Custom BT Condition Nodes in C++

Source: ros2-copilot-skills custom BT condition C++ skill

Why This Matters

Custom condition nodes are how a project expresses its own notion of readiness, safety, mission state, or environment-specific triggers. These checks often matter more than action implementation because they shape the flow of autonomy itself.

Distilled Takeaways

• A condition node should answer one clear question about robot state.
• Custom conditions are valuable when the project has state semantics beyond Nav2's built-ins.
• Condition nodes should remain cheap, predictable, and easy to reason about.
• If a condition is unstable, the tree will feel unstable too.

Practical Guidance

• Keep conditions focused and side-effect free.
• Use clear naming so the tree reads like a meaningful decision flow.
• Watch for flickering conditions under noisy inputs and add hysteresis or filtering where needed.
• Avoid mixing long computations or action behavior into a condition node.

Corroborating References

• BehaviorTree.CPP docs
• Nav2 behavior tree docs

When to Read the Original Source

Go to the original skill when you want the custom-condition node implementation pattern and reminders about how condition semantics affect tree stability.