Null pointer error in thread

[GoToLoop]

Implement a method named post() draw() inside your class A, and then registerMethod() it:

Fisica's FGearJoint

I’ve taken a quick look at Fisica’s source code and found out the reason for the NPE is that invoking method getBox2dJoint() on both FRevoluteJoint objects return null: println(revJointA.getBox2dJoint()); // null println(revJointB.getBox2dJoint()); // null But mysteriously after the 1st draw() iteration, those same statements don’t log null anymore. So I’ve used registerMethod() in order to setup a post() callback which would be run once only and then got unregisterMethod(): Processing.GitHu…