Grow streets settings.
@example:
# Settings class used to control parameters for growStreets operation
streetlayer = ce.getObjectsFrom(ce.scene, ce.withName("streets"))
growsettings = GrowStreetsSettings()
growsettings.setBasicSettingsPatternOfMajorStreets(GrowStreetsSettings.RADIAL)
growsettings.setBasicSettingsPatternOfMinorStreets(GrowStreetsSettings.RADIAL)
heightmap = ce.getObjectsFrom(ce.scene, ce.isMapLayer, ce.withName('Heightmap'))[0]
growsettings.setEnvironmentSettingsHeightmapLayer(heightmap)
obstaclemap = ce.getObjectsFrom(ce.scene, ce.isMapLayer, ce.withName('Obstacle'))[0]
growsettings.setEnvironmentSettingsObstaclemapLayer(obstaclemap)
ce.growStreets(streetlayer, growsettings)
Methods defined here:
getAdvancedSettingsAngleOffsetOfMajorStreets
getAdvancedSettingsAngleOffsetOfMajorStreets(self):
Gets AdvancedSettingsAngleOffsetOfMajorStreets field. Offset angle which is added to every major street before creation (e.g. to create spiral street patterns).
@return: Value of AdvancedSettingsAngleOffsetOfMajorStreets field. [float]
getAdvancedSettingsAngleOffsetOfMinorStreets
getAdvancedSettingsAngleOffsetOfMinorStreets(self):
Gets AdvancedSettingsAngleOffsetOfMinorStreets field. Offset angle which is added to every minor street before creation (e.g. to create spiral street patterns).
@return: Value of AdvancedSettingsAngleOffsetOfMinorStreets field. [float]
getAdvancedSettingsDevelopmentCenterPreference
getAdvancedSettingsDevelopmentCenterPreference(self):
Gets AdvancedSettingsDevelopmentCenterPreference field. Development center sampling preference. Corresponds to the number of samples before taking the node which is the nearest to the center.
@return: Value of AdvancedSettingsDevelopmentCenterPreference field. [int]
getAdvancedSettingsMinimalAngle
getAdvancedSettingsMinimalAngle(self):
Gets AdvancedSettingsMinimalAngle field. If a new street intersects/snaps with the existing streetnetwork and the in-between angle is below this threshold, the new street is dismissed.
@return: Value of AdvancedSettingsMinimalAngle field. [float]
getAdvancedSettingsSnappingDistance
getAdvancedSettingsSnappingDistance(self):
Gets AdvancedSettingsSnappingDistance field. New street nodes within this distance to existing streets or nodes are snapped.
@return: Value of AdvancedSettingsSnappingDistance field. [float]
getAdvancedSettingsStreetToCrossingRatio
getAdvancedSettingsStreetToCrossingRatio(self):
Gets AdvancedSettingsStreetToCrossingRatio field. The approximate ratio between the number of major street and crossings. A high ratio leads to larger quarters.
@return: Value of AdvancedSettingsStreetToCrossingRatio field. [float]
getBasicSettingsLongLengthDeviation
getBasicSettingsLongLengthDeviation(self):
Gets BasicSettingsLongLengthDeviation field. Length deviation of long streets. New street lengths are between the average length minus this deviation and the average length plus this deviation.
@return: Value of BasicSettingsLongLengthDeviation field. [float]
getBasicSettingsLongLength
getBasicSettingsLongLength(self):
Gets BasicSettingsLongLength field. Average length of long streets (for both types major and minor).
@return: Value of BasicSettingsLongLength field. [float]
getBasicSettingsNumberOfStreets
getBasicSettingsNumberOfStreets(self):
Gets BasicSettingsNumberOfStreets field. Number of streets to be generated (due to intersections, more objects may emerge).
@return: Value of BasicSettingsNumberOfStreets field. [int]
getBasicSettingsPatternOfMajorStreets
getBasicSettingsPatternOfMajorStreets(self):
Gets BasicSettingsPatternOfMajorStreets field. Street pattern for major streets.
@return: Value of BasicSettingsPatternOfMajorStreets field. ["ORGANIC", "RASTER", "RADIAL"] [str]
getBasicSettingsPatternOfMinorStreets
getBasicSettingsPatternOfMinorStreets(self):
Gets BasicSettingsPatternOfMinorStreets field. Street pattern for minor streets.
