Game Development Reference
Figure 12.18 includes a second update to the Unlock Item TFD. Flow 6 originally start-
ed at HavePointsItemUnlocked but now it goes from NoPointsHaveItem to the OUT box. For
this case, all flows coming from both HavePointsItemUnlocked and NoPointsHaveItem were
re-evaluated to add up to 100% from each originating state.
For HavePointsItemUnlocked , one or more percentages need to increase since that state
lost a flow. You can give flow 12 the 10% that used to be allocated to flow 6. That
would not overly inflate the usage for flow 7 and it keeps flow 5's usage small. As
Figure 12.18 shows, flow 12 now has a 20% usage instead of its original 10% value.
Additionally, one or more flows coming from NoPointsHaveItem must now be reduced to
make room for the new flow. Since flow 6 is an Exit flow, it must have a 10% usage.
Two other flows come from NoPointsHaveItem : flow 8 with a 10% usage and flow 9 with
a 90% usage. Reducing flow 8 by 10% will put it at 0%, meaning it will never be select-
ed for any Cleanroom paths for this TFD. Instead, take away 5% from flow 8 and 5%
from flow 9. The new percentages for these flows are reflected in Figure 12.18.
Alternatively, you could have taken 10% away from flow 9 and left flow 8 at 10%. Your
choice depends on what distribution you think best reflects the expected relative usage
of these flows according to the game player, mode, or data you are trying to model.
Figure 12.18 Unlock Item TFD with altered flows 6 and 9.