Reducing Keys using Filters

This topic shows how to reduce keys using filters. To follow the instructions, download the file and script from http://area.autodesk.com/downloads/scripts/motionbuilder-animation-scripts.

1. Open the filters_key_reducer.fbx file in MotionBuilder. The cube's FCurves appear as shown in the following figure.

   

2. Run the filters_constant_key_reducer.py script to reduce the constant keys on the FCurve. The x FCurve for translation is modified as shown in the following figure.

   

Following are the points to keep in mind:

• FBFilterManager() is the entrance to all filters.
• FBFilterManager().CreateFilter ('Constant Key Reducer') creates a constant key reducer.
• A filter always has two inputs: start time and stop time.
• lFilter.Apply (lModel.Translation.GetAnimationNode(), True) applies the filter to the model’s animation node.

Follow these instructions to retain the FCurve shape.

1. Open the filters_key_reducer.fbx file in MotionBuilder. The FCurves appear as shown in the following figure.

   

2. Run the filters_key_reducer.py script to reduce the keys on the FCurves. The shape does not change as shown in the following figure.