@return: Value of BasicSettingsPatternOfMinorStreets field. ["ORGANIC", "RASTER", "RADIAL"] [str]
getBasicSettingsShortLengthDeviation
getBasicSettingsShortLengthDeviation(self):
Gets BasicSettingsShortLengthDeviation field. Length deviation of short streets. New street lengths are between the average length minus this deviation and the average length plus this deviation.
@return: Value of BasicSettingsShortLengthDeviation field. [float]
getBasicSettingsShortLength
getBasicSettingsShortLength(self):
Gets BasicSettingsShortLength field. Average length of short streets (for both types major and minor).
@return: Value of BasicSettingsShortLength field. [float]
getEnvironmentSettingsAdaptionAngle
getEnvironmentSettingsAdaptionAngle(self):
Gets EnvironmentSettingsAdaptionAngle field. The maximal angle a street is adapted towards the left or right side.
@return: Value of EnvironmentSettingsAdaptionAngle field. [float]
getEnvironmentSettingsAdaptToElevation
getEnvironmentSettingsAdaptToElevation(self):
Gets EnvironmentSettingsAdaptToElevation field. If true streets adapt to terrain elevation.
@return: Value of EnvironmentSettingsAdaptToElevation field. [True/False]
getEnvironmentSettingsCriticalSlope
getEnvironmentSettingsCriticalSlope(self):
Gets EnvironmentSettingsCriticalSlope field. Streets with slopes higher than this critical slope (in degrees) adapt to elevation.
@return: Value of EnvironmentSettingsCriticalSlope field. [float]
getEnvironmentSettingsHeightmap
getEnvironmentSettingsHeightmap(self):
Gets EnvironmentSettingsHeightmap field. The heightmap used for the adaption to elevation.
@deprecated: Only for legacy scripts, use getEnvironmentSettingsHeightmapLayer instead.
@return: Value of EnvironmentSettingsHeightmap field. [str]
getEnvironmentSettingsHeightmapLayer
getEnvironmentSettingsHeightmapLayer(self):
Gets EnvironmentSettingsHeightmapLayer field. The heightmap used for the adaption to elevation.
@return: Value of EnvironmentSettingsHeightmapLayer field. [str]
getEnvironmentSettingsMaximalSlope
getEnvironmentSettingsMaximalSlope(self):
Gets EnvironmentSettingsMaximalSlope field. The maximal legal street slope (in degrees), new streets above this threshold are dismissed.
@return: Value of EnvironmentSettingsMaximalSlope field. [float]
getEnvironmentSettingsObstaclemap
getEnvironmentSettingsObstaclemap(self):
Gets EnvironmentSettingsObstaclemap field. The obstaclemap which defines the environment obstacles.
@deprecated: Only for legacy scripts, use getEnvironmentSettingsObstaclemapLayer instead.
@return: Value of EnvironmentSettingsObstaclemap field. [str]
getEnvironmentSettingsObstaclemapLayer
getEnvironmentSettingsObstaclemapLayer(self):
Gets EnvironmentSettingsObstaclemapLayer field. The obstaclemap which defines the environment obstacles.
@return: Value of EnvironmentSettingsObstaclemapLayer field. [str]
getPatternSpecificSettingsCityCenterXRadial
getPatternSpecificSettingsCityCenterXRadial(self):
Gets PatternSpecificSettingsCityCenterXRadial field. X-coordinate of city center of radial streets.
@return: Value of PatternSpecificSettingsCityCenterXRadial field. [float]
getPatternSpecificSettingsCityCenterZRadial
getPatternSpecificSettingsCityCenterZRadial(self):
Gets PatternSpecificSettingsCityCenterZRadial field. Z-coordinate of city center of radial streets.
@return: Value of PatternSpecificSettingsCityCenterZRadial field. [float]
getPatternSpecificSettingsMaxBendAngleOrganic
getPatternSpecificSettingsMaxBendAngleOrganic(self):
Gets PatternSpecificSettingsMaxBendAngleOrganic field. Maximal bend angle of organic streets.
@return: Value of PatternSpecificSettingsMaxBendAngleOrganic field. [float]
getPatternSpecificSettingsMaxBendAngleRadial
getPatternSpecificSettingsMaxBendAngleRadial(self):
Gets PatternSpecificSettingsMaxBendAngleRadial field. Maximale bend angle of radial streets.
