How to have collision on platforms work from the top but not the bottom?

In a lot of platformer games I’ve noticed there are certain times that you’re able to jump through platforms from the bottom and clip through but be able to walk on top of - anyone have any ideas on how this could be achieved in blueprint?

I think you can edit the collision manually by clicking on the mesh and playing around with the properties. I had an issue where i had buildings but the collisions was stopping anyone going through door openings so i had to edit the colisions.

An alternative quick workaround is disable the.collisions as you jump allowing you to pass through then re enable them again before
you land.

Two old-school approaches: A. Place a trigger below the platform. If the player enters then momentarily disable the collision on the platform above. If needed, you can add a condition to check if the player has just passed through a trigger above the platform. If so, do nothing. 2. Have two collision stages. The first larger collision box, trigger or mesh, has passive collision (equivalent of UDK Touch event). Once that’s triggered do a velocity / directional check on the player that triggered it. From that choose whether to quickly enable or disable collision on a second inside blocking volume / mesh etc…

that would depends on your needs actually. you can have the trigger solution that franktech proposed, or have the platform controling its own colision depending on the player’s height, or have the player disable its colision whenever it upward velocity is bigger than zero (wich only happen when jumping). But one thing is sure, you will need your platform to be a blueprint and not a simple static mesh.

I personaly chose to make my platform a blueprint, wich would check the player’s height and velocity. When the player’s height is bigger or equal to the platform height and its velocity is either negative or equal to zero, then activate the colision of the platform, otherwise the collisions are disabled on this platform. and every platform is doing this check.

Thank you all for your input
@Enigmaa - Since I have a double jump its sort of hard to tell when exactly the character will be colliding through the object - so it might be that I have to figure out a different method than simply turn off collision when jumping.
@FrankTech I’ll give that a try Thanks so much :slight_smile:
@JX53mb thank you for the input -