Collision detection problems using libgdx

Newbie & Debugging Questions
#1

Hi.

I’ve successfully implemented the Box2D part of libgdx into my game, and it’s working fine. Except that my bullets on rare occasion pass through my enemies. I handle all the collisions manually by getting the contactlist from the world, and iterate through them. I’ve set the body-property “bullet” to true on my bullet-entities, but it doesn’t seem to make them update their collisions more vigorously and in smaller increments as intended.

What can I do? I would really like to avoid handling bullet-updates incrementally per update manually. Is there something I’ve missed?

#2

are they passing through the enemies because they are moving ‘too fast’ ? are they never actually colliding with the enemies? by making too big of movement steps per step?

sweep test?
add a collideable line between old position/new position of bullet?
make each world increment smaller steps, as to not ‘jump’ over a collideable enemy?

#3

Thanks for your reply, namrog84. Yeah, that’s exactly it, and that’s exactly the solution I’d love to get away from. I thought it might be handled in the framework already.

Is this really what we all have to do? The reason I implemented a physics engine, was so I could just fire-and-wait-for-contact. So I wouldn’t have to handle all the movement manually, but could use a simple linear velocity instead :frowning:
Oh well, I already have a Java2D implementation of this. I guess I’ll try to port that solution, if no one has any other suggestions.