# Ghosts Cells in ParaView

## The SQ Image Ghosts Filter

Some of the SciberQuest ToolKit filters operating on Cartesian grids require ghost cells to function. These can be provided by the SQ BOV reader , however, with each new request for ghost cells the reader will read the entire dataset which results in two full pipeline executions. For this reason filter that require ghost cells should always be used with the SQ Image Ghost filter that generates the requested ghost cells with re-executing the entire pipeline.

The following figure illustrates the use of SQ Image Ghosts in ParaView.

Figure 1. Image Ghosts filter example.

## SQ filters that require ghost cells

The following filters require an instance of SQ Image Ghosts immediately upstream.

- SQ Kernel Convolution
- SQ Vortex filter