what if even a 16bit heightmap is too small for a very high landscape?

@Millionviews Actually, your original thoughts on how to tackle this(splitting terrain into several parts by height) were quite close.

The team I’ve used to work with had a task to create very steep volcano island. Its proportion had to be way beyond something earthly.

World dimensions were 4km x 4km and 10km in height. With conventional approach, flat beach areas did look okey, however as the landscape transitioned into volcano part, triangular, spiky artifacts plagued the place. Resolution increase was out of budget and aggressive filtering was just removing all important details.

The cure came in two parts. First was good use of tessellation, but it was not enough. The second move was to have each tile(512x512 tile size, 16 tiles per side) positioned at different Y.
While whole world height range was 10km, each individual tile was mapped to a range of 2.5km.
Outer square of tiles covered height range from 0 to 2.5km, then, moving inwards, next loop of tiles covered the height from 1.25km to 3.75km third loop 2.5km -5.0km fourth loop 3.75km - 6.25km and so on.
Central tiles had height range of 7.5km-10km. As you noticed, there was sufficient overlap between the tiles, chosen large enough to allow border between tiles to pass at varying heights.

This approach, coupled with ~0.48 vertex per meter resolution, resulted in pretty detailed terrain, even at high slope angles. Instead of having 65536 points for 10km, result was ~209k. I was not directly responsible for this implementation, so unfortunately, I cannot give you details, what software was used to export heightmap tiles and how accounting for tile specific Y position was done. I bet it is pretty straight-forward, but I don’t think such functionality is included by default in commonly used terrain generation packages. I guess that UE world composition does not allow you to offset levels in Z space either, without engine modifications that is. Besides, above-mentioned approach is not universal and cannot be easily applied for every terrain shape.

Looking at your pictures, I have a strong belief, that you are using heightmap renderer in a way it was never meant to be used. By that I mean trying to bring in very high frequency details in your terrain, instead of relying on other means for that. Brief glance at Gale crater geology leads me to conclusion, that you should be able to get away with what ue4 and world composition offers by default. Seeing your in-engine shots and cross-comparing it to what you would expect could help. Maybe there is something flawed on the way from WM to UE4 in your case.

Looking really good!!! I didn’t see you mention this but are you using displacement or WorldPositionOffset to create the more detailed terraces on the steep vertical sides, using a world aligned texture?


have you tryed a blur in WM? works fine for me!

Maybee you get away with 1.

Thnx Ryan! Appreciate! :slight_smile: I am using tessellation (displacement) with the world aligned texture node. (the complex one). I modified the node a bit to have the node merge two normals in one world aligned node.

Yes, the WM build is one of my major concerns. To make things worse, it all has to be done in one session. I managed to tweak the erosion settings to a minimum with reasonable quality. My computers are a bit more powerful than a default consumer pc. Hope the total time will around 2 a 3 days.

Yup, but the problem that would cover this trick is not the same problem as I am having. :wink:

Heey, thnx for the detailed feedback. Your workflow sounds indeed like I had in mind. The last days I tried a few things and I will settle with a much lower resolution of the total landscape. So instead of 250m, I tried 500m and the artifacts seems to be gone. Therefor, I don’t really need to split the terrain into several pieces. I would be a huge workload to get all the data merge together in Unreal anyway. I also decide to shrink the walk area more. For special landmarks and so I still can build a more higher resolution version. I tried to add highfrequenty detail because of the real organic look and feel of the landscape. It actually works. As an example: 1 meter stone is visible in World Machine and in Unreal I add tessellation to make this 1 meter stone a slate stone. (like in the images)
This way, the landscape looks organic, nature like, stony and desert wise also from far distance. So to sum up…I took a step back in terms of resolution and just see how that looks in Unreal. :slight_smile: