# Ocean 4.26 underwater post process issues **URL:** \ **Category:** World Creation\ **Tags:** Water, ocean, unreal-engine, UE4-26, question\ **Created:** [December 6, 2020, 7:38pm UTC](https://forums.unrealengine.com/t/ocean-4-26-underwater-post-process-issues/475509 "2020-12-06T19:38:47Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![Comatos](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Comatos](https://forums.unrealengine.com/u/Comatos)\ **Post date:** [December 6, 2020, 7:38pm UTC](https://forums.unrealengine.com/t/ocean-4-26-underwater-post-process-issues/475509/1 "2020-12-06T19:38:47Z")
I cant figure out how to extend the post process, its not working as unbound for underwater, and I cant find access to it. The underwater section of my map ends at the end point of what looks like the post process box attaches to the spline. ---
**Author:** ![ixm.ibrahim](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@ixm.ibrahim](https://forums.unrealengine.com/u/ixm.ibrahim)\ **Post date:** [January 6, 2021, 1:34am UTC](https://forums.unrealengine.com/t/ocean-4-26-underwater-post-process-issues/475509/2 "2021-01-06T01:34:30Z")
Hello! I just had this question myself and went through a lot of experimention to figure it out… you need to adjust the “Collision Extents” for the WaterBodyOcean actor. From what I understand, the post processing only works within the collision bounds, so if you change one, the other will be affected. ---
**Author:** ![Comatos](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Comatos](https://forums.unrealengine.com/u/Comatos)\ **Post date:** [January 6, 2021, 11:36pm UTC](https://forums.unrealengine.com/t/ocean-4-26-underwater-post-process-issues/475509/3 "2021-01-06T23:36:58Z")
Awesome thanks for the info! ---
**Author:** ![3S\_Interactive](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/3s_interactive/32/499107_2.png) [@3S\_Interactive](https://forums.unrealengine.com/u/3S_Interactive)\ **Post date:** [January 16, 2021, 7:41pm UTC](https://forums.unrealengine.com/t/ocean-4-26-underwater-post-process-issues/475509/4 "2021-01-16T19:41:52Z")
Do you know if there is a similar tweak for the WaterBodyLake/WaterMeshActor? If I increase the Channel\_Depth to 2000 (in the default 4.26 WaterTestMap → WaterBodyLake example) then it causes a similar offset issue where the underwater post process doesn’t engage until you are near the centre of the lake. Unfortunately, there is no ‘Collision Extents’ equivalent to tweak. There’s presumably an ‘extent/bounds’ setting somewhere, but I can’t find it. ---
**Author:** ![ixm.ibrahim](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@ixm.ibrahim](https://forums.unrealengine.com/u/ixm.ibrahim)\ **Post date:** [January 17, 2021, 3:53am UTC](https://forums.unrealengine.com/t/ocean-4-26-underwater-post-process-issues/475509/5 "2021-01-17T03:53:26Z")
I was able to replicate your bug by creating a new landscape and _just_ adding a lake: when I move the camera to the lake floor or just under the waves, I didn’t see any underwater post processing effects in those areas. There is a “Enabled” checkbox for the lake’s “Underwater Post Process Settings” , but it’s already checked… and unchecking it just removed the effect entirely. The only fix I found was adding an ocean to the landscape and set the splines so that it’s outside the landscape (so it doesn’t deform any part of the terrain) - this automatically fixed the bug without having to change any collision extents. However, this fix is limited to lake depths above [about] 30,000 (should be fine for most lakes!), as it doesn’t seem to render the underwater effect below that. Even if I changed the Z Collision Extent for the ocean to 100,000, nothing changed… in fact, no matter what I changed the Z Collision Extent to, it didn’t seem to make any difference. Only changing the X and Y made a difference (or at least a difference I could see, as the post processing box for the ocean changed when I changed the X and Y, but not when I changed Z). From what I see, changing the Z collision extents is probably a bug in the plugin itself. **Tl;dr** : add an ocean around your entire landscape (unless you already have one), and that should fix the error as long as your lake isn’t just a really thin, deep ocean. ---