@return: Value of PatternSpecificSettingsMaxBendAngleRadial field. [float]
getPatternSpecificSettingsStreetAlignmentRadial
getPatternSpecificSettingsStreetAlignmentRadial(self):
Gets PatternSpecificSettingsStreetAlignmentRadial field. Alignment of the long radial streets.
@return: Value of PatternSpecificSettingsStreetAlignmentRadial field. ["RADIAL", "CENTRIPETAL", "RANDOM"] [str]
getStreetWidthSettingsCalculateWidthUsingStreetIntegration
getStreetWidthSettingsCalculateWidthUsingStreetIntegration(self):
Gets StreetWidthSettingsCalculateWidthUsingStreetIntegration field. Calculate the street integration of the complete graph and use the result to set the street widths. The widths will be calculated to vary between the minimum and maximum major street lanes parameters.
@return: Value of StreetWidthSettingsCalculateWidthUsingStreetIntegration field. [True/False]
getStreetWidthSettingsMaximumNumberOfMajorStreetLanes
getStreetWidthSettingsMaximumNumberOfMajorStreetLanes(self):
Gets StreetWidthSettingsMaximumNumberOfMajorStreetLanes field. The number of lanes on the widest major street.
@return: Value of StreetWidthSettingsMaximumNumberOfMajorStreetLanes field. [int]
getStreetWidthSettingsMaximumNumberOfMinorStreetLanes
getStreetWidthSettingsMaximumNumberOfMinorStreetLanes(self):
Gets StreetWidthSettingsMaximumNumberOfMinorStreetLanes field. The number of lanes on the widest minor street.
@return: Value of StreetWidthSettingsMaximumNumberOfMinorStreetLanes field. [int]
getStreetWidthSettingsMaximumNumberOfStreetLanes
getStreetWidthSettingsMaximumNumberOfStreetLanes(self):
Gets StreetWidthSettingsMaximumNumberOfStreetLanes field. The minimum number of lanes on the streets.
@return: Value of StreetWidthSettingsMaximumNumberOfStreetLanes field. [int]
getStreetWidthSettingsMaximumSidewalkWidth
getStreetWidthSettingsMaximumSidewalkWidth(self):
Gets StreetWidthSettingsMaximumSidewalkWidth field. The maximum width of the sidewalks.
@return: Value of StreetWidthSettingsMaximumSidewalkWidth field. [float]
getStreetWidthSettingsMinimumNumberOfMajorStreetLanes
getStreetWidthSettingsMinimumNumberOfMajorStreetLanes(self):
Gets StreetWidthSettingsMinimumNumberOfMajorStreetLanes field. The number of lanes on the narrowest major street.
@return: Value of StreetWidthSettingsMinimumNumberOfMajorStreetLanes field. [int]
getStreetWidthSettingsMinimumNumberOfMinorStreetLanes
getStreetWidthSettingsMinimumNumberOfMinorStreetLanes(self):
Gets StreetWidthSettingsMinimumNumberOfMinorStreetLanes field. The number of lanes on the narrowest minor street.
@return: Value of StreetWidthSettingsMinimumNumberOfMinorStreetLanes field. [int]
getStreetWidthSettingsMinimumNumberOfStreetLanes
getStreetWidthSettingsMinimumNumberOfStreetLanes(self):
Gets StreetWidthSettingsMinimumNumberOfStreetLanes field. The maximum number of lanes on the streets.
@return: Value of StreetWidthSettingsMinimumNumberOfStreetLanes field. [int]
getStreetWidthSettingsMinimumSidewalkWidth
getStreetWidthSettingsMinimumSidewalkWidth(self):
Gets StreetWidthSettingsMinimumSidewalkWidth field. The minimum width of the sidewalks.
@return: Value of StreetWidthSettingsMinimumSidewalkWidth field. [float]
getStreetWidthSettingsSidewalkWidthDeviationOfMajorStreets
getStreetWidthSettingsSidewalkWidthDeviationOfMajorStreets(self):
Gets StreetWidthSettingsSidewalkWidthDeviationOfMajorStreets field. Width deviation of major street sidewalks.
@return: Value of StreetWidthSettingsSidewalkWidthDeviationOfMajorStreets field. [float]
getStreetWidthSettingsSidewalkWidthDeviationOfMinorStreets
getStreetWidthSettingsSidewalkWidthDeviationOfMinorStreets(self):
Gets StreetWidthSettingsSidewalkWidthDeviationOfMinorStreets field. Width deviation of minor street sidewalks.
