Raymarching-Shader-Template/Raymarching.cginc at master · emymin/Raymarching-Shader-Template · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
#ifndef RAYMARCHING
#define RAYMARCHING

#include "UnityCG.cginc"
#include "UnityLightingCommon.cginc"

float GetPosHitpos(float4 vertex, out float3 cameraPos,out float3 hitPos){
    #if WORLDSPACE
    cameraPos = _WorldSpaceCameraPos;
    hitPos = mul(unity_ObjectToWorld, vertex);
    #else
    cameraPos = mul(unity_WorldToObject, float4(_WorldSpaceCameraPos,1));
    hitPos=vertex;
    #endif
    return 0;
}

float3 GetNormal(float3 p) {
    float2 e = float2(1e-2, 0);

    float3 n = GetDist(p) - float3(
        GetDist(p-e.xyy),
        GetDist(p-e.yxy),
        GetDist(p-e.yyx)
    );

    return normalize(n);
}

float Raymarch(float3 ro, float3 rd) {
    float dO = 0;
    float dS;
    for (int i = 0; i < MAX_STEPS; i++) {
        float3 p = ro + rd * dO;
        dS = GetDist(p);
        dO += dS;
        if (dS<SURF_DIST || dO>MAX_DIST) break;
    }
    return dO;
}


//LIGHTING
//====================

float3 LightColor(float3 p,float3 n,float3 lightPos,float3 lightColor,float attenuation){

    #if !WORLDSPACE
    p=mul(unity_ObjectToWorld,p);
    n=UnityObjectToWorldNormal(n);
    #endif


    float3 lightVec = p-lightPos;
    float3 lightDir = normalize(lightVec);

    float light = saturate(dot(n,lightPos.xyz));
    light/=1+attenuation*dot(lightVec,lightVec);

    return lightColor*light;
}

float3 CalculateLighting(float3 p,float3 n,float3 col){

    float3 lightColor=1;

    #if LIGHTING
    lightColor=0;

    float3 lightPos=_WorldSpaceLightPos0;
    lightColor+=LightColor(p,n,lightPos,_LightColor0,1);

    /*float fac;
    for(int i=0;i<4;i++){
        lightPos=(unity_4LightPosX0[i], unity_4LightPosY0[i], unity_4LightPosZ0[i]);
        lightColor+=LightColor(p,n,lightPos,unity_LightColor[i],unity_4LightAtten0[i]);
    }*/

    lightColor+=ShadeSH9(half4(n,1));

    #endif

    return lightColor*col;
}

float GetDepth(float3 p, float d){
    #if WORLDSPACE==0
        p=mul(unity_ObjectToWorld,float4(p,1));
    #endif

    float3 viewPos = mul(UNITY_MATRIX_V, float4(p, 1.0)).xyz;
    float linearZ = -viewPos.z;
    return (1.0 - _ZBufferParams.w * linearZ) / (linearZ * _ZBufferParams.z);
}

#endif