Hello,

I'm currently transferring a large landscape from Houdini to Unreal Engine following a tutorial (link: https://www.sidefx.com/tutorials/procedural-desert/). However, after importing the landscape into Unreal, there are visible gaps between the tiles.

Details:

Total Landscape Size: 32,264
Tile Setup: I’m splitting the landscape into an 8x8 grid, which gives me individual tiles of 4,033x4,033 (as recommended in the Unreal Engine documentation).
In the Heightfield Tile Split node, my settings are as follows:

Tile Lower Overlap: 0
Tile Upper Overlap: 1
Despite these settings, there are still gaps between the tiles in Unreal Engine after the import.

Unreal 5.4.3
Houdini 20.5.332

Any advice on how to resolve this issue would be greatly appreciated!

Thanks in advance.

I don't remember all of the details on this tutorials setup, but I think it was based on UE4s World Composition, and there was even a labs tool that supported it. But now this type of workflow would be replaced with Unreal 5s World Partition system.

And what you can do it take your tiles and use a Heightfield Project and project it back onto a 32,264 heightield and import that as your landscape. And then follow the Houdini Engine docs World Partition setup to get this nicely partitioned in your level. https://www.sidefx.com/docs/houdini/unreal/worldpartition/worldpartition.html [www.sidefx.com]

The issue of visible gaps between landscape tiles in Unreal Engine is often caused by a mismatch in the tiling or blending settings during the import process. In your case, setting the Tile Lower Overlap to 0 and Tile Upper Overlap to 1 may be causing gaps between tiles. Try adjusting the overlap settings for both to ensure seamless tiling. Additionally, double-check that the tile size and export settings from Houdini match Unreal Engine’s recommended values for landscape tiles, particularly in how edges are blended.

I'm not sure if we're talking of the same issue, but Unreal landscapes can often show small gaps between subcomponents.
It seems to result from non-integer scaling factors, which are often the case when the landscape is output by the Houdini Engine plugin. Although it's not clear cut.

I have not been able to figure it all out, but integer scaling factors seem to be always good. Having one decimal digit is usually good, but not always. Two decimal digits are sometimes ok, sometimes not. Three decimal digits usually do not work, and more than that never work.

Scaling landscapes by half a percent can easily be too much, if you have neighboring landscapes. Hundredths of a percent should be ok, but you might need to search for a good magic value. The same magic values do not work for every landscape.
With some manual work you can probably find good values for yourself. In my use case I have a lot of landscapes coming out of a pipeline, so this manual value searching does not work.

This happens in both normal singular landscapes (between subcomponents) or in world partition (between landscape proxies)

I'm still investigating this, so don't take the above as gospel