Issue with Moving Platforms and One Way Collisions

0 votes

I'm trying to make functional moving platforms with one way collisions enabled. Both the player and the platform are kinematic2d. Horizontal moving platforms? No problem. But if I try to move the platform vertically, two problems occur:

  1. Moving down, the player "floats" 1 pixel above the platform.
  2. Moving up, the player "sinks" 1 pixel below the platform, and falls through.

Has anyone encountered this before? Are there any tricks to avoid this behavior? I can avoid falling through by disabling one way collisions, but that still leaves the floating/sinking behavior and doesn't meet my design goals.

in Engine by (74 points)

This should be fixed in ver. 3.1 (with "Sync to Physics" option). Read more: https://godotengine.org/article/godot-31-will-get-many-improvements-kinematicbody

by (244 points)

Yeah, I know. But with no release date, I don't want to wait around for something that may or may not come soon. Looking for a work-around.

by (74 points)

Hi, as you know, it's a known bug... according to this link the fix will also be included in next 3.0 release (i suppose earlier than 3.1).

I've seen a work arround for angled one way surfaces in this video with ray cast. I think the same should work with platforms moving up. For platforms moving down, perhaps getfloorvelocity ( ) can help you update the velocity of your player (if it's a kinematicbody2d) so it does not float. If you can share the code, may be we can try some workarround.

by (3,445 points)

I tested a solution where A. I disabled onewaycollision when the platform was moving up and B. adjusted the offset of the sprite when it was floating. It looked "okay", was somewhat unreliable (only worked maybe 90% of the time). It could probably work great with a bit more refinement... But it seems like a lot of effort when the horizontal platforms work perfect with no code at all. I might just hold off until 3.1 unless I can figure out a more elegant solution.

by (74 points)

Hi, you coud also build godot from source yourself.. it's really easy and the solution is implemented there. I've tested it.

by (3,445 points)

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