# BoundaryPixelTracker Plugin¶

BoundaryPixelTracker plugin keeps a list of boundary pixels for each cell. The syntax is as follows:

<Plugin Name="BoundaryPixelTracker">
<NeighborOrder>1</NeighborOrder>
</Plugin>


This plugin is also used by other plugins as a helper module. Examples use of this plugin is found in Demos/PluginDemos/BoundaryPixelTracker_xxx.

# GlobalBoundaryPixelTracker Plugin¶

GlobalBoundaryPixelTracker plugin tracks boundary pixels of all the cells including Medium. It is used in a Boundary Walker algorithm where instead of blindly picking pixel copy candidate we pick it from the set of pixels comprising boundaries of non frozen cells. In situations when lattice is large and there are not that many cells it makes sense to use BoundaryWalker algorithm to limit number of pixel picks that would not lead to actual pixel copy.

Note

BoundaryWalkerAlgorithm does not really work with OpenMP version of CC3D which includes all versions starting with 3.6.0.

Take a look at the following example:

<Potts>
<Dimensions x="100" y="100" z="1"/>
<Anneal>10</Anneal>
<Steps>10000</Steps>
<Temperature>5</Temperature>
<Flip2DimRatio>1</Flip2DimRatio>
<NeighborOrder>2</NeighborOrder>
<MetropolisAlgorithm>BoundaryWalker</MetropolisAlgorithm>
<Boundary_x>Periodic</Boundary_x>
</Potts>

<Plugin Name="GlobalBoundaryPixelTracker">
<NeighborOrder>2</NeighborOrder>
</Plugin>


Here we are using BoundaryWalker algorithm (Potts section) and subsequently we list GlobalBoundaryTracker plugin where we set neighbor order to match that in the Potts section. The neighbor order determines how “thick” the overall boundary of cells will be. The higher this number the more pixels will belong to the boundary.

# PixelTracker Plugin¶

PixelTracker plugin allows storing list of all pixels belonging to a given cell. The syntax is as follows:

<Plugin Name="PixelTracker">
<TrackMedium/>
</Plugin>


This plugin is also used by other modules (e.g. Mitosis) as a helper module. Simple example can be found in Demos/PluginDemos/PixelTrackerExample. Beginning with 4.1.2, medium pixels can be optionally tracked using TrackMedium. This feature is automatically enabled by attaching a Fluctuation Compensator to a PDE solver.