Drawing trajectory of an object

[Daniel]

Could you please help me to attach the pencil tool to an osgb object?

[Samuli]

Have you tried to modify the pencil example code like this:

robot=viz.add('your_robot_name.osgb')
...
arrowLink = viz.link(mouseTracker,robot)

[Daniel]

I've tried it , but if you add mousetracker , I end up drawing with the mouse.

What I want is to attach the pencil to the end of the robot and the pencil draw the trajectory of the robot end effector