# ![Lightmap UVs icon](images/icons/Object_LightmapUVs.png) Lightmap UVs

Use the __Lightmap UVs__ action to manually generate any missing lightmap UVs. This works on each Mesh in every open scene that is missing lightmap UVs.

> **Tip:** You can edit lightmap generation parameters for specific objects in the [ProBuilderMesh](ProBuilderMesh.md) component on ProBuilder objects. You can also modify the defaults on the [ProBuilder Preferences](preferences.md#autouvs) window.

There is one option for this action which you can access like any other [toolbar option](toolbar.md#pb_options). You can also access it using the menu (**Tools** > **ProBuilder** > **Editors** > **Open Lightmap UV Editor**), because it appears on the [Lightmap UV Editor](lightmap-uv.md) window.