Tips for authoring globe services

When designing a globe document to be published as a globe service, consider the following tips for optimum performance:

Remove globe service layers, including the default ArcGIS Online layers

Embedding a globe service within another globe service is generally detrimental to performance and can also cause problems with out-of-date caches. If you want another globe service to participate in your end-client application, you should connect to that service directly in the application.

Be especially aware that the default globe in ArcGlobe contains globe service layers from ArcGIS Online services. You should remove these default layers before publishing the globe service.

If you still want viewers to see the ArcGIS Online content along with some of your own layers, you should publish your service without the ArcGIS Online layers. Then, create either an ArcGlobe document, a 3D ArcReader document, or an ArcGIS Explorer map and add the following layers:

You can post this document on a Web page or in a shared location. This workflow ensures that clients retrieve each globe service in the most efficient way.

Note: If you'll be publishing many globe services, you might want to change your ArcGlobe preferences so that the default globe does not start with ArcGIS Online layers.

Set scale-dependent rendering for layers

Set distance ranges on your layers to ensure that unneeded layers do not draw when the globe is zoomed out/in. Data-intensive or highly detailed layers may be more appropriate only when the globe is zoomed in to a larger scale. Use the Globe General tab of the Layer Properties page to set distance ranges.

Simplify layer symbology

Complex symbols take longer to draw. Use simple line and fill symbols where possible, avoiding symbology that contains multiple layers, complicated dash patterns, or outlines.

Use raster compression

The Cache tab of the Layer Properties dialog box contains options for raster compression. ArcGlobe offers two types of lossy spatial compressions, JPEG and DXT. Using compression on image data reduces cache storage space by spatially averaging the distribution of colors in an image.

The JPEG compression format reduces the size of the cache generated by compressing the data tiles in JPEG format. ArcGlobe gives you control over what degree of compression to use. This is exposed as a relative quality of the image data. The default, a quality of 75 percent, usually gives acceptable results and is recommended.

DXT compression is another lossy image compression format that is directly supported by the driver of your graphics card hardware. DXT-compressed tiles are optimal for high-resolution imagery data. DXT-compressed data tiles improve visualization performance, as their size does not grow when loaded into memory, allowing the client to have a smaller memory footprint. However, the tile size of DXT-compressed data on disk can be significantly larger than JPEG-compressed tiles, depending on the JPEG quality selected (usually the DXT-compressed data is 8–12 times larger than the corresponding JPEG-compressed tiles).

Note that some server class machines (especially older ones) might not have a graphics card that supports hardware-based compression of DXT tiles. In this case, ArcGlobe and ArcGIS Server are equipped with a software-based emulation that will allow you to compress data caches into DXT-compressed tiles.

Compress the pixel value range to 16 bits

Compressing the pixel value range to 16 bits is a default setting that limits raster displays to 65,536 colors. Usage of this option is recommended. Only use 24 bits of color resolution if high-fidelity imagery is required.

Use this same option to compress the elevation range of a raster surface to 16 bits. Uncheck this option to use 32 bits of range, which is useful only if your elevation source has submeter vertical accuracy.

Increase the minimum cell size of raster layers

If your raster data resolution is very high, you can progressively increase the minimum cell size, thereby decreasing the size of the data cache. Set the minimum cell size at the highest value that is appropriate for your data and the needs of your audience.

Remove unused layers

Verify that your globe document is free of layers that are not intended to be part of the globe service.

Verify ArcGIS Server permissions

Your ArcGIS Server SOC account should have at least Read permissions to any globe documents and data that you access through the globe service.

Also, there may be scenarios where you publish a 2D map service as a layer in a globe service (you might do this if you intended to create a 3D cache from a 2D cache). If this map service is accessed through a local, or LAN, connection, your SOC account must be a member of the agsusers group on the machine hosting the map service.

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