Lose shadow detail at a distance

Hi All, First up - sorry for any silly mistakes or questions as Im verrrrry new to the UE4 engine

I have an architectural walk-through project in which I am losing important shadow detail as well as ‘crispness’ in the model display at a distance like in the windows glazing bars blending in the joins. I assumed this is related to maintain reasonable performance in the model however we aren’t even close to struggling with this PC yet so if I can do something at the expense of performance I don’t mind.

We aren’t using lightmaps (forced no precompute) because if we have to wrap all the meshes the workflow from ArchiCAD to UE4 grows to exponentially to the point where feasibility is out the window well and truly once we process all the bits and pieces.

So far I have tried the following from reading the forum

  • Quality is set to epic across the board
  • ‘Generate Mesh Distance Fields’ is on (this improved the problem somewhat but not quite enough)
  • Mesh is set to movable

It does seem that the mesh is almost ‘smooth’ and losing resolution, so I was thinking maybe there is a LOD setting I can tweak to maintain full detail in the mesh and shadows at a distance?
If someone can point me in the right direction or even to another post (I think I’ve read hundreds by now :P) so I can crank up the detail that would be greatly appreciated!

Let me now if you need any further details in order to help, Thank you!

Hi Kyle,

When using Movable lighting from a Directional light the Cascaded Shadow Maps will reduce quality at further distances to help with performance. You can adjust some of the settings in the Directional Light’s Detail’s panel under Cascaded Shadow Maps to help improve this.

The Wiki guide here can help go over some of the settings: A new, community-hosted Unreal Engine Wiki - Announcements - Epic Developer Community Forums

Additionally, you may find that you want more cascades to spread the shadow maps over so you can use the console command r.Shadow.CSM.MaxCascades 10 to increase this to the max count. Then you can set the number of cascades in the directional light to 10. At this point use the Distance and the Distribution Exponent to adjust how the quality is spread across the cascades.

Mesh Distance Fields. If you’re enabled these make sure that it’s been set properly in the Directional Light as well. The option for RayTraced Distance Field Shadows must be enabled. Use a lower setting for the Dynamic Shadow Distance under Cascaded Shadow Maps section so that you can get more quality over a lower distance for CSM shadowing. Distance Fields use a generated mesh for shadows beyond this CSM distance. If the shadowing from Mesh Distance Fields does not look correct you need to make sure that you have enough resolution on the mesh by using Show > Visualize > Mesh Distance Fields. If the quality is not there you can use the documentation here for more information.

The static mesh does not have to be set to Movable to use dynamic lighting for Mesh Distance Fields or with CSM shadowing. It is fine to leave it set to Static. This just sets its mobility, not the type of lighting it uses. In case there was any confusion about that.

I hope this helps get your started.

Tim

Hi Tim,
Thank you for such a prompt reply and sorry about my delayed reply I have been away! As you mentioned increasing the Shadow Cascades to 10 certainly helped, it wasn’t perfect but having then adjusted the AO I was able to get much clearer level of detail on small shadow that seemed to be washed out with indirect world lighting bounces. Thanks!