (UNITY_MATRIX_MVP, V.vertex); O.uv=Transform_tex (V.texcoord, _maintex); O.normal=V.normal; //local vectors from vertex position to lightO.lightdir =Objspacelightdir (V.vertex); //reflection vectors, note the need to use-o.lightdirO.reflectlightdir = Reflect (-O.lightdir, V.normal); //Line of sight, vertex to camera local variableO.viewdir =Objspaceviewdir (V.vertex); returno; } float4 Frag (v2f i): COLOR {i.normal=normalize (i.normal); I.reflectlightdir=normalize (I.reflectlightdir); I.viewdir=normalize (I.viewdir); //Texture SamplingFLOAT4 C =tex2d (_maintex, I.UV); //Diffuse light intensity                floatDiffuse = max (0, Dot (i.normal, i.lightdir)); //Specular light intensity                floatSpecular = max (0, Dot (I.reflectlightdir, i.viewdir)); Specular= Pow (Specular, +) *_gloss; //Texture Color * source color * Strength parameterc = c * _lightcolor0 * (diffuse +specular); returnC2; } ENDCG}} FallBack"Diffuse"}

The Binnphong illumination model calculates the intensity of specular highlights based on the light vector and the half-width vector of the line of sight, along with the angle of the vertex normals, plus the composition of the diffuse light:

Shader"JAMES/VP Shader/lightmodel-binnphong"{Properties {_maintex ("Maintex", 2D) =" White"{} _gloss ("Gloss", Float) =5} subshader {Pass {Tags {"Lightmode"="Forwardbase"} cgprogram#pragmaVertex vert#pragmaFragment Frag#include"Unitycg.cginc"                        float_lightcolor0;            Sampler2d _maintex;            FLOAT4 _maintex_st; float_gloss; structv2f {float4 pos:sv_position;                FLOAT2 uv:texcoord0;                        FLOAT3 Normal:texcoord1;        FLOAT3 Lightdir:texcoord2; //Illumination Direction            };                v2f Vert (Appdata_full v) {v2f o; O.pos=Mul (UNITY_MATRIX_MVP, V.vertex); O.uv=Transform_tex (V.texcoord, _maintex); O.normal=V.normal; //local vectors of vertex->lightO.lightdir =Objspacelightdir (V.vertex); //local vectors of vertex->cameraFLOAT3 Viewdir =Objspaceviewdir (V.vertex); returno; } float4 Frag (v2f i): COLOR {i.lightdir=normalize (I.lightdir); I.normal=normalize (i.normal); //half-width vector, light direction and middle value of line of sightFLOAT3 Halfdir = (i.lightdir + i.normal) *0.5; //Texture SamplingFLOAT4 C =tex2d (_maintex, I.UV); //Diffuse light intensity                floatDiffuse = max (0, Dot (i.normal, i.lightdir)); //Specular light intensity                floatSpecular = max (0, Dot (i.normal, halfdir)); Specular= Pow (Specular, +) *_gloss; //Texture Color * source color * Strength parameterc = c * _lightcolor0 * (diffuse +specular); returnC2; } ENDCG}} FallBack"Diffuse"}

Binnphong less than Phong to calculate a single reflection vector, it will be more concise and efficient.

Learning notes--simple implementation of basic illumination model