Asset Creation: Maya Scenography Modeling - Creating Games with Unity and Maya - page 29

Step 27: Create a cylinder with 60 (yes, 60) Axis Divisions. Do this one of
two ways. Either create the cylinder (Create>Polygon Primitives>Cylinder),
then in the Channel Box, select the polyCylinder node in the INPUTS section
and change the Subdivision Axis entry there. Or, select Create>Polygon
Primitives>Cylinder (Options) and in the Polygon Cylinder Options box,
change the Axis Division entry to 60.
Rotate and translate the cylinder to match Figure 2.25 .

Figure 2.25 Placed elements ready for Boolean function.

Warnings and Pitfalls
Although it is a bit
difficult to see in the
screenshot, that cylinder
completely penetrates
the altered cube and
comes out the other side.
For this Boolean function
to work, the hole object
(the cylinder) must be
longer than the object it
is being subtracted from.

Why?
“60 axis division?!” you cry incredulously, “all this talk of being
efficient with our polycount and you make such a heavy primitive!
What gives?” Yes, yes, 60 subdivisions is a lot, and it's important to be
very careful where to use such a heavy (high polycount) object. This is
one of those places. The reason is that the curve across that archway
is very large, and in fact at times in the game it may indeed cover the
entire screen. When a curve spans such a large visual space, this is
a good place to blow some of the polygon budget. When elements
are small on screen—or never get much scrutiny in the course of
game play—this is where to stay super stingy with polys. Note that
although we started out with a 60-subdivision shape, we actually only
used half of them, so there are only 30 subdivisions across the top of
that arch.

Step 28: Tweak the cylinder to make an arched entry (rather than a round
tube) . Press the space bar (to move into four-panel mode), then move
the mouse over the front View panel, and press the space bar again.
This will make the front View panel full screen. Switch to vertex mode
(right-click the cylinder and select Vertex from the hotbox) and Marquee-
select the vertices that make up the bottom half of the sphere. Use the
Translate tool to move them down below the bottom of the modified box
( Figure 2.26 ).
Step 29: Subtract the cylinder from the modified box . In Object Mode,
select the box, then Shift-select the cylinder (the order of selection is
important here). Choose Polygons>Mesh>Booleans>Difference. The result
should be similar to Figure 2.27 .