@return: Value of StreetWidthSettingsSidewalkWidthDeviationOfMinorStreets field. [float]
getStreetWidthSettingsSidewalkWidthOfMajorStreets
getStreetWidthSettingsSidewalkWidthOfMajorStreets(self):
Gets StreetWidthSettingsSidewalkWidthOfMajorStreets field. Average width of major street sidewalks.
@return: Value of StreetWidthSettingsSidewalkWidthOfMajorStreets field. [float]
getStreetWidthSettingsSidewalkWidthOfMinorStreets
getStreetWidthSettingsSidewalkWidthOfMinorStreets(self):
Gets StreetWidthSettingsSidewalkWidthOfMinorStreets field. Average width of minor street sidewalks.
@return: Value of StreetWidthSettingsSidewalkWidthOfMinorStreets field. [float]
setAdvancedSettingsAngleOffsetOfMajorStreets
setAdvancedSettingsAngleOffsetOfMajorStreets(self, floatValue):
Sets AdvancedSettingsAngleOffsetOfMajorStreets field. Offset angle which is added to every major street before creation (e.g. to create spiral street patterns).
@param floatValue: the new value. [float]
setAdvancedSettingsAngleOffsetOfMinorStreets
setAdvancedSettingsAngleOffsetOfMinorStreets(self, floatValue):
Sets AdvancedSettingsAngleOffsetOfMinorStreets field. Offset angle which is added to every minor street before creation (e.g. to create spiral street patterns).
@param floatValue: the new value. [float]
setAdvancedSettingsDevelopmentCenterPreference
setAdvancedSettingsDevelopmentCenterPreference(self, intValue):
Sets AdvancedSettingsDevelopmentCenterPreference field. Development center sampling preference. Corresponds to the number of samples before taking the node which is the nearest to the center.
@param intValue: the new value. [int]
setAdvancedSettingsMinimalAngle
setAdvancedSettingsMinimalAngle(self, floatValue):
Sets AdvancedSettingsMinimalAngle field. If a new street intersects/snaps with the existing streetnetwork and the in-between angle is below this threshold, the new street is dismissed.
@param floatValue: the new value. [float]
setAdvancedSettingsSnappingDistance
setAdvancedSettingsSnappingDistance(self, floatValue):
Sets AdvancedSettingsSnappingDistance field. New street nodes within this distance to existing streets or nodes are snapped.
@param floatValue: the new value. [float]
setAdvancedSettingsStreetToCrossingRatio
setAdvancedSettingsStreetToCrossingRatio(self, floatValue):
Sets AdvancedSettingsStreetToCrossingRatio field. The approximate ratio between the number of major street and crossings. A high ratio leads to larger quarters.
@param floatValue: the new value. [float]
setBasicSettingsLongLengthDeviation
setBasicSettingsLongLengthDeviation(self, floatValue):
Sets BasicSettingsLongLengthDeviation field. Length deviation of long streets. New street lengths are between the average length minus this deviation and the average length plus this deviation.
@param floatValue: the new value. [float]
setBasicSettingsLongLength
setBasicSettingsLongLength(self, floatValue):
Sets BasicSettingsLongLength field. Average length of long streets (for both types major and minor).
@param floatValue: the new value. [float]
setBasicSettingsNumberOfStreets
setBasicSettingsNumberOfStreets(self, intValue):
Sets BasicSettingsNumberOfStreets field. Number of streets to be generated (due to intersections, more objects may emerge).
@param intValue: the new value. [int]
setBasicSettingsPatternOfMajorStreets
setBasicSettingsPatternOfMajorStreets(self, enumValue):
Sets BasicSettingsPatternOfMajorStreets field. Street pattern for major streets.
@param enumValue: the new value ["ORGANIC", "RASTER", "RADIAL"]. [str]
setBasicSettingsPatternOfMinorStreets
setBasicSettingsPatternOfMinorStreets(self, enumValue):
Sets BasicSettingsPatternOfMinorStreets field. Street pattern for minor streets.
@param enumValue: the new value ["ORGANIC", "RASTER", "RADIAL"]. [str]
setBasicSettingsShortLengthDeviation
setBasicSettingsShortLengthDeviation(self, floatValue):
Sets BasicSettingsShortLengthDeviation field. Length deviation of short streets. New street lengths are between the average length minus this deviation and the average length plus this deviation.
