while(x < cellsx && x >= 0 && y < cellsy && y >= 0
                      && z < cellsz && z >= 0)
                {
                    voxelValue = model[z * (cellsy) * (cellsx) + y * (cellsx) + x ];
                    alpha = (voxelValue & 0xF0)/256.0;
                    if (alpha <  1 - alphaSencity) alpha = 0;

                    if (alpha > 0)
                    {
                        color = (voxelValue & 0xF)/16.0;
                        if (color > colorSencity) color = 1;


                        prevColor = alpha*prevColor + (1 - alpha) * color;


                        if (prevColor <= 0)
                        {
                            prevColor = 0;
                            break;
                        }
                    }

                    //qDebug() << x << y << z;


                    if(ray.x() && tMaxX <= tMaxY && tMaxX <= tMaxZ)
                    {
                        tMaxX += tDeltaX;
                        x += stepX;
                    }
                    else if(ray.y() && tMaxY <= tMaxZ && tMaxY <= tMaxX)
                    {
                        tMaxY += tDeltaY;
                        y += stepY;
                    }
                    else
                    {
                        tMaxZ += tDeltaZ;
                        z += stepZ;
                    }
                }