API Reference > imodeljs-common > Rendering > RenderMaterial > RenderMaterial.Params > alpha alpha Accessor A value from 0.0 (fully-transparent) to 1.0 (fully-opaque) controlling the transparency of surfaces to which this material is applied; or undefined if this material does not override surface transparency. alpha: undefined | number Returns - undefined | number Setter A value from 0.0 (fully-transparent) to 1.0 (fully-opaque) controlling the transparency of surfaces to which this material is applied; or undefined if this material does not override surface transparency. alpha(alpha: undefined | number): void Parameter Type Description alpha undefined | number Returns - void Defined in core/common/src/RenderMaterial.ts Line 74 Last Updated: 12 June, 2024