HEADERS:

//Voxel type
struct SVT      // Smooth Voxel Type
{
    uint16_t density;  // Density
    uint8_t material;  // Material
    uint8_t light;  // Light
    uint32_t color; // Color
    bool isSmooth;
    SVT();
    SVT(uint8_t m, uint8_t d = 255);
    SVT &operator +(const SVT& other);
    SVT &operator -(const SVT& other);
    SVT &operator /(const int& other);
    SVT &operator +=(const SVT& other);
    SVT &operator -=(const SVT& other);
    SVT &operator /=(const int& other);
};

class PGFMarchingCubesController
{
public:
    typedef uint8_t DensityType;
    typedef uint8_t MaterialType;
    PGFMarchingCubesController(void);
    DensityType convertToDensity(SVT voxel);
    MaterialType convertToMaterial(SVT voxel);
    DensityType getThreshold(void);
    void setThreshold(DensityType tThreshold);
private:
    DensityType m_tThreshold;
};

class PGFIsQuadNeeded
{
public:
    bool operator()(SVT back, SVT front, uint32_t& materialToUse);
};

SOURCES:

SVT::SVT(): density(0), material(0), light(0), isSmooth(true){}

SVT& SVT::operator +(const SVT &other)
{
    this->density += other.density;
    return *this;
}

SVT& SVT::operator -(const SVT &other)
{
    this->density -= other.density;
    return *this;
}

SVT& SVT::operator /(const int &other)
{
    this->density /= other;
    return *this;
}
/**/

SVT& SVT::operator +=(const SVT &other)
{
    this->density += other.density;
    return *this;
}

SVT& SVT::operator -=(const SVT &other)
{
    this->density -= other.density;
    return *this;
}

SVT& SVT::operator /=(const int &other)
{
    this->density /= other;
    return *this;
}

...

PGFMarchingCubesController::PGFMarchingCubesController()
    :m_tThreshold(127)
{
}

PGFMarchingCubesController::DensityType PGFMarchingCubesController::convertToDensity(SVT voxel)
{
    return voxel.density;
}

PGFMarchingCubesController::MaterialType PGFMarchingCubesController::convertToMaterial(SVT voxel)
{
    return voxel.material;
}

PGFMarchingCubesController::DensityType PGFMarchingCubesController::getThreshold()
{
    return m_tThreshold;
}

void PGFMarchingCubesController::setThreshold(PGFMarchingCubesController::DensityType tThreshold)
{
    m_tThreshold = tThreshold;
}


.....

The actual code:
Actually a boolean cloud, setting densities either 0 or 255.

ch->voxdata = new RawVolume<SVT>(Region(-1,-1,-1,ch->sx+1,ch->sy+1,ch->sz+1));

    //Generate SOME data into them \paging test!
    chunk* c = ch;
    for(int xi=-1; xi<=ch->sx+1; ++xi)
        for(int yi=-1;yi<=ch->sy+1;++yi)
        {
            float pval = perlin.Get(float(xi+ch->x*ch->sx)/float(ch->sx), float(yi+ch->y*ch->sy)/float(ch->sy));
            pval += 1.0;  //0..2;
            pval /= 2.0;  //0..1
            pval *= ch->sz;   //reach the z
            int zz = pval;
            //cout << zz << ", ";
            for(int zi=-1;zi<pval;++zi)
            {
                SVT vx;
                vx.density = 255;
                vx.material = 1;
                vx.color = Ogre::ColourValue(1,1,1,1).getAsRGBA();
                vx.light = 255;
                ch->voxdata->setVoxelAt(xi,yi,zi,vx);
            }
        }

.... LATER ....

        delete c->newmesh;
        c->newmesh =
            new SurfaceMesh<PositionMaterialNormal>();    //must DELETE it!

        //Smooth chunk
        RawVolume<SVT> tempVolume(Region(-1,-1,-1,c->sx+1,c->sy+1,c->sz+1));
        LowPassFilter< RawVolume<SVT>, RawVolume<SVT>, SVT >
                lpf(c->voxdata,     Region(-1,-1,-1,c->sx+1,c->sy+1,c->sz+1),
                    &tempVolume,    Region(-1,-1,-1,c->sx+1,c->sy+1,c->sz+1),
                3);
        lpf.execute();

        MarchingCubesSurfaceExtractor< RawVolume<SVT>, PGFMarchingCubesController >
                ext2(&tempVolume, Region(0,0,0,c->sx,c->sy,c->sz), c->newmesh);
        ext2.execute();

class PGFMarchingCubesController
{
public:
    typedef uint8_t DensityType;
    typedef uint8_t MaterialType;

class PGFMarchingCubesController
{
public:
    typedef uint16_t DensityType;
    typedef uint8_t MaterialType;