Hi Indyzz, this is actually fairly straight forward once you get it set up.
First of all, I assume you are using the free World Machine, which means no bigger exports than 512, which translates in UE4 to 505x505.
So, in World Machine, open up the Project Settings. Looks like a ruler on the main toolbar.
Set the normal build resolution to 505x505. A terrain this size at 100% in UE4 is roughly half a kilometre square.
Then in the location area, set the width and height to 1km.
Then on the general tab, change your maximum elevation to something sensible. I personally use 3000m.
Then click ok on the project settings.
The way to do it is set up your terrain how you want it, with whatever nodes you are using. (perlin, erosion, terrace, whatever.) You can always come back to it later ofcourse to get it just right.
Then what I do to save myself some time, is create a checkpoint node at the end, this saves you from having to mess around reconnecting things when you make changes to your node layout.
After the checkpoint node, you want to connect a Height Output node. Double click on it to bring up the options, make sure it has a filename and is set to .png. I personally un-tick “use absolute path for setting filename” as I always save my World Machine projects in their own individual folder.
In order to create splatmaps you need to create more height Output nodes which are again connected to the checkpoint node, generally via a selection node as opposed to being directly connected. For example, a cliff splatmap would only want the cliff texture to appear on very steep slopes. In order to do this you should create a “Select Slope” node and then connect a height output to it. Then double clicking the select slope node will give you the options for inputting the slope you want to select.
Then for the cliffs height output, you need to set the format to Low Precision RAW.
For your height outputs, I recommend you set them to save every time you build the world. (The big green button builds the world, for better previewing)
Just to test its all working, I suggest you create at least two splatmaps, one for the cliffs, and one for everywhere else for example. Then you need to create a material in the UE4 editor. It only has to be very basic to test things.
Again in the editor, click on the landscape tool on the left hand side of the screen. T
ick the radial button to import from file.
Choose your base heightmap, not the splatmaps.
Then choose your material.
Then expand the layers section. Here you will see the layers in your landscape material.
Each used layer needs its own “Layer Info” which you can create or reuse here.
Once you have selected your layer info for each of the layers you wish to import splatmaps for, you should then click the dotted box and point the editor to your splatmap files.
Because we set the heightmap size to 505 and the map area to 1km, you should set the landscapes X and Y scale to 200, and tweak the Z scale to whatever you feel looks right. I generally find around 400-600 looks ok at this scale.
If that’s all set up correctly you should be good to hit import and see your landscape appear.
If the landscape materials don’t appear correctly at first, simply drag the material from the content browser directly onto your landscape. Or apply it again via the details pane.
I am in the process of writing a tutorial on the subject to put up on the wiki at some point in the future.
I hope this helps!