Although
it is not mandatory to define a ground plane in your image, it helps
orient the reconstruction of the cameras.
To define the auto track ground plane:
In the Plane section of the Camera Tracking
menu, enable Define.
NoteIf you selected Pan
and Tilt as the camera type (or if the Auto Detect switched to Pan
and Tilt) the Plane Define button is not available. The rest of
the settings in this group are still available, but only for orientation
purposes.
Select a minimum of three points in the
image that represent the plane of the X/Z axes, such as the ground,
a table, or any flat surface.
The selected points appear
as red squares with white crosses.
TipYou may want to disable
the tracker temporarily and point display options (or raise the
transparency level) to help you find and select the plane points.
Use the Position and Rotation controls
to define the orientation of the ground plane.
Use the Scale field to specify the scale
of the scene.