Include huge always loaded distant meshes in the far field for Lumen Reflections

Hi there,

I think I know the answer to this question but was curious if there is someway of addressing this other than what we know.

We have a very large mesh (bounds of 30km x 30km by 10km) that is a tall tower-like object near the outer edge of our map. It’s used as a navigational point to be seen by players. It is placed ~30km away from the playable space.

It’s a low resolution mesh so we can force it into the far field without building a HLOD as it is always loaded but the issue is that unless we set our `r.LumenScene.FarField.MaxTraceDistance` to an equally far distance it doesn’t show up in the Lumen reflections.

I wouldn’t want to increase this number really high as having traces go such long distances seems risky from a performance point of view. In our specific case here it might be okay as it’s just a single tower that doesn’t have many objects between it and the camera so rays probably wouldn’t collide with many objects.

My question: is there a way to include a mesh in the far field scene permanently, irrespective of distance from the camera? Or does it just make sense to increase the `MaxTraceDistance` to include these meshes despite being a huge distance?

It would make sense for meshes that are out of bounds of the map (like mountains, landscapes and key landmark items) in a big open world map to be in Lumen reflections and not have to increase the `r.LumenScene.FarField.MaxTraceDistance` to be a huge distance to try and include these meshes in the reflections.

I looked at how the SkyLight is added and that uses a texture lookup and not a ray to a mesh which makes sense and doesn’t help us here.

Thanks in advance!

Hello,

Thank you for reaching out.

I’ve been assigned this issue, and we will be looking into how to get reflections for large, distant meshes for you.

Hello,

Can you please answer these questions to help us understand your use-case?

  • Are you using Realtime Capture on your Skylight, or a fixed cubemap?
  • Is the tower close enough to the playable area that the parallax effect is enough to be seen in reflections? IE, on one end of the map, does the tower look significantly different from the other end, due to seeing different sides of it?