Motion Blur Controls
3D Stroke has the following Motion Blur controls:
Motion Blur
The pop-up offers these choices: On, Comp Settings and Off. On turns motion blur on, no matter what the current settings are in the host application. Shutter angle and phase are set below. Comp Settings means the comp settings for motion blur are used. This is the default and recommended. Shutter angle and phase are taken from the compostion settings. Off means motion blur is not rendered.
Note: In host applications other than Adobe After Effects, only the On and Off controls will appear.

Shutter Angle
The angle controls how long time the virtual shutter stays open to capture one frame. 360 means it's open the entire duration of the frame, while 180 means it is open half the duration of a frame. The maximum value is 720, which causes the shutter to be open for twice the frame time, causing exaggerated motion trails.

Shutter Phase
This value controls when the shutter opens. 0 means at start of frame.
After Effects tip: If this value is set to negative and the plug-in uses the comp camera, then the camera layer needs to start one frame before the layer to which 3D Stroke is applied.

Levels
This value sets the number of samples generated per frame for the motion blur. Higher values create a smoother blur but mean longer render times. If the stroke movement is very fast, this value should be high to make smooth images. If movement is slow, this should be set low (or motion blur should be turned off) to reduce render time. This setting can be keyframed for optimal performance.
Opacity and Transfer Mode
The Opacity sets how transparent the stroke appears against the background or on top of other strokes.

The Transfer Mode pop-up sets the transfer mode for the plug-in. This can be used when stacking many 3D Stroke plugs in one layer. Leave the first at None and the rest switch to (for example) Normal. The 3D Stroke plug-in offers the following modes: None, Normal, Add, Multiply, Overlay, Soft Light, Hard Light, Color Dodge, Color Burn, Darken, Lighten, Difference, Exclusion, Hue, Saturation, Color and Luminosity.