<<VilGebra`

anchoventana=2;
ContourPlot3D[4*x^2-8*x+4*y^2-8*y+4*z^2-8*z+12==1,{x,-anchoventana,anchoventana},{y,-anchoventana,anchoventana},{z,-anchoventana,anchoventana},Axes->True,AxesOrigin->{0,0,0},AxesLabel->{"x","y","z"},Boxed->False]