When to use a group layer cache

Group layers in ArcGlobe can have their own cache. The group layer cache can be instead of the child caches (rasterizing the group layer) or as well as the child caches (merging the child caches). In both cases, the group layer's cache will represent a consolidated view of the child layers.

Group layer caches can improve the performance of ArcGlobe by reducing the number of disk caches ArcGlobe has to render to the screen. Like all cache types, the performance benefits for a group layer cache become evident when areas are revisited.

There are several factors you should consider before using a group layer cache in ArcGlobe. These factors include: how interactive you require the child layers to be, what display options are being used for the child layers, and what type of data is being displayed. Once you have determined that a group layer cache is a good option, you must then decide which type of cache consolidation is best for this group layer.

Should your group layer use a cache?

The following series of questions will help you determine if your group layer can benefit from having a cache.

Have you stopped interacting with the appearance of the group layer?

This includes altering child layer symbology, visibility, transparency, drawing order, or visible scale ranges.

• No.

  The group layer should not use a cache.

• Yes.

  Continue to the next question.

Are there two or more rasterized layers in the group layer?

This includes image layers and rasterized vector layers.

• No.

  The group layer should not use a cache.

• Yes.

  Continue to the next question.

Are you willing to create and manage a cache for the group layer?

The group layer will use disk space to store its cache and may require maintenance in the future.

• No.

  The group layer should not use a cache.

• Yes.

  A cache can help improve the performance of your group layer and should be enabled.

Which type of cache is best for your group layer?

Once you have determined your group layer will benefit from having a cache, the following series of questions will help you identify the best consolidation option to use.

Are any child layers not rasterized and draped on the surface of the globe?

For example, are any child layers floating layers, 3D vector layers, or elevation layers?

• Yes.

  You should use the merging caches option for the group layer cache.

• No.

  Continue to the next question.

Does your group layer contain a layer from Globe Server?

• Yes.

  You should use the merging caches option for the group layer cache.

• No.

  Continue to the next question.

Are your child layers already fully cached?

• Yes.

  You should use the merging caches option for the group layer cache.

• No.

  Continue to the next question.

Are all child layers image layers?

• Yes.

  You should use the merging caches option for the group layer cache.

• No.

  You should use the rasterizing group layer option for the group layer cache.

Example workflows

Below are three common workflows for creating group layers in ArcGlobe and the recommended option for the group layer cache.

1. Creating a group layer of displayed layers listed by type in the table of contents.
   • Open ArcGlobe and develop a 3D view.
   • Click List ByType on the table of contents so you can see layers categorized by their role.
   • Select a set of displayed layers.

     For example, mostly draped rasterized vector layers and a few floating layers.

   • Right-click the selection and click Group.

     The new group layer is displayed only when theList Including Group Layers button is active in the table of contents.

   Recommendation: Create a group layer cache with the merge child layers option using the Group Cache Settings dialog box (right-click the New Group Layer). The new display cache layer for the merged child layers is added to the List By Type list of layers in the table of contents.
   Tip:

   • Hold down either the SHIFT or CTRL key to multiple select layers.
2. Creating a mixed type group layer for organizational purposes (only visible under List Including Group Layers sorting option on the table of contents)
   • Open ArcGlobe and develop a 3D view.
   • Click List ByType on the table of contents so you can see layers categorized by their role.
   • Select a set of mixed layers.

     For example, some floating layers, some draped layers, and some elevation layers.

   • Right-click the selection and click Group.
   • Click the List Including Group Layers button to toggle the table of contents organization. Verify the group layer was added to the list.
   Recommendation: Do not create a group layer cache.
   Tip:

   • Hold down either the SHIFT or CTRL key to multiple select layers.
   • You can open the Group Cache Settings dialog box from this list by right-clicking the New Group Layer.

3. Copying a group layer from ArcMap
   • Open ArcMap and create a group layer.
   • Right-click the group layer in the ArcMap table of contents and click Copy.
   • Open ArcGlobe and click the List Including Group Layers button.
   • Right-click Globe Layers in the table of contents and click Paste Layer(s).
   Recommendation: Create a group layer cache with the rasterizing option using the Group Cache Settings dialog box by right-clicking the New Group Layer.