@param floatValue: the new value. [float]
setBasicSettingsShortLength
setBasicSettingsShortLength(self, floatValue):
Sets BasicSettingsShortLength field. Average length of short streets (for both types major and minor).
@param floatValue: the new value. [float]
setEnvironmentSettingsAdaptionAngle
setEnvironmentSettingsAdaptionAngle(self, floatValue):
Sets EnvironmentSettingsAdaptionAngle field. The maximal angle a street is adapted towards the left or right side.
@param floatValue: the new value. [float]
setEnvironmentSettingsAdaptToElevation
setEnvironmentSettingsAdaptToElevation(self, booleanValue):
Sets EnvironmentSettingsAdaptToElevation field. If true streets adapt to terrain elevation.
@param booleanValue: the new value. [True/False]
setEnvironmentSettingsCriticalSlope
setEnvironmentSettingsCriticalSlope(self, floatValue):
Sets EnvironmentSettingsCriticalSlope field. Streets with slopes higher than this critical slope (in degrees) adapt to elevation.
@param floatValue: the new value. [float]
setEnvironmentSettingsHeightmap
setEnvironmentSettingsHeightmap(self, stringValue):
Sets EnvironmentSettingsHeightmap field. The heightmap used for the adaption to elevation.
@deprecated: Only for legacy scripts, use setEnvironmentSettingsHeightmapLayer instead.
@param stringValue: the new value. [str]
setEnvironmentSettingsHeightmapLayer
setEnvironmentSettingsHeightmapLayer(self, stringValue):
Sets EnvironmentSettingsHeightmapLayer field. The heightmap used for the adaption to elevation.
@param stringValue: the new value. [str]
setEnvironmentSettingsMaximalSlope
setEnvironmentSettingsMaximalSlope(self, floatValue):
Sets EnvironmentSettingsMaximalSlope field. The maximal legal street slope (in degrees), new streets above this threshold are dismissed.
@param floatValue: the new value. [float]
setEnvironmentSettingsObstaclemap
setEnvironmentSettingsObstaclemap(self, stringValue):
Sets EnvironmentSettingsObstaclemap field. The obstaclemap which defines the environment obstacles.
@deprecated: Only for legacy scripts, use getEnvironmentSettingsObstaclemapLayer instead.
@param stringValue: the new value. [str]
setEnvironmentSettingsObstaclemapLayer
setEnvironmentSettingsObstaclemapLayer(self, stringValue):
Sets EnvironmentSettingsObstaclemapLayer field. The obstaclemap which defines the environment obstacles.
@param stringValue: the new value. [str]
setPatternSpecificSettingsCityCenterXRadial
setPatternSpecificSettingsCityCenterXRadial(self, floatValue):
Sets PatternSpecificSettingsCityCenterXRadial field. X-coordinate of city center of radial streets.
@param floatValue: the new value. [float]
setPatternSpecificSettingsCityCenterZRadial
setPatternSpecificSettingsCityCenterZRadial(self, floatValue):
Sets PatternSpecificSettingsCityCenterZRadial field. Z-coordinate of city center of radial streets.
@param floatValue: the new value. [float]
setPatternSpecificSettingsMaxBendAngleOrganic
setPatternSpecificSettingsMaxBendAngleOrganic(self, floatValue):
Sets PatternSpecificSettingsMaxBendAngleOrganic field. Maximal bend angle of organic streets.
@param floatValue: the new value. [float]
setPatternSpecificSettingsMaxBendAngleRadial
setPatternSpecificSettingsMaxBendAngleRadial(self, floatValue):
Sets PatternSpecificSettingsMaxBendAngleRadial field. Maximale bend angle of radial streets.
@param floatValue: the new value. [float]
setPatternSpecificSettingsStreetAlignmentRadial
setPatternSpecificSettingsStreetAlignmentRadial(self, enumValue):
Sets PatternSpecificSettingsStreetAlignmentRadial field. Alignment of the long radial streets.
