Here are the classes, structs, unions and interfaces with brief descriptions:

[detail level 123]

►NGradientSignal
►NImageCreatorUtils
CPaintableImageAssetHelperBase
CPaintableImageAssetHelper
CConstantGradientConfig
CConstantGradientComponent
CDitherGradientConfig
CDitherGradientComponent
CGradientSurfaceDataConfig
CGradientSurfaceDataComponent
CGradientTransformConfig
CGradientTransformComponent
CJsonImageGradientConfigSerializer
CImageGradientConfig
CImageGradientComponent
CImageTileBuffer
CImageGradientSizeData	Tracks all of the data related to the image gradient size, including its transform
CPaintStrokeData	Tracks all of the data that's specific to a paint stroke
CModifiedImageRegion
CImageGradientModifier	Top-level class that handles all of the actual image modification calculations for a paintbrush
CInvertGradientConfig
CInvertGradientComponent
CLevelsGradientConfig
CLevelsGradientComponent
CMixedGradientLayer
CMixedGradientConfig
CMixedGradientComponent
CPerlinGradientConfig
CPerlinGradientComponent
CPosterizeGradientConfig
CPosterizeGradientComponent
CRandomGradientConfig
CRandomGradientComponent
CReferenceGradientConfig
CReferenceGradientComponent
CShapeAreaFalloffGradientConfig
CShapeAreaFalloffGradientComponent
CSmoothStepGradientConfig
CSmoothStepGradientComponent
CSurfaceAltitudeGradientConfig
CSurfaceAltitudeGradientComponent
CSurfaceMaskGradientConfig
CSurfaceMaskGradientComponent
CSurfaceSlopeGradientConfig
CSurfaceSlopeGradientComponent
CThresholdGradientConfig
CThresholdGradientComponent
CConstantGradientRequests
CDitherGradientRequests
►CGradientPreviewContextRequests
CBusHandlerOrderCompare
CGradientPreviewRequests
CGradientSampleParams
CGradientRequests
CGradientSurfaceDataRequests
CGradientTransformModifierRequests
CGradientTransformRequests
►CGradientTransformNotifications
CConnectionPolicy	Connection policy that auto-calls OnGradientTransformChanged on connection with the current GradientTransform data
CImageGradientModifications
CImageGradientModificationNotifications	EBus that notifies about the current state of Image Gradient modifications
CImageGradientRequests
CInvertGradientRequests
CLevelsGradientRequests
CMixedGradientRequests
CPerlinGradientRequests
CPosterizeGradientRequests
CRandomGradientRequests
CReferenceGradientRequests
CSectorDataRequests
CSectorDataNotifications
CShapeAreaFalloffGradientRequests
CSmoothStepGradientRequests
CSmoothStepRequests
CSurfaceAltitudeGradientRequests
CSurfaceMaskGradientRequests
CSurfaceSlopeGradientRequests
CThresholdGradientRequests
CGradientBakerConfig
CBakeImageJob
CEditorGradientBakerComponent
CGradientBakerRequests
CHasGradientSampler
CHasGradientSampler< T, decltype((void) T::m_gradientSampler, 0)>
CHasCustomSetSamplerOwner
CEditorGradientComponentBase
CGradientImageCreatorRequests
CEditorGradientPreviewUpdateJob
CEditorGradientPreviewRenderer
CGradientPreviewer
CGradientSampler
CGradientTransform
CPerlinImprovedNoise
CSmoothStep
CEditorConstantGradientComponent
CEditorDitherGradientComponent
CEditorGradientSurfaceDataComponent
CEditorGradientTransformComponent
CEditorImageGradientComponent
CEditorImageGradientComponentMode
CEditorInvertGradientComponent
CEditorLevelsGradientComponent
CHasCustomSetSamplerOwner< MixedGradientConfig >
CEditorMixedGradientComponent
CEditorPerlinGradientComponent
CEditorPosterizeGradientComponent
CEditorRandomGradientComponent
CEditorReferenceGradientComponent
CEditorShapeAreaFalloffGradientComponent
CEditorSmoothStepGradientComponent
CSupportedImageAssetPickerDialog
CStreamingImagePropertyAssetCtrl
CStreamingImagePropertyHandler
CEditorSurfaceAltitudeGradientComponent
CEditorSurfaceMaskGradientComponent
CEditorSurfaceSlopeGradientComponent
CEditorThresholdGradientComponent
CGradientSignalEditorModule
CGradientSignalEditorSystemComponent
CGradientSignalModule
CGradientSignalSystemComponent
CGradientPreviewDataWidget
CGradientPreviewDataWidgetHandler
CGradientPreviewWidget
►NLmbrCentral
CEditorWrappedComponentBase