Visualisation of contact events in the engine. Wireframe objects are the actual physical objects. The small plain spheres are placed at the position of the contact (or the average of all points), and reacts to impulse. Impulse is one of the components of the forces applied on the objects while bullet resolves the world.


  • impulse > 1000: red material;
  • impulse > 1: yellow material;
  • by default: cyan material;
  • scale calculation: (3 + impulse * 0.00001) caps at 15.

To be precise, the impulse used here is the delta of the previous and current impulse.

The video shows only one of the 2 contact events you can retrieve from engine:

  • pairs: represents the relation between 2 objects in contact (visualised here);
  • per object: it is also possible to retrieve contacts for a specific object.

In future version, I plan to enable specific pair listening (“i want to know when this specific object touch this other specific object”).