There are two cases where a command is used for refreshing the link between Woodwork for Inventor material data and model representation:
2. In some cases, an appearance assigned to faces disappears after performing a Joint Sculpt operation. The material refresh command re-assigns a required appearance to these faces.
3. An inexperienced user may sometimes rotate the face grain directions assigned to Woodwork for Inventor parts without using part or cover grain adjustment mechanism provided in Woodwork for Inventor. In this case, a link between the image and the data entered in Woodwork for Inventor is damaged. The material refresh command restores grain directions, taking into account the assignment of Woodwork for Inventor materials.
To open the command, go to:
Woodwork Design –> Material –> Refresh 
After starting the command, a progress indicator will appear showing the percentage of command completion. The end of the command will be indicated by the absence of the indicator. Colour refresh is performed using the active replacement configuration data.
Note: In case of large-scale models or when restoring lost links of the transferred Autodesk Inventor material and appearance database, the process may take some time. In such cases, it is recommended that you perform the Refresh command in individual sub-assemblies. Also, before starting the Refresh command, you need to use the Rebuild All command.
In case of an assembly, it is recommended that before you start the refresh command, you Suppress all sheet metal type parts. It is best to use the refresh command for sheet metal parts by opening it in a flat pattern. If a part has an Embossed assembly element which consists of projected text geometry, then before you start the refresh command, it is recommended that you Suppress this assembly element. After running the refresh command, you can Unsuppressed the above-mentioned element.