Crowds Control

Artificially intelligent, virtually real

Contributions to Recast/Detour

08 October 2013 // recastdetour // masa // navigation // reaching for Disqus...

In a previous post I’ve announced that, as a part of our work on MASA LIFE, the team will work with Recast/Detour and that we would release our updates to the community.

This have been effective since the beginning of the summer and we’re just releasing today a new version which is the first to be used in a released version of MASA LIFE, the upcoming (if all goes well, this week) v1.2. Our work is available on github at https://github.com/masagroup/recastdetour.

Introduced features

Modular crowd framework

DetourCrowd was a rather monolithical, we redesigned a large part of its basic framework with two goals in mind: modularity and usage safety. In the process we introduced several new concepts:

  • Navigation behaviors, self-contained navigation algorithms defining how agents take movement decisions, eg. how they update their velocity (cf. the user documentation), such behavior is assigned to each agent and used to update it, the existing path following and collision avoidance algorithms were encapsulated in navigation behaviors;

  • Indirect agents access, forbidding direct read or write to dtAgent, introducing explicit fetch/push queries based on the agent’s id, as a result it is easier to make checks (are we out of the navmesh?) and the users always safely manipulate data (cf. the user documentation);

  • Modular Update loop, allowing more complex update strategy by supporting the update of part of the crowd in different steps, environment, velocity and position (cf. the user documentation).

We introduced unit tests on ‘DetourCrowd’ in order to test the new features we introduced. We chose to use Catch mainly because it is dependency free and with an active community.

Additionally we created a simple framework to create functional visual tests for navigation based on JSON configuration files.

Known issues

This fork is still very young and several issues are remaining. The most important being:

  • Bad usage of the pathfinding queue in the path following behavior;
  • Dumb neighbors retrieving, we had to remove the previous proximity grid that couldn’t work properly with multi-level scenes;
  • Removal of the navigation test features from the RecastDemo application, we didn’t took the time to port them to the new framework.

Once we are fully happy with our state, we’ll send a pull request to Mikko and make these updates part of the “main” repository. In the meantime contributions and issue reporting are welcome!

We have nice features in the MASA LIFE pipe that will surely lead to new contributions. I’ll keep the community in touch on this blog or on the Recast Google Group.