API Reference > imodeljs-common > Symbology > GeometryParams > fillDisplay fillDisplay fillDisplay: undefined | FillDisplay Optional fill specification that determines when and if a region interior will display using GeometryParams.gradient, GeometryParams.backgroundFill, or GeometryParams.fillColor in that order of preference. Fill only applies to RenderMode.Wireframe views. In a RenderMode.SmoothShade or RenderMode.SolidFill view, regions will always display as surfaces preferring GeometryParams.fillColor when present over GeometryParams.lineColor. Default is FillDisplay.Never. Defined in core/common/src/GeometryParams.ts Line 93 Last Updated: 12 June, 2024