# One-way PlatformEffector2D on moving objects
**URL:** https://discussions.unity.com/t/one-way-platformeffector2d-on-moving-objects/648007
**Category:** 2D
**Tags:** 2D
**Created:** [December 5, 2016, 3:44pm UTC](https://discussions.unity.com/t/one-way-platformeffector2d-on-moving-objects/648007 "2016-12-05T15:44:41Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@gmentat](https://discussions.unity.com/u/gmentat)
#### Post date: [December 5, 2016, 3:44pm UTC](https://discussions.unity.com/t/one-way-platformeffector2d-on-moving-objects/648007/1 "2016-12-05T15:44:41Z")
Can someone explain how to make a one-way PlatformEffector2D work on a moving 2D object?
If a platform is static (e.g. it doesn’t have a rigid body or has a completely frozen position) then it works as expected (objects beneath it can jump through it, others stay on top). But when I make the platform to be affected by the gravity and supported by two other blocks, the platform falls through the support blocks no matter which layer I set to the objects or to the effector’s Collider Mask.
---
### Author:  [@LiterallyJeff](https://discussions.unity.com/u/LiterallyJeff)
#### Post date: [December 5, 2016, 6:21pm UTC](https://discussions.unity.com/t/one-way-platformeffector2d-on-moving-objects/648007/2 "2016-12-05T18:21:57Z")
Edit:
PlatformEffector2D does not collide when impacted from the ‘bottom’, or opposite the configured angle. In that regard it’s like a Trigger and passes through objects.
You can add a secondary collider as a child object perhaps, which only collides with the support objects and not the player.
---
### Author:  [@gmentat](https://discussions.unity.com/u/gmentat)
#### Post date: [December 5, 2016, 8:46pm UTC](https://discussions.unity.com/t/one-way-platformeffector2d-on-moving-objects/648007/3 "2016-12-05T20:46:18Z")
I wish the docs had this info. 🙂
Adding a child object with a collider solved it for me. Thanks!
---
### Author:  [@LiterallyJeff](https://discussions.unity.com/u/LiterallyJeff)
#### Post date: [December 5, 2016, 8:55pm UTC](https://discussions.unity.com/t/one-way-platformeffector2d-on-moving-objects/648007/4 "2016-12-05T20:55:42Z")
> [@gmentat](#):
>
> I wish the docs had this info. 🙂
You’re welcome.
I edited my last post to more accurately reflect what is happening.