[ros-users] Standardization of mapping interfaces

[Armin Hornung]

On 2012-10-04 19:49, Stéphane Magnenat wrote:
> Hello,
>
> I am working on the release of our modular ICP pipeline [1] (2D and 
> 3D), which provides a mapping-style interface. While doing so, I 
> realized that some features are commonly available in mapping 
> packages, like getting the latest version of the map or reseting it. 
> However, I have not find any standard to do so. Worst, while for 2D 
> there is a message nav_msgs::GetMap, there is no standard equivalent 
> in 3D. To allow easy interoperability between packages doing the same 
> thing, it is important to have these.

+1 to the initiative, I agree that there should be more standardized 
interfaces for both 2D and 3D! This probably calls for a REP "2D and 3D 
mapping interfaces", or similar?



>
> So here are my suggestions:
>
> - To add a GetPointMap message similar to GetMap but taking a 
> PointCloud2 instead of an OccupancyGrid. This could either be added to 
> nav_msgs or to something new like nav3d_msgs or map3d_msgs within 
> common_msgs.
This probably needs a clearer definition, what is a point map? Is it 
only aggregated end points after scan matching point clouds from a 
sensor? Another possibility would be the center points of voxels e.g. 
from octomap_server (in line to OccupancyGrid in 2D). Then the points 
alone are not sufficient since they are sparse and infinitely small. A 
resolution property like in the 2D case is needed for that.

ROI-like queries to the map server as a service call would be a welcome 
addition (e.g. give me all occupied cells in an axis-aligned bounding box).


Best,
Armin


-- 
Armin Hornung
Humanoid Robots Lab, Albert-Ludwigs-Universität Freiburg
Contact: http://www.informatik.uni-freiburg.de/~hornunga