cvr-props/Assets/raymarched/Interactive/raymarcher.cginc

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4.9 KiB
HLSL

#ifndef RAY_MARCH_LIB_INCLUDED
#define RAY_MARCH_LIB_INCLUDED
/*
define IS_SECONDARY_SHAPE to only render the second shape
*/
#include "UnityCG.cginc"
#include "UnityLightingCommon.cginc"
struct appdata
{
float4 vertex : POSITION;
};
struct v2f
{
float4 vertex : SV_POSITION;
float3 ro : TEXCOORD1;
float3 hitPos : TEXCOORD2;
};
struct fragOut
{
fixed4 col : SV_Target;
float depth : SV_Depth;
};
int _MaxSteps;
float _MaxDist;
float _SurfDist;
v2f vert (appdata v) {
v2f o;
o.vertex = UnityObjectToClipPos(v.vertex);
//object space
o.ro = mul(unity_WorldToObject, float4(_WorldSpaceCameraPos, 1));
o.hitPos = v.vertex;
//world space
//o.ro = _WorldSpaceCameraPos;
//o.hitPos = mul(unity_ObjectToWorld, v.vertex);
return o;
}
float smin(float a, float b, float k) {
return min(a, b) - pow(max(k - abs(a-b), 0), 3)/(6*k*k);
}
float sdSphere(float3 p, float3 o, float r) {
return length(p - o) - r;
}
float sdBox(float3 p, float3 dim) {
return length(float3(
max(abs(p.x) - dim.x/2.0, 0),
max(abs(p.y) - dim.y/2.0, 0),
max(abs(p.z) - dim.z/2.0, 0)));
}
float sdLine(float3 p, float3 a, float3 b, float r) {
float3 pa = p - a;
float3 ba = b - a;
float h = clamp(dot(pa, ba) / dot(ba, ba), 0, 1);
return length(pa - ba * h) - r;
}
float sdCappedTorus( float3 p, float2 sc, float ra, float rb) {
p.x = abs(p.x);
float k = (sc.y*p.x>sc.x*p.y) ? dot(p.xy,sc) : length(p.xy);
return sqrt( dot(p,p) + ra*ra - 2.0*ra*k ) - rb;
}
float3 RotateY(float3 p, float a) {
return mul(float3x3(cos(a), 0, sin(a), 0, 1, 0, -sin(a), 0, cos(a)), p);
}
float Kijetesantakalu(float3 p, float r) {
float d = sdSphere(p, float3(0, 0, 0.2f), r);// left eye
d = min(d, sdSphere(p, float3(0.15f, 0, 0.2f), r)); // right eye
d = min(d, sdLine(p, float3(0, 0, -0.4f), float3(-0.35f, 0, -0.4f), r)); // bottom line
d = smin(d, sdLine(p, float3(0, 0, -0.4f), float3(-0.1f, 0, -0.15f), r), 0.003f); // leg hook
d = min(d, sdLine(p, float3(0.15f, 0, -0.4f), float3(0.15f, 0, -0.1f), r)); // middle leg
d = min(d, sdLine(p, float3(0.3f, 0, -0.4f), float3(0.3f, 0, 0), r)); // front leg
d = smin(d, sdLine(p, float3(0.45f, 0, 0.1f), float3(0.3f, 0, 0), r), 0.003f); // lower snout
d = smin(d, sdLine(p, float3(0.45f, 0, 0.1f), float3(0.2f, 0, 0.35f), r), 0.003f); // upper snout
d = smin(d, sdLine(p, float3(0.2f, 0, 0.45f), float3(0.2f, 0, 0.35f), r), 0.003f); // ear
float an = 0.9;
d = smin(d, sdCappedTorus((RotateY(p, 0.8f) - float3(0.15f, 0, -0.05f)).xzy, float2(sin(an),cos(an)), 0.4, r), 0.003f); // ear
d = smin(d, sdLine(p, float3(-0.25f, 0, 0), float3(-0.25f, 0, -0.4f), r), 0.003f); // back
d = smin(d, sdLine(p, float3(-0.25f, 0, -0.1f), float3(-0.35f, 0, -0.1f), r), 0.003f); // tail top
d = smin(d, sdLine(p, float3(-0.35f, 0, -0.1f), float3(-0.35f, 0, -0.4f), r), 0.003f); // stripe
an = 3.1415f*0.5;
d = smin(d, sdCappedTorus((RotateY(p, an) - float3(-0.25f, 0, 0.35f)).xzy, float2(sin(an),cos(an)), 0.15f, r), 0.003f); // tail
return d;
}
float FirstShape(float3 p) {
return Kijetesantakalu(p, 0.05f);
}
float SecondShape(float3 p) {
// return sdBox(p, 0.3f) - 0.01f;
// return Kijetesantakalu(p, 0.04f) - 0.01f;
return sdSphere(p, 0, 0.3f);
}
float GetDist(float3 p) {
#ifdef IS_SECONDARY_SHAPE
return SecondShape(p);
#else
#ifdef BASE_PASS
return FirstShape(p);
#else
float first = FirstShape(p);
float3 second_pos = mul(unity_WorldToObject, _WorldSpaceLightPos0);
float second = SecondShape(p - second_pos);
return smin(first, second, 0.15f);
#endif
#endif
}
//marches a ray through the scene
float Raymarch(float3 ro, float3 rd) {
float rayLen = 0;// total distance marched / distance from origin
float dist; // distance from the raymarched scene
for ( int i = 0; i < _MaxSteps; i++)
{
//position = origin + distance * direction
float3 p = ro + rayLen * rd;
dist = GetDist(p);
rayLen += dist;// move forward
if (dist < _SurfDist || rayLen > _MaxDist) {
break;
}
}
return rayLen;
}
float3 GetNormal(float3 p) {
float2 e = float2(0.001, 0);
float3 n = GetDist(p) - float3(
GetDist(p-e.xyy),
GetDist(p-e.yxy),
GetDist(p-e.yyx));
return normalize(n);
}
fragOut frag (v2f i) {
#ifndef IS_SECONDARY_SHAPE
#ifndef BASE_PASS
if (length(_LightColor0 - float4(0,0,1,0)) > 0.01f ){
discard;
}
#endif
#endif
float3 ro = i.ro;
float3 rd = normalize(i.hitPos - ro);
float d = Raymarch(ro, rd);
fixed4 col = 1;
if (d >= _MaxDist)
{
discard;
}
float3 p = ro + rd * d;
float3 n = GetNormal(p);
// col.rgb = max(dot(n, normalize(float3(1,0.5,1))), 0.05f);
col.rgb = lerp(0, float3(0,1,1), pow(1 - dot(-rd, n), 3));
// col *= float4(d, 1, 1, 1);
fragOut o;
o.col = col;
// o.col = _LightColor0;
float4 vClipPos = mul(UNITY_MATRIX_VP, mul(unity_ObjectToWorld, float4(p, 1)));
float zDepth = vClipPos.z / vClipPos.w;
#if !defined(UNITY_REVERSED_Z) // basically only OpenGL (unity editor on linux)
zDepth = zDepth * 0.5 + 0.5; // remap -1 to 1 range to 0.0 to 1.0
#endif
o.depth = zDepth;
return o;
}
#endif