Matter-js: Prevent bouncing on collision with static bodies

[jack-guy]

I'm creating a tile-based game with Matter and I've noticed that no matter how I seem to configure my player's body, I can't stop it from bouncing when it collides with a static wall, even with restitution = 0.

Here's a reproduction (use arrow keys)

[Technostalgic]

Hey, it looks like the problem you are experiencing is because you are trying to move the player by directly changing it's position, as a result, the player's body teleports directly into a tile. This can cause unexpected behavior. Instead, you should be modifying the velocity of the player, instead of the position.

EDIT: like so: https://plnkr.co/edit/R3IDtpb0w7ZX74zhRomr?p=preview
Also, be sure to set the inertia to infinity to prevent unwarranted player rotations/movements, this way no physical objects can effect the player unless you tell it to.

[jack-guy]

@Technostalgic Thanks for the tip! Still believe this is incorrect behavior however. Maybe it'll be fixed by the CCD branch?

[liabru]

@Technostalgic is right, this is the approach you should take. The collision resolver can't do it's job unless you tell it what the body's velocity is, it's not a CCD related problem. If you still want to set position manually like that, you must also set velocity manually too for collisions to work correctly e.g.

  if (e.keyCode==38) {
    Matter.Body.translate(player, {x: 0, y: -3 });
    Matter.Body.setVelocity(player, {x: 0, y: -3 });
  }
  if (e.keyCode==37) {
    Matter.Body.translate(player, {x: -3, y: 0 });
    Matter.Body.setVelocity(player, {x: -3, y: 0 });
  }
  if (e.keyCode==39) {
    Matter.Body.translate(player, {x: 3, y: 0 });
    Matter.Body.setVelocity(player, {x: 3, y: 0 });
  }
  if (e.keyCode==40) {
    Matter.Body.translate(player, {x: 0, y: 3 });
    Matter.Body.setVelocity(player, {x: 0, y: 3 });
  }

Also take a look at the Body Manipulation example.