So I’m brand new to world design in unreal. I have been researching using real world topography height maps but the area I want has no good data(it’s specifically bathymetric data in a not so wellapped region). Alternatively I have a hand drawn fantasy map I can use as reference. How would one go about using this reference to sculpt a map in the engine from scratch?
I’m not a world design artist but I want to help at least get your juices thinking. For your map, create a grid on it. If everything on the map isn’t drawn to scale (one kingdom is smaller than it should be compared to another) You should recreate the map with the proportions you want. Once the grid is in place, and everything looks proportional and ready to go:
measure how many squares wide and long the grid is. (we’ll pretend  x )
Make a flat plane and set the length and width to  x [scale number, say 1000] . If you want the Kingdom at A1 to be faaaar away from the kingdom at C10, consider that when picking the [scale number] .
Create a character and set its walk speed to something that looks pleasing. Also, make a mountain[Big box] in A1, and C10. Run from one to the other. If you feel you are covering ground appropriately to time spent running, your scale is good to go.
Cut the hard edges off your plane where you need, and anywhere there are mountains/forest/ocean at map end, dont worry about the plane. It’ll be covered.
(optional) Create the temporary grid lines on your plane, so you know whats going where and how much of it should be overlapping into the next zone.
Grab your sculpt tool and get to work on the clay-phase of your map. (actual mountains) block-in cities(they can be one large rectangle covering whole city for now)
From here, its just adding detail. You have two choices.
Go feature by feature (City complete, forest complete, lake complete, move on to next) completing your map.
Or, make everything slightly more polished but not time-consuming. block our your city(every building is a separate rectangle), basic trees stickers, etc. When you’ve got the look of your map down and your imagination is covering the ugliness(adding art/skin/texture, not shape, shape should be perfect) and it all looks chipper, and you’re happy with it, then start completing feature by feature.
Good Luck, and hopefully someone with more experience gives you some more detailed answers!
Thank you very much for the great answer and sorry for the super late reply. Will definetly use some of your advice going forward but for now have conceived a great way to create heightmaps from hand drawn maps. For those interested its as follows:
Take a photo or scan of your map and import it into an art app or program of your choosing. We use ibis ourselves which does just fine.
When in the new project map out on the map the area that is the highest point and create an easy to reference topographical map on top of your existing map in a new layer. Take every 500 ft for example and make it a new line following curvature of your land. (The smaller that number the more accurate the heightmap can be)
on a new layer: with this new map made create a grayscale gradient effect from top to bottom. Brightest white to darkest black respectively. When reaching each new line on the map layer you made use a nee shade of gray until you reach the black. Then simply smudge or gradient this entire map to make it as smooth or rough as you need. With enough practice this can be as good as real heightmaps. Also for better erosion effects and the like you can hand sculpt after import into unreal or use other programs like Gaea which uses a great blueprint style of map altering that can achieve amazingly realistic effects.
Adjust Z scale in Unreal according to total height from lowest to highest point. If the current Z scale is 100 (default), and the total height is ~65,000 (650 meters), then increase the scale to increase the total height of the terrain. Moving the terrain on Z allows for adjusting how deep a lake or other feature can be, and how high a mountain or other feature can be. For actual world maps in simple height form, there’s a free height map generator at:
Remember to import it to a program such as Photoshop, an image editor, to prepare it for import into Unreal. Blurring, contrast, and other effects are applicable to making the initial render of the landscape in Unreal workable.
Abdsolutely z scale adjustment is nedded when doing this from a fantasy or fake terrain. Importing real world heightmaps is much much easier with the method you mentioned as well presto423.