In this CAD model, the inlets are the outer openings in Z-direction. To define these openings as inlet, switch to the 2D-view by clicking the icon. Under the Camera tab of the view controls panel, choose Direction Z as axis and set Slice to 1.
Click the icon in the toolbar to edit voxels. In the opening Voxel Selection dialog shown on the right, choose Flood-Fill Component Plane as Component Mode. Select 06 Oil as New Material ID and write Inlet into the Set Material Information edit box.
With the Voxel Selection dialog still open, click anywhere inside the inlet planes in the Visualization area of the GeoDict GUI. To select all the 16 inlet planes, hold CTRL + click in each plane. This action marks these voxels in the inlet and now their Position coordinates appear in the Selected Voxels field.
Then click Run to have the Flood-Fill Component Plane option fill each of the slices with the New Material ID (cyan, ID 06). The inlet openings are now assigned to Material ID 06:
Now, define the outlet plane following the same steps. To do so, click Clear Selection, and select now a single voxel in the central outlet plane.
The component mode remains as Flood-filled Component Plane. Select 07 Oil as New Material IDand enter Outlet in the Set Material Information edit box.
Click Run to assign the outlet plane to Material ID 07.