Adding a post process volume to a blueprint

I have a post process volume in my scene (underwater effect) that works great in my third person game. I want to add it to a blueprint, however the only post process I can add to a blueprint does not have a bounding box. I need this bounding box as it detects when the camera (not player) enters the water. I tried creating a separate collision box and detecting on overlap begin/end to enable and disable the post process, however it would turn on post process when the player entered the water even if the camera was out of the water.

Do I need to detect when the camera enters the volume? What about multiplayer… I don’t want the global water post process turning on for other players!

Is there a way to do this elegantly?

If I could just add a post process volume straight into the blueprint that would be the best solution!

Hey Michael,

The most efficient way to do this would be to add the Post Process Volume with its bounding box at the waters surface. You will want test the height at which the post processing is applied to fine tune the transition, sort of like a buffer zone so it is a clean and accurate effect.

This will avoid any need to add it to a blueprint and will affect any and all characters who enter the volume. Below are some images of an example I created to help you visualize the set up.

Post Process Volume Placement

The thin blue line represents my water plane and the surrounding pink box is the bounding edges of my post process volume.

Underwater Look

Here is an image of the post processing after finding some decent values within various settings. If you have any other questions, let me know.

Regards,

Hi Andrew,

Thanks a lot for your detailed reply! I was aware that I could just place post process volumes into the scene, however my intention with adding them to a “water” blueprint would be so that it would be nested with all the elements of water, ie. a water surface plane, code for telling the player to swim, code for slowing down projectiles. Adding the post process volumes to the scene separately would mean having to place two elements into the scene wherever I wanted water.

Does this make sense?

Hey Michael,

Unless we are using different versions (I am using 4.8.2) Post Process Volumes Should be available as an addable component within blueprints already.

Post Process Volume as Component

As for placing the volumes, you are really placing one instead of two when turning it into a blueprint so if you are worried about saving time that shouldn’t be an issue. Especially if your bodies of water are all different sizes. Simply place the actual volume alone and copy the size of the volume into your Water Volume. Use wireframe when placing your actors as well.

Cheers,

Andrew, the post process component within blueprints is not a volume, it has no bounding box and can thus not be adjusted to your water.

To properly answer the question for anyone who wants to do this in the future, you will need a collision shape in your blueprint, most likely the same trigger that you use to set your water. If you add a post process component into your blueprint and then make your collision shape the parent of it, it will act as the volume for the PP.

6 Likes

Hey Traggey,

I have outlined your process below for those who need a visual of the process.

Post Process Volume Child Actor

Post Process Bounding Box

Inside the Post Process Box

Cheers,

2 Likes

I you want to add box dimension by construction script

1 Like

Hey bro, thanks alot for that, do you know if we can place an Physyc Volume too?

This works great, thanks!
I will add though, remember to turn off ‘Unbound’ on your post process effect for this to work only when camera is in the box collision.