First, you create the model decoder that decodes the custom elevation format. Once you have the model decoder, you must register it as a service. To learn both how to create the decoder and register it as a service, see Support a custom raster format.

The semantics of the raster data must indicate that it contains elevation data.

The example in the Support a custom raster format article shows how to indicate the presence of elevation data by using the ALcdBandMeasurementSemantics class, an extension of ALcdBandSemantics.