Modeler itself doesn't use Houdini's radial menus. But at the same time, you can still use them during the modeling process. Due to the fact that the Modeler's hotkeys overlap with Houdini's hotkeys, you need to ensure that the hotkey for the radial menu is not being used in Modeler. If there is a conflict, you need to either change the corresponding hotkey in Houdini or in the Modeler hotkey editor. For example, if you want to show menu with the X key, which by default in Houdini assigned to Snapping menu, then you need to reassign this key in the Modeler’s hotkey editor. Open the hotkey editor and in the filter field enter X. After finding the tool with this key, reassign it by double-clicking.
To add Modeler tools to the radial menus, use this script, replacing “ToolName” with the name of the required tool:
import modeler.tools
modeler.tools.ToolName()