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Pathfinder – Bi-directional Octree A* for Space Engineers

Use this script to get started: Control script: PathfinderNavigation

Alpha build – behaviour may change. While I haven't experienced any crashes, use at your own risk!

Note: Lag spikes during long distance path claculations is caused by path optimization. If you want no lag, set MaxPathOptimizationSteps to 0 in PathfinderSettings.xml (this will cause very zig-zaggy paths though).

• PathfinderDestination (Vector3D?) – set/clear target (null clears). Will automatically recompute path when set.
  
• PathfinderDestinationName (string) – GPS/beacon name to follow (matches grid name for beacons). An alternative way or setting destination, especially for mobile grids that don't have static position. Overrides PathfinderDestination property.
  
• PathfinderDestinationTolerance (double) – distance threshold for destination updates (default: 50m). When PathfinderDestinationName is set to mobile grid that moves, this determines the distance delta after which path is automatically recomputed.
  
• PathfinderMinDistanceFromDestination (double) – inner radius to skip when searching for destination (default: 0m).
  
• PathfinderMaxDistanceFromDestination (double) – outer radius to search for reachable destination (default: 50m).
  
• PathfinderMaxRdpDistanceFromDestination (double) – outer radius for collision avoidance destination search when dynamic path refinement is enabled (default: 50m).
  
• PathfinderEnableDynamicPathRefinement (bool) – legacy setting, replaced by PathfinderEnableCollisionAvoidance (default: true).
  
• PathfinderEnableCollisionAvoidance (bool) – if enabled, uses sphere-based path scanning to find paths around obstacles; if disabled, uses direct path to waypoints (default: false).
  
• PathfinderMaxCADistanceFromDestination (double) – outer radius for collision avoidance destination search (default: 50m).
  
• PathfinderCATarget (Vector3D?) – current collision avoidance target point (read-only).
  
• PathfinderPath / DPRPath (string) – serialized master path / collision avoidance refined path.
  
• PathfinderStatus – NotStarted / Calculating / Ready / NoPath.
  
• CurrentWaypointIndex – current master waypoint. When distance to current waypoint is less than IntentDistance, automatically checks if next waypoint is reachable and advances if path is clear.
  
• PathfinderMinAltitude / PathfinderMaxAltitude (double) – optional planet altitude clamps (sea level).

• RecomputePath – rebuild with existing destination.
  
• ClearPath – abort and reset.
  
• ResetSettings – reset OctreeAStar settings to default values.

• Control script: PathfinderNavigation
  
• Source code: GitHub – Pathfinder[github.com]
  
• Youtube: Pathfinder - playlist

• Sphere-based path scanning – samples a sphere around the start position using pitch (0-180°) and azimuth (0-360°) angles, prioritizing directions aligned with target + velocity. Path lengths scale with alignment (1 to CAAttractionFactor) and are divided by CAAttractionFactor.
  
• Sub-OBB collision checking – subdivides paths into agentSize-sized OBBs for granular collision detection, returning the center of colliding sub-OBBs as collision positions.
  
• Waypoint skipping – automatically advances to next waypoint if distance to current waypoint is less than IntentDistance and path to next waypoint is clear (single path check).
  
• Terrain collision handling – when terrain collision is detected during initial path check, sets collision avoidance target to collision point + CAMinAltitude, skipping alternative route searches.
  
• Intent obstacles – creates OBBs from current position to collision avoidance target (with agentSize/2 padding) to signal intended path to other entities.
  
• All collision types – uniformly checks voxels, static grids, velocity obstacles, and intent obstacles using the same sub-OBB mechanism.
  
• Distance budget management – uses scan budget (min of IntentDistance and distance to target) to limit search range. Budget decrements by path length when clear, or by (collision distance - OBB length) when blocked.

• CAAngleIncrement (double, default: 45.0) – angle increment in degrees for sphere-based sampling (pitch and azimuth).
  
• CAAttractionFactor (double, default: 10.0) – remaps dot product from [-1,1] to [1,CAAttractionFactor] for path length scaling.
  
• CAMinAltitude (double, default: 40.0) – minimum altitude above terrain for collision avoidance.
  
• IntentDistance (double, default: 100.0) – distance threshold for waypoint skipping and scan budget calculation.

• Additional Settings (debug + extra settings): %AppData%\SpaceEngineers\Storage\[3597348725.sbm_]Pathfinder\PathfinderSettings.xml.
  
• Diagnostics log: %AppData%\SpaceEngineers\Pathfinder_[DateTime].log.
  
• To hide path rendering: set RenderPath to false in PathfinderSettings.xml.
  
• To hide pathfinder messages: set ShowPathfinderMessages to false in PathfinderSettings.xml.
  
• Using collision avoidance is typically provides faster navigation because it will try to skip waypoints when the path to the next waypoint is clear. However it does get stuck sometimes :(