does rtabmap core project need the g2o to compile

[mantouRobot]

Hi~
      I found that the rtabmap core can compile successed without the g2o install. Does rtabmap core project need the g2o to compile? if not, how can the rtabmap use the g2o?
      Thank u~

[matlabbe]

Hi,

g2o is optional indeed. The core project can work without g2o. TORO graph optimization (which is built inside rtabmap) is used if rtabmap is not built with g2o or GTSAM support. These are three different approaches for graph optimization.

cheers,
Mathieu

[mantouRobot]

Thank u for reply~
      So I no need to choose the optimizer strategy because in the compile the rtabmap can choose for me. By the way, for the indoor environment, which strategy is best?

[matlabbe]

Hi,

The parameter is named "Optimizer/Strategy" (default "2" if built with GTSAM, "1" if built with g2o, "0" otherwise).

For room size environments, g2o or GTSAM would give similar results and better quality than TORO. However, TORO seems the most stable (give always a solution) for very complex multi-session graphs, though sometime gives strange errors on some links. Multi-session maps are better optimized with GTSAM than with g2o, though both can fail to find a solution sometime (which makes the map break).