@param enumValue: the new value ["RADIAL", "CENTRIPETAL", "RANDOM"]. [str]
setStreetWidthSettingsCalculateWidthUsingStreetIntegration
setStreetWidthSettingsCalculateWidthUsingStreetIntegration(self, booleanValue):
Sets StreetWidthSettingsCalculateWidthUsingStreetIntegration field. Calculate the street integration of the complete graph and use the result to set the street widths. The widths will be calculated to vary between the minimum and maximum major street lanes parameters.
@param booleanValue: the new value. [True/False]
setStreetWidthSettingsMaximumNumberOfMajorStreetLanes
setStreetWidthSettingsMaximumNumberOfMajorStreetLanes(self, intValue):
Sets StreetWidthSettingsMaximumNumberOfMajorStreetLanes field. The number of lanes on the widest major street.
@param intValue: the new value. [int]
setStreetWidthSettingsMaximumNumberOfMinorStreetLanes
setStreetWidthSettingsMaximumNumberOfMinorStreetLanes(self, intValue):
Sets StreetWidthSettingsMaximumNumberOfMinorStreetLanes field. The number of lanes on the widest minor street.
@param intValue: the new value. [int]
setStreetWidthSettingsMaximumNumberOfStreetLanes
setStreetWidthSettingsMaximumNumberOfStreetLanes(self, intValue):
Sets StreetWidthSettingsMaximumNumberOfStreetLanes field. The minimum number of lanes on the streets.
@param intValue: the new value. [int]
setStreetWidthSettingsMaximumSidewalkWidth
setStreetWidthSettingsMaximumSidewalkWidth(self, floatValue):
Sets StreetWidthSettingsMaximumSidewalkWidth field. The maximum width of the sidewalks.
@param floatValue: the new value. [float]
setStreetWidthSettingsMinimumNumberOfMajorStreetLanes
setStreetWidthSettingsMinimumNumberOfMajorStreetLanes(self, intValue):
Sets StreetWidthSettingsMinimumNumberOfMajorStreetLanes field. The number of lanes on the narrowest major street.
@param intValue: the new value. [int]
setStreetWidthSettingsMinimumNumberOfMinorStreetLanes
setStreetWidthSettingsMinimumNumberOfMinorStreetLanes(self, intValue):
Sets StreetWidthSettingsMinimumNumberOfMinorStreetLanes field. The number of lanes on the narrowest minor street.
@param intValue: the new value. [int]
setStreetWidthSettingsMinimumNumberOfStreetLanes
setStreetWidthSettingsMinimumNumberOfStreetLanes(self, intValue):
Sets StreetWidthSettingsMinimumNumberOfStreetLanes field. The maximum number of lanes on the streets.
@param intValue: the new value. [int]
setStreetWidthSettingsMinimumSidewalkWidth
setStreetWidthSettingsMinimumSidewalkWidth(self, floatValue):
Sets StreetWidthSettingsMinimumSidewalkWidth field. The minimum width of the sidewalks.
@param floatValue: the new value. [float]
setStreetWidthSettingsSidewalkWidthDeviationOfMajorStreets
setStreetWidthSettingsSidewalkWidthDeviationOfMajorStreets(self, floatValue):
Sets StreetWidthSettingsSidewalkWidthDeviationOfMajorStreets field. Width deviation of major street sidewalks.
@param floatValue: the new value. [float]
setStreetWidthSettingsSidewalkWidthDeviationOfMinorStreets
setStreetWidthSettingsSidewalkWidthDeviationOfMinorStreets(self, floatValue):
Sets StreetWidthSettingsSidewalkWidthDeviationOfMinorStreets field. Width deviation of minor street sidewalks.
@param floatValue: the new value. [float]
setStreetWidthSettingsSidewalkWidthOfMajorStreets
setStreetWidthSettingsSidewalkWidthOfMajorStreets(self, floatValue):
Sets StreetWidthSettingsSidewalkWidthOfMajorStreets field. Average width of major street sidewalks.
@param floatValue: the new value. [float]
setStreetWidthSettingsSidewalkWidthOfMinorStreets
setStreetWidthSettingsSidewalkWidthOfMinorStreets(self, floatValue):
Sets StreetWidthSettingsSidewalkWidthOfMinorStreets field. Average width of minor street sidewalks.
@param floatValue: the new value. [float]
Constants
This class defines the following constants:
CENTRIPETAL = 'CENTRIPETAL'
ORGANIC = 'ORGANIC'
RADIAL = 'RADIAL'
RANDOM = 'RANDOM'
RASTER = 'RASTER'