float SierpinskiTriangle2(float3 p)
{
	float Scale = 2.0;
	float3 Offset = float3(1, 1, 1);
	int n = 0;
	while (n < 1) {
		if (p.x + p.y < 0)
			p.xy = -p.yx; // fold 1
		if (p.x + p.z < 0)
			p.xz = -p.zx; // fold 2
		if (p.y + p.z < 0)
			p.zy = -p.yz; // fold 3
		p = p * Scale - Offset * (Scale - 1.0);
		n++;
	}
	return (length(p)) * pow(Scale, -float(n));
}
...
float DistanceField(float3 p)
{
	return sierpinski3d(p);
}
...
fixed4 RayMarch(float3 ro, float3 rd, float depth)
{
	fixed4 result = fixed4(1,1,1,1);
	const int max_iteration = _MaxIterations;
	float t = 0; //distance travelled along the ray direction

	for (int i = 0; i < max_iteration; i++)
	{
		if (t > _maxDistance || t >= depth)
		{
			result = fixed4(rd,0);
			break;
		}

		float3 p = ro + rd * t;
		float d = DistanceField(p);
		if (d < _Accuracy)
		{
			float3 n = GetNormal(p);
			float3 s = Shading(p,n);
			result = fixed4(s,1);
			break;
		}
		t += d;
	}
	return result;
}
...
fixed4 frag(v2f i) : SV_Target
{
	float depth = LinearEyeDepth(tex2D(_CameraDepthTexture, i.uv).r);
	depth *= length(i.ray);
	fixed3 col = tex2D(_MainTex, i.uv);
	float3 rayDirection = normalize(i.ray.xyz);
	float3 rayOrigin = _WorldSpaceCameraPos;
	fixed4 result = RayMarch(rayOrigin, rayDirection, depth);
	return fixed4(col * (1.0 - result.w) + result.xyz * result.w,1.0);
}