A Texture3D SDF function to be used inside Unity shader graph

RaymarchSDF.hlsl

#ifndef RAYMARCHSDFINCLUDE_INCLUDED
#define RAYMARCHSDFINCLUDE_INCLUDED

#define STEPS 256
#define MAX_DISTANCE 500
#define MIN_DISTANCE 0.001

#if !SHADERGRAPH_PREVIEW
    #include "Packages/com.unity.render-pipelines.core/ShaderLibrary/Texture.hlsl"
    #include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Core.hlsl"
#endif

float3 Normal(float3 position, UnityTexture3D Texture, UnitySamplerState Sampler)
{    
    float2 e = float2(1.0,-1.0) * 0.5773;
    const float eps = 0.0005;
    return normalize(e.xyy * SAMPLE_TEXTURE3D(Texture, Sampler, position + e.xyy*eps) + 
                      e.yyx * SAMPLE_TEXTURE3D(Texture, Sampler, position + e.yyx*eps) + 
                      e.yxy * SAMPLE_TEXTURE3D(Texture, Sampler, position + e.yxy*eps) + 
                      e.xxx * SAMPLE_TEXTURE3D(Texture, Sampler, position + e.xxx*eps));
}

void Raymarch_float(float3 RayOrigin, float3 RayDirection, UnityTexture3D Texture, UnitySamplerState Sampler, float3 PositionOffset, out float3 OutPosition, out float OutDistance, out float3 OutNormal)
{
    float distanceOrigin = 0;
    float distanceSurface;

    for (int i = 0; i < STEPS; i++)
    {
        float3 position = RayOrigin + distanceOrigin * RayDirection + PositionOffset;
        float4 map = SAMPLE_TEXTURE3D(Texture, Sampler, position);
        distanceSurface = map;
        distanceOrigin += distanceSurface;

        if (distanceSurface < MIN_DISTANCE || distanceOrigin > MAX_DISTANCE) break;
    }

    if (distanceOrigin < MAX_DISTANCE)
    {
        OutPosition = RayOrigin + distanceOrigin * RayDirection + PositionOffset;
        OutDistance = distanceOrigin;
        OutNormal = Normal(OutPosition, Texture, Sampler);
    }
    else
    {
        OutPosition = float3(0,0,0);
        OutDistance = 0;
        OutNormal = float3(0,0,0);
    }
}

#endif

Shader graph example: