Water, LOD and You

[Braggi]

I've run into something new here in messing around with landscape LOD generation. I have perfect the methods for generating visible distant land and textures through a combination of using the CS and TES4QLOD. (So far, so good.)

Now, where I am running into the problem is under water. The generated distant land always appears after a certain depth on the sea bed, creating a flat piece of terrain and blocking out any view of the deeper ocean floor. Everything above it in the water shows up fine - all land contours are correct as expected. Further, when in the water, you can see the LOD from above, but not from below.

At first, I thought is was merely a matter of regenerating the distant land and textures, but after multiple tries of cleaning out the LOD meshes and textures folder then generating from scratch, the problem persists.

I have a two thoughts on this and wanted to know if anyone else has encountered and/or conquered this problem.

1. Would getting the CS to re-calculate land normals and then generating LOD affect this somehow?

2. Is there a depth limit that the seabed must not exceed in a height map that Oblivion insists on enforcing (I.E.: it's hard coded in.)

If it is a hard coded limit, I'm pretty certain I am still well within it - there are areas off the coasts in the vanilla game that drop drastically deeper then any of my ocean depths go and no LOD issues show up in them. (Examples: The coastal area around the final dungeon where you confront Umaril in Knights of the Nine is much deeper in spots then any of my terrain, so far as I can tell. Also some of the coastal waters near where the Vile Lair plugin takes place are deeper too.)

Additionally, this problem is occurring in a separate land mass and world space, located in its own load-order independent ESM that has been cleaned and re-cleaned (both from the start, when I converted the land ESP to ESM, and each time before any later merging of landscape changes to the ESM) by TESGecko.

Any thoughts on this one?

[sandor]

Could you post a link for a screenshot showing this problem?

TIA.

[Braggi]

Certainly - and thank you for the reply Sandor.

Here you are:

1. and 2.: These images show the problem better then I can describe it. It seems pretty clear to me by the texture difference alone that the distant land models are being rendered with a specific depth limit to them.






3. The third image shows the same spot viewed from below - no problems with false flat spots appearing, since the texture is only on the upper side. It also helps to give some idea of the depth I mentioned - my test character was literally touching bottom when this shot was taken. The curved edge above is where the water and shoreline meet - not terribly deep by any means.


(The clearness of the water is due to a mod I enabled for troubleshooting underwater areas. the problem appears whether that mod is enabled or not.)



I hope that helps clarify. I am really puzzled as to why this problem keeps persisting, even after generating LOD land and textures from scratch.

?(

Some further information to help as well - the flat bottom limit exactly matches what I had when I first imported the height map using TESAnnwyn. However, I later adjusted all of the undersea areas to add variation in the sea bed using the height map editor in the CS. For some reason, the old data seems to be overriding the new.

This is from my personal High Rock ESM - I use it as a test bed before applying new techniques to the Balfiera project I'm working on with Jmanowar. Balfiera is currently still at the stage where the sea bottom is all flat, for the moment. I want to sort this problem out first, before touching that particular land mass.

[sandor]

The LOD mesh is visible, please check this post.

[Braggi]

Actually, I have generated fresh meshes through the CS at least three times - that is the puzzling part for me. I have generated new LOD without making any landscape changes and I still get this effect.

Here is my exact method, used each time - feel free to tell me where I am falling down.

1. Got to Meshes > Landscape > LOD and delete all meshes within this folder.
2. Go to Textures > LandscapeLOD > Generated and delete all texture DDS files in this folder.
3. Open the ESM in the CS, go to Height Map Editing.
4. Refresh overview, select a quad and click "Generate LOD" then "Full"
5. Let the CS create the LOD meshes then repeat ofr each quad of the height map.
6. Close the CS once finished.
7. Run TES4QLOD to create the textures for the LOD.
8. Test in-game.

I must add that I have done a fair bit of landscaping above the water line since I re-sculpted the sea bed and the LOD above the water always generates properly from scratch and works as expected. I get this only under water and after creating fresh LOD.

Does that help clarify a little?

[sandor]

The procedure is okay, however the screenshots clearly show the LOD mesh.

Meaning the actual land is below the mesh.
If you walk into the sea towards the "film" you can walk through it and see the bottom of the sea beneath it.

Did you try that?


Could you send me the esm (and the LOD meshes/textures) plus the coordinates where the problem shows up?

[Braggi]

Originally posted by sandor
The procedure is okay, however the screenshots clearly show the LOD mesh.

Meaning the actual land is below the mesh.
If you walk into the sea towards the "film" you can walk through it and see the bottom of the sea beneath it.

Did you try that?

Yes, that is it exactly - I walk (or in this case swim) through the mesh. Screen shot number 2 was taken just before that happened and screen shot number 3 was taken just after.

Originally posted by sandor
Could you send me the esm (and the LOD meshes/textures) plus the coordinates where the problem shows up?

As far as where it happens, it affects the entire sea bed - which covers quite a bit of ground in the mod as a whole. (High Rock and Balfiera both have a lot of water.) So, if I send you the ESM you won't have to look hard to find it.



And that brings me to my last question. I'd be happy to send you the ESM, however it is 34 megs in size - so how would you suggest I get it to you?

[sandor]

Originally posted by Braggi
Yes, that is it exactly - I walk (or in this case swim) through the mesh. Screen shot number 2 was taken just before that happened and screen shot number 3 was taken just after.

--> It's the LOD mesh

Originally posted by Braggi
And that brings me to my last question. I'd be happy to send you the ESM, however it is 34 megs in size - so how would you suggest I get it to you?

Upload it to fileupload.
You don't have to register, make sure you copy the admin link as well otherwise you can't delete the file afterwards.

[Braggi]

OK, I have uploaded the ESM, LOD meshes and LOD textures for you - 44+ MB in size. Check your PM's for the link itself.

As far as a good place to check, here are some co-ordinates I use for testing:

Betony Isle Coast: 10,18 (this is in the area where the screen shots were taken)

North Point Coast 01: 65,99

North Point Coast 02: 63,106

Western Eltheric Ocean Depths: 25, 107

Central Illiac Bay: 45,47

You can also use the prototype regions from the Region Editor to get around to other locations if you like.

Note also that I hate messing with negative number co-ordinates, so the quads for the height map start at 0,0 and stay within the positive quadrant in the CS. (I designed the land mass ESM that way for my own ease of use, since this is a personal project that I am modding alone for fun and education.)

I ask is that you not release this to anyone else - I don't want to create any competition for TYOB and Deeza in their High Rock mod. (They are both working hard and I want to encourage and support them. Though I am committed elsewhere, I hope they complete their version and release it.)

Let me know what you come up with and how things work... and have fun poking around in High Rock.

[sandor]

Originally posted by Braggi

I ask is that you not release this to anyone else....

Don't worry.
ST never releases mods or assets from mods without permission because we don't want people to release our models etc. without our consent either.