Problem: Contour lines look blocky, appearing to trace raster cell boundaries
Occasionally, contours may be created that have square or blocky outlines, appearing to follow raster cell boundaries.
The raster values are integers, which align with the contour. This is not a bug, it is exact contouring of the data.
Solution or Workaround
If you want smoother contours, select one of the options below:
- Smooth the surface
This is used to perform a FocalStatistics on the raster with the mean statistic. To use the FocalStatistics tool, have Spatial Analyst installed.
- Adjust the Base contour
This offsets the Base contour so that the contours no longer pass directly through the mesh points. The offset can be very small; values as small as 0.0001 are effective.
- Smooth the surface and adjust the Base contour combined
Combining both methods is particularly effective. It produces smoother, therefore aesthetically more pleasing contours.