Godot: KinematicBody2d and RigidBody2d sometimes falling trhough one way platforms when another body stands on it

[doquen]

Tested on Godot 3.0.6 and 3.1-alpha and 3.1-master.
Ubuntu 18.10 operative system.

When using one way collision for platforms, if a body (kinematic or rigid) stands on another body, it sometimes causes it to fall through the platform.

Here is an example:

I've already asked in this issue, but apparently is different problem. I attached simple project to test, maybe my mistake.

Thanks
Gunzo.zip

[bojidar-bg]

Would be nice to have a confirmation from 3.1 master, as there were some changes to one-way collisions in 3226b44f793ec18f92341819e11ae20d68d0193e.

[doquen]

I'm sorry, i meant 3.1-master. I cloned the repo and compiled master branch and still get the same behavior. I previously had tried in alpha, that's why i said alpha. I'm editing the post.

[eon-s]

I was testing various things, looks like is related to CapsuleShape2D and CircleShape2D because I was unable to trigger it using 2 rectangle shapes.
Those shapes can make any of the bodies involved in the collision (from the top or the sides) to sink in the one side body.

[doquen]

You are right, using rectangle shapes on both body does not cause this effect... I'll try what happens with custom polygon shapes.

[doquen]

I have the same result with polygon shapes. The problem seems to be related with not normal collisions. i mean, when the collision happens with some angle.

[doquen]

Hi,
Testing more, i found that it can also happen with rectangular shapes, although is more difficult for this to happen. If someone gives me some guidelines, i could try to solve it myself.

[eon-s]

@PabloF7 if you want to give a try fixing this, contact devs on IRC, godotengine-devel on freenode (wait until next week until Juan is back), I guess that reduz and randomshaper are the best on 2D physics.

[doquen]

Ok, I'll contact them next week in the IRC channel. Thanks!

[doquen]

Just for the record, issue still exists in master.

[reduz]

This took a ton of work to fix...

[doquen]

Great Job! i'll try after work