float VascularSystemData::GetVesselDiameterAroundPos(D3DXVECTOR3 position, int *usedVertex) {

    const int RAY_COUNT = 6;
    D3DXVECTOR3 rayMovement[RAY_COUNT];
    int nr[RAY_COUNT], actualNr;
    float nrDiam[RAY_COUNT];
    float actualDiam = FLT_MAX;

    rayMovement[0] = D3DXVECTOR3(0, 0, (float)INT_MAX);
    rayMovement[1] = D3DXVECTOR3(0, 0, (float)(-INT_MAX));
    rayMovement[2] = D3DXVECTOR3((float)INT_MAX, 0, 0);
    rayMovement[3] = D3DXVECTOR3((float)(-INT_MAX), 0, 0);
    rayMovement[4] = D3DXVECTOR3(0, (float)INT_MAX, 0);
    rayMovement[5] = D3DXVECTOR3(0, (float)(-INT_MAX), 0);

    for (int i = 0; i < RAY_COUNT; i++)
    {
        nr[i] = GetVertexIndexByRay(position, rayMovement[i]);
        nrDiam[i] = GetDiameterByVertex(nr[i]);
        if (nrDiam[i] < actualDiam)
        {
            actualDiam = nrDiam[i];
            actualNr = i;
        }
    }

    if (usedVertex != NULL)
        *usedVertex = actualNr;

    return  actualDiam;
}