Orient by Two Axes

The orient two axes method allows you to precisely orient any one of the three axes and approximately define either of the remaining two axes. MotionView uses a cross product to compute the direction of the third axis and calculates the precise direction of the second axis using another cross product.

  1. Select Orient two axes from the orientation method drop-down menu.
  2. Select an axis to orient from the axes drop-down menu.
  3. Use the collector-combo box to specify the alignment method for the axis.

    Figure 1.

    If you choose the Point or Vector alignment method, use the collector to select the point or vector to which you want to align the axis. Point or vector coordinates are displayed beneath the point or vector label. The coordinates are protected by a lock and can be edited when the lock is green.

    For a point, the axis lies on a line from the origin to the specified point. For a vector, the axis lies on a line parallel to the selected vector.

    If you choose the DxDyDz, enter the global dx, dy, and dz components of the axis in the text boxes. You may also enter a mathematical expression in any of the text boxes to define dx, dy or dz.

  4. To approximate the direction of one of the remaining two axes, select a plane from the planes drop-down menu.
  5. Using the collector-combo box, specify a second point or vector that is in the direction of the second axis.
    The second axis is constructed such that it aligns as closely as possible with the second point or vector. The third axis is computed using a cross product.
Tip: Click [DC] to view the direction cosines' matrix for a coordinate system. See the Direction Cosines topic for additional information.