MapGuide RFC 16 - Elevation and Extrusion Support for KML

This page contains a change request (RFC) for the MapGuide Open Source project. More MapGuide RFCs can be found on the RFCs page.

Status

RFC Template Version	(1.0)
Submission Date	(Date/Time submitted)
Last Modified	Chris ClaydonTimestamp
Author	Chris Claydon
RFC Status	draft
Implementation Status	pending
Proposed Milestone	1.2
Assigned PSC guide(s)
Voting History	(vote date)
+1
+0
-0
-1

Overview

The purpose of this RFC is to allow MapGuide users to configure elevation and extrusion parameters in a layer definition, and to use those settings to extrude features vertically in the KML generated for consumption by Google Earth. This provides a highly compelling way to visualize spatial data that contains a vertical component.

Motivation

MapGuide currently supports 2D representation of spatial data. However, many spatial data sets contain height information for the features they contain, giving the potential for 2.5D representation. This RFC describes how the MapGuide Layer Definition schema can be extended to specify expressions to be used to calculate a base elevation and extrusion size. Support for 2.5D would initially be implemented by the KML service, allowing visualization of solid objects in Google Earth. An example of the potential output is shown below:

Proposed Solution

This is a more detailed description of the actual changes desired. The contents of this section will vary based on the target of the RFC, be it a technical change, website change, or process change. For example, for a technical change, items such as files, XML schema changes, and API chances would be identified. For a process change, the new process would be laid out in detail. For a website change, the files affected would be listed.

Implications

This section allows discussion of the repercussions of the change, such as whether there will be any breakage in backwards compatibility, if documentation will need to be updated, etc.

Test Plan

How the proposed change will be tested, if applicable. New unit tests should be detailed here???

Funding/Resources

This section will confirm that the proposed feature has enough support to proceed. This would typically mean that the entity making the changes would put forward the RFC, but a non-developer could act as an RFC author if they are sure they have the funding to cover the change.