Apple Logic Pro 9 - Manual (Page 1127)

Configuring a Transformer Object
Double-clicking a transformer icon opens the Transformer window, where you can set
the conditions and operations.
Setting the Operation Mode
Use the pop-up menu at the top of the Transformer window to define how a transformer
handles MIDI events. You can choose between the operation modes outlined below.
Apply Operation and Let Non-Matching Events Pass Thru
MIDI events that match the condition are processed. MIDI events that don’t conform to
the condition are passed through.
Apply Operation and Filter Non-Matching Events
MIDI events that conform to the condition are processed. MIDI events that do not conform
to the condition are not passed through.
Filter Matching Events
All MIDI events that match the condition are filtered out. MIDI events that don’t conform
to the condition are passed through.
Copy Matching Events and Apply Operation
All MIDI events that conform to the condition are copied, and the copy is processed. The
original and transformed copy (plus any MIDI events that don’t conform to the condition)
are passed through. The unchanged original is parsed (processed) before the transformed
copy.
1127 Chapter 37 Environment Objects Reference