Is is possible to make a map tile package of imagery that has some areas of the imagery masked out?

[Jacob_Coble]

I am using ArcGIS Pro 3.4. I am wanting to create a map tile package of imagery where certain areas of the tile package would be masked out. For example, I have a Mosaic Dataset of a county. The source imagery is in tiles and the imagery in the mosaic dataset extends a bit outside of the county boundary. What I want to do is make a map tile package of the imagery where the imagery is masked by the county boundary. That way, any part of the imagery beyond the county boundary would be transparent. This is necessary so that the imagery won't interfere with other imagery outside of the county boundary. 

I see that the geoprocessing tool Create Map Tile Package of Imagery has an Environment setting for Mask. You should be able to include a raster or a vector layer here for a mask. I tried using a polygon feature class of the county boundary for a mask. But when I created the map tile package of imagery, no areas of the imagery in the map tile package were masked out. Maybe there are other settings that have to be a certain way for the masking to work? Perhaps something to do with the Cell Size? I don't know. I appreciate any suggestions. Thanks!

[Bandlytics]

Hi Jacob. One thing to note is that the tool you referenced seems to be a custom GP tool created by someone else and isn't part of our core tools. But what you are trying to achieve is possible. See steps below:

Step 1: Create a feature class containing the area of interest (seems you already have this). If the feature class includes multiple polygons, ensure it is multipart prior to proceeding with subsequent steps.

Step 2: Compare the OBJECTID value in your feature class and the mosaic dataset boundary. If they differ, add a new field with your preferred name to your feature class and match its value to the mosaic dataset boundary's OBJECTID.

Step 3: Enable “Clip to Boundary Property” in Mosaic Dataset

• Navigate to the Catalog pane and to the location of your mosaic dataset
• Right-click the mosaic dataset, Click Properties, then Defaults and under Image Properties, check the box beside Always clip the mosaic dataset to its boundary
• Click OK

Step 4: Run “Import Mosaic Dataset Geometry” to clip Mosaic Dataset. Bring up the Import Mosaic Dataset Geometry GP tool in ArcGIS Pro:

• For Mosaic Dataset, select your Mosaic Dataset
• For Target Feature Class, select Boundary from the list of options
• For Target Join Field, select OBJECTID from the list of options
• For Input Feature Class, select the multipart feature you created in step 1
• For Input Join Field, select OBJECTID from the list of options (or if you created a new field in step 2, use that field name instead).
• Click Run
• Your mosaic dataset should now only show imagery within your area of interest. If it doesn’t, remove it from the map and re-add it to see the update

Step 5: Run the Create Map Tile Package GP tool