Handle multiple collisions with KinematicBody2D

AntonAndrosov338

When three KinematicBody2D collide, then two objects collide, instead three

TwistedTwigleg

Welcome to the forums @AntonAndrosov338!

How are the KinematicBody2D nodes arranged and how are you detecting collisions? My hunch is that the issue is probably how the physics engine is solving is making it where one of the bodies doesn't see the other because it was solved before/after and so its positions (when solving) are slightly off.

AntonAndrosov338

@TwistedTwigleg said: Welcome to the forums @AntonAndrosov338!

How are the KinematicBody2D nodes arranged and how are you detecting collisions? My hunch is that the issue is probably how the physics engine is solving is making it where one of the bodies doesn't see the other because it was solved before/after and so its positions (when solving) are slightly off.

Hello! My nodes look like this:

I use move_and_slide, get_slide_collision and get_slide_count, in player`s script.

My code for handle collisions look like this:

TwistedTwigleg

Are you calling queue_free on the Fire KinematicBody2D node? Perhaps its being deleted before it can be registered in the physics world, which is why you are getting two collisions instead of three.

Though the GetSlideCollision function just returns the collisions a KinematicBody2D makes when calling MoveAndSlide, where each of the collision data returned is a different collision on a certain axis (I think). If two objects are on the same axis with each other and the same size, it could be the slide is a single long slide across two objects, instead of two distinct collisions with two objects. Not sure if that is the case though.

AntonAndrosov338

@TwistedTwigleg said: Are you calling queue_free on the Fire KinematicBody2D node? Perhaps its being deleted before it can be registered in the physics world, which is why you are getting two collisions instead of three.

Though the GetSlideCollision function just returns the collisions a KinematicBody2D makes when calling MoveAndSlide, where each of the collision data returned is a different collision on a certain axis (I think). If two objects are on the same axis with each other and the same size, it could be the slide is a single long slide across two objects, instead of two distinct collisions with two objects. Not sure if that is the case though.

Yes, you're right, but I want both of my fire blocks to activate when a player collides, not just one. How to do it?

TwistedTwigleg

What I might try is using Area2D nodes on the fire blocks to detect if the player is near/on them, and then the area_entered signal to detect if the KinematicBody2D has collided with it. You'll need to make the CollisionShape2D of the Area2D slightly larger than the CollisionShape2D it uses for collision so it sticks out just a bit, as otherwise it won't be hit by the player, but after that I think it should work.

If that does not work, then I'm not sure right off, but there is likely another solution. There may also be a way to use GetSlideCollision or the collision data from the KinematicBody2D as well, but I'm not sure what it would be right now.

AntonAndrosov338

@TwistedTwigleg said: What I might try is using Area2D nodes on the fire blocks to detect if the player is near/on them, and then the area_entered signal to detect if the KinematicBody2D has collided with it. You'll need to make the CollisionShape2D of the Area2D slightly larger than the CollisionShape2D it uses for collision so it sticks out just a bit, as otherwise it won't be hit by the player, but after that I think it should work.

If that does not work, then I'm not sure right off, but there is likely another solution. There may also be a way to use GetSlideCollision or the collision data from the KinematicBody2D as well, but I'm not sure what it would be right now.

Thank you very much!