Hello everyone,
I have put together a tutorial for L3DT terrain exporting and importing into UE4.
links:
Below is the text in the video and some things left out and some things missing. 
First off I a deaf so there will be no voice. I don’t have a microphone and have no idea how loud I talk anyway.
I have dreamed of making a virtual world for many years (Kingdoms of Whren which I now just call Kingdoms) and have tested many engines to work with my design going back as far as 1994.
There are several engines available now that can do massive worlds but they lack key features needed or will take enormous efforts to make it function as a massive world Let alone a MOVW (Massively Online Virtual World).
I was working with Bigworlds engine up until February when I installed Windows 8.1 64 bit and forgot to save my BW license key so I lost access to the tools and Bigworlds has ignored my emails.
I had many months of work go down the tubes.
It was a personal project anyway since no one was interested and could never get the highly skilled team I needed. I almost had investors but that went away due to no interest by the public.
I decided it was not going to be commercial or public so I had assets from and Oblivion all ported out to BWT and was working on code.
I started coding in 1981 mostly assembly and C++ but Python only a couple years so it was a bit difficult to get up to speed.
Being depressed and feeling defeated I just gave up. I did a mod for but I can’t stop thinking about my project.
I was checking engines a few weeks ago and seen UE4 is now free so I though I would go ahead and check it out and begin working on the project again for something to do. Since it comes with source I can add the clustering and the MySQL needed if I ever get that far.
HOWEVER!
I noticed many people have issues with terrain or they just don’t know how to do it and there is little information available. I decided to make a video for you and maybe help the community out and some budding developers may be inspired to make such a commercial project.
ANYWAY enough of about me and my projects.
I am going to explain how to import INSANELY large maps into Unreal Engine 4.7.6 using L3DT Professional.
AAron of L3DT has made a few things easy with additional scripts which you will see later. You need L3DT 14.1X or newer for the over lapping tiles feature. If you don’t have it, it makes it more difficult but still doable. Ask me I will explain it in detail.
I am using L3DT 15.1 development build which has this feature. This will probably work with World machine also but may need some adjustments.
So the tools we need here are L3DT 14.1X or above and UE 4.7.6.
Let’s get started.
I make most of my maps at 1 meter resolution however here we are going to do a design map for the end product instead of just using blank design map and painting it out or just some random map that we generate. We also want a high detail terrain so it will call for a few passes to make it look good.
Start out will a 4096 design map.
Set the edge wrap so we can copy and paste the design to adjust landmass if needed.
We want 16 meters per division at his point with 32 HF/DM ratio.
Our end product will be 16K pixels square at 2 meter design or 32 Kilometers.
The world scale of around 64 kilometers.
It is insanely large world in the end as you will see.
And if it isn’t big enough I will show you how to tile the mosaics to even larger maps!
I set the average altitude to about 60% land and 40% water.
You can set it to anything you want but I am after a continental landmass.
I set the altitude range low and the scale of features really low because we don’t want to have miles of nothing between points.
I set noise level low also. It is entirely up to the designer here this is just my preference.
We may need to run several attempts here.
Once we have a somewhat decent looking DM.
We can check the design so let’s check a few areas of this design map.
Select an area and generate the selected area.
Maybe add some cliffs or more erosion.
Move around the map and make some adjustments.
Maybe a plateau or a mountain would help?
If it looks good I try to align the mass of the land into the center.
I then select the landmass and copy it to a new layer so I change the design map HF/DM ratio to 16 and copy and paste the design from the new layer back.
Usually it is not exactly the right size for the map so I have to adjust the DM and resize it.
Ok. Save it.
Now we have a basic map we generate the entire terrain.
The nice thing about L3DT is you can adjust things on the fly so it does not matter what you use here for tiles needed later.
We can also make up to 16 giga-pixel maps which I have done and infinite sizes with design inflations.
The only limitation of world size is your hard drive.
This will take awhile so we will come back later.
----------------after map generated.--------------------
Once this is finished we save all our work again.
Review the height field and adjust the altitude and horizontal scale if needed then save it and close it.
Now re-import this map as a design map.
Set it to 8 pixel down sampling and 16 pixel up sampling so it gives a 16Kx16K pixel terrain or 1 giga-pixel HF.
Set the mosaic to 1024.
This will make a 16 Kilometer terrain with 16 tiles in X and 16 tiles in Y axis.
Ignore the map size because it has to be adjusted after the design map is imported.
Here we set the noise low and erosion to what we want.
I go hog wild here on erosion.
Go back to the area we made the cliffs and redo it since it gets clobbered when we import the design.
Resize the design map and set the resolution to 1 or 2 meters per division.
Now generate the terrain.
This can take up to a day or more to generate depending on how much terrain erosion and how big you make the map.
Now this is IMPORTANT!
Once it is generated save this new map and then also save as a different map.
Open the new save and flip the Y axis.
The reason is the terrain weights will be inverted since the map output is inverted for a Raw and not for the weights.
If you use invert flag on export the terrain tiles will be all be flipped and will never align!
Export this new inverted map as overlapping tiles.
Since we used 1024 for the original tiles set the tile size to 1017 as per UE required configuration.
Make sure to check unreal format so you get the leading underscore in front of the y.
Now export it.
L3DT will resize the terrain and split it to this specification.
For this demonstration I am doing just terrain.
Making weigh maps is another topic but knowing what is here should help you since this process is all similar.
Exit L3DT.
Now open UE4 and make a project.
Delete the tile and player start and save it as blank or something you can remember it is just the persistent level.
See documentation on Activating World Composition.
Activate World Composition.
Open the levels and import the tiles.
Now this terrain is 16 by 16 so adjust x and y by -8 so the terrain aligns with the center of the world.
Leave scale at 100 for now and see how it looks on import.
You can redo it later and adjust the scales if needed.
Now import it.
Check it out.
Still not big enough?
Go back to L3DT and export it again under a different name.
Do it as many mosaics as you want.
On import set x and y accordingly.
Example - To mosaic a mosaic just set the tile offset to -24, -8 for the left side and 8,-8 for the right side.
Now the terrain will need to have a small seam fix but it is now 48 Kilometer by 16 kilometers and repeating.
Make new terrains and add them as long as the name of the mosaic is different it will import as a new terrain.
Now you can tweak the terrain and do all the things you want but the major parts are completed for you.
Well that is all for the terrain.
Hope this was helpful to someone.
Please, sounds interesting