1. In order to define the spiral distributed sub-regions (sampling volume) features, some parameters of the script should be adjusted to match your analysis needs. These parameters are located in the code area labeled as USER SETTING.
  1. Set the Z planes range.
    FIRST_PLANE defines the lower Z plane of the sub-regions ROI.
    LAST_PLANE defines the higher Z plane of the sub-regions ROI.
    The values of -1 set the Z planes range equal to the whole volume depth (total number of Z Planes available).
  2. STEP_ANGLE defines the step size in degrees. The boxes will be positioned on the spiral curve every STEP_ANGLE.
  3. SPIRAL_LOOP defines the number of loops (concentric spirals). Any single loop is a complete 360° spiral. Values less than 1.0 draw a partial spiral.

  4. COEFFICENT_B is the coefficient used to define the distance between the loops of the concentric spiral.

  5. BOX_HEIGHT sets the height of the boxes (Y).
    BOX_WIDTH sets the width of the boxes (X).
    Both are expressed in pixels.

Set the distance of the loops and their numbers according to the size of the boxes. Wrong parameters setting can make the boxes overlap, especially inside the inner part of the spiral.