Blank

Now we have our high-poly detailed mesh (in actual fact it probably wont be
that high in the triangle count but with a normal map we can lower this to 28!
Great for a console/PC engine). Marque-select all your shapes and
'combine' them together. This can be found in the 'Mesh' drop-down menu,
this should turn all your polygonal objects into one final object. Select your
new combined shape and in the bottom-right of your UI window create a
layer; Right-Click Hold on the layer and 'add selected' (see fig4)

So now we need to build our low-poly game mesh and this will simply be a
cube! because this is all we need so create a cube and then select each
vertices and snap them to the high-poly's cabinet edges. To Vert-snap
select the vert, hold 'v' and select the dotted circle in the center of your move
(translate) gizmo and drag over to another vert.

I may add some divisions to the cube as well - this will make it easier to
reuse some of the normal map when we have finished (this will make sense
later) so by selecting your low-poly cube and going to your side view port I'll
use the 'Cut Face Tool' in the 'Edit Mesh' drop down menu. By clicking and
dragging the mouse in the direction you want the cut to be made you will
split the polygons. If you need to adjust the split's position go into the
vertices component mode and move them so each split is along every
draw's edge.

In Fig.5 I have just moved my high-poly model aside for now so you can see
my actual game-model's final shape. Here you can see my splits I have
made so I have a division for each drawer.

You should end up with a cube intersecting your detailed cabinet - This is
perfect because when it is time to bake/transfer our detail to the 2D normal
map texture they must be in the same world space (in other words occupy
the same area and intersect as close as possible - See fig5).