Measuring distances

The image below illustrates the Distance tool.

Distances are only precise in a plane perpendicular to the camera. You first have to calibrate this plane by defining a reference distance. To do this, put an object of known length at the position where the movement will be performed (the width of the mat in the above example).


To measure distances, proceed as follows:

1.	Right-click on the Time button and select Distance from the context menu.

2.	Click, hold and move the mouse cursor to draw the reference distance (the one with the dashed line in the image above)

3.	Right-click on the reference distance and select Set as reference... from the context menu. The following dialog opens

4.	Enter the size of the reference object.

5.	Select the Distance tool again and draw the distance (vertical line in the example above). It will be computed based on the line length and the reference value.

The measurement precision relies on many factors such as the distance between the camera and the performer, the camera zooming factor, the precision of the perpendicularity between the camera axes and the plane in which the movement is performed, etc... Try to be as precise as possible when setting the reference distance. For example, use a well defined and distinct marker on the floor and use zoom tools to enlarge the image when setting the reference distance.