**Author:** ![3S\_Interactive](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/3s_interactive/32/499107_2.png) [@3S\_Interactive](https://forums.unrealengine.com/u/3S_Interactive)\ **Post date:** [January 17, 2021, 3:34pm UTC](https://forums.unrealengine.com/t/ocean-4-26-underwater-post-process-issues/475509/6 "2021-01-17T15:34:34Z")
Thanks for the tip ixm.ibrahim (and the mini investigation), it works. I didn’t really want to add a whole body of (hidden) ocean in my scene just to make the lake underwater transition work, but I’ll happily use this trick for now, until there is a more permanent fix. Well done for finding the hack. ---
**Author:** ![object22](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/object22/32/721155_2.png) [@object22](https://forums.unrealengine.com/u/object22)\ **Post date:** [February 2, 2021, 10:03pm UTC](https://forums.unrealengine.com/t/ocean-4-26-underwater-post-process-issues/475509/7 "2021-02-02T22:03:48Z")
Having the depth issue with the ocean body, the terrain max depth from 0 is about z: -25500 but the ocean post process effect (lower bounds) stops at z: -20000 leaving a gap. I cant figure out anyway to extend it in negative z aside from creating additional post process volumes. ---
**Author:** ![SpudCrowley](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@SpudCrowley](https://forums.unrealengine.com/u/SpudCrowley)\ **Post date:** [March 16, 2021, 2:54am UTC](https://forums.unrealengine.com/t/ocean-4-26-underwater-post-process-issues/475509/8 "2021-03-16T02:54:23Z")
I had this same issue with the lake and I found that adding more spline points fixed things. ---
**Author:** ![Zercury7](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Zercury7](https://forums.unrealengine.com/u/Zercury7)\ **Post date:** [March 4, 2023, 3:57pm UTC](https://forums.unrealengine.com/t/ocean-4-26-underwater-post-process-issues/475509/9 "2023-03-04T15:57:46Z")
Old post, but I followed this video and was successfully able to fix the post process depth issue without adding an ocean body to the scene. Specifically around the 5:30 mark. [Let's Build the RPG! - 16 - Unreal Engine 5 Water System Beginner Tutorial - Lakes and Rivers - YouTube](https://www.youtube.com/watch?v=lMgCxZqvZ80) Changing the Channel Depth seems to increase the post process depth. Side note: Your landscape seems to need “Enable Edit Layers” checked for this value to dynamically edit the landscape geometry. ---
**Author:** ![twobalo](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@twobalo](https://forums.unrealengine.com/u/twobalo)\ **Post date:** [March 27, 2023, 3:49am UTC](https://forums.unrealengine.com/t/ocean-4-26-underwater-post-process-issues/475509/10 "2023-03-27T03:49:51Z")
Same issue with River body. Trying lake first then River worked too. ---
**Author:** ![FXHochban](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/fxhochban/32/482168_2.png) [@FXHochban](https://forums.unrealengine.com/u/FXHochban)\ **Post date:** [January 16, 2024, 4:08pm UTC](https://forums.unrealengine.com/t/ocean-4-26-underwater-post-process-issues/475509/11 "2024-01-16T16:08:31Z")
Thank you for your post it solved my problem. Using UE 5.3.2 One thing to note for others that may find their way here: I did not have “Affects Landscape” enabled and as such was unable to change the Channel Depth. So need to enable “Affect Landscape” first, then change the Channel Depth and then disable Affect Landscape. All good. Cheers ---
**Author:** ![axel08itachi1](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@axel08itachi1](https://forums.unrealengine.com/u/axel08itachi1)\ **Post date:** [January 28, 2024, 1:01am UTC](https://forums.unrealengine.com/t/ocean-4-26-underwater-post-process-issues/475509/12 "2024-01-28T01:01:43Z")
As unintuitive as that was, it worked. It does make sense to some degree as the “Affects landscape” option makes the value of Channel depth go deeper while also extending the post process volume. Thanks, this should be marked as the solution! ---
**Author:** ![RS\_3MMFIRE](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@RS\_3MMFIRE](https://forums.unrealengine.com/u/RS_3MMFIRE)\ **Post date:** [March 31, 2025, 12:52pm UTC](https://forums.unrealengine.com/t/ocean-4-26-underwater-post-process-issues/475509/13 "2025-03-31T12:52:24Z")
If anyone is still struggling with having a deeper post process volume range for a lake / river, just temporary turn on “affect landscape”, go to the Curve settings under Terrain and increase Channel Depth as much as you want your ppUnderwater to be affected, and then turn back off “affect landscape”