This topic lists the density constraints:
densityFillKeepout
maxDensity
maxDiffDensity
maxInterLayerDensityGradient
minDensity
minDensityHole
minFillPatternSpacing
minFillToFillSpacing
minPgFillBoundarySpacing
minPgFillClockSpacing
minPgFillFloatingFillSpacing
minPgFillPgSpacing
minPgFillSignalSpacing
minPgFillSpacing
Tcl Constraint Commands
Manage Constraints