Map misalignment after reprojecting from 27700 to 3978 in FME

Cesium for Unreal
1

Hello all

I have successfully reprojected and shifted the map that I would like to use in Unreal into 3978 via FME however I have run into a hurdle.

The reprojected map has an incorrect rotation, by quite a lot! And does not perfectly align with the Cesium data, I feel like I am missing an obvious step here.

2

Hi @dardonal,

Sorry, it’s hard to tell what’s going on here. It would help us if you could share more info about yoru situation, such as:

  • What versions of Unreal Engine and Cesium for Unreal are you using?
  • How did you reproject and shift your map?
  • Are you able to share screenshots of your data? If so, could you share one that shows off the misalignment?

Thank you in advance!

image

3

Hi Janine,

Thanks for replying, i really appreciate it.

The version I am using is 5.3, but I’m unaware of that being the issue.

As far as I’m aware the problem is that the reprojection and the shifting of the map via the georeference has worked correctly but the problem is I feel there is a missing step to rotate the map by an exact vaule so that the map is a use able orientation.

In the two images I have attached you can see the workflow that I’ve used in FME and the other picture you can see the original map in red and then the reprojected and shifted result in white.

tmp_4c4d0a90-1761-4164-906a-a1b220a59d86
tmp_4c4d0a90-1761-4164-906a-a1b220a59d861584×920 213 KB

tmp_ec2e28be-d40a-41c2-b25b-86d71d88a1c2
tmp_ec2e28be-d40a-41c2-b25b-86d71d88a1c22143×947 134 KB

4

Hi @dardonal,
It’s hard to say what’s going on there, especially since we’re not experienced with FME ourselves. It might help to see the screenshot of your data in Unreal on top of a basemap, so that we can see how they align. We’d also like to hear all the details about how you get this data into Unreal. I see “DataSmith” in your FME graph, so are you imported it via UE’s DataSmith plugin? If so, you may need to reach out to Safe Software or Epic for help, as it doesn’t appear that Cesium is really involved at all in that case. However, if you’re importing it via Cesium ion and 3D Tiles, please walk us through how you’re doing that.