How can I get clean fully dynamic lighting with LOD?

I’ll try to explain the best I can I have searched everywhere for an answer so hopefully someone here can tell me what they know or direct me to where I can find an answer. I am creating an outdoor scene and I want there to be absolutely no pre-computed lighting whatsoever. Please don’t tell me about how baking lighting is better and is more efficient. I want to light everything on stage with a dominant directional light that only casts crisp dynamic shadows. When you first start a default scene and place an object it has a great dynamic shadow with LOD as you move away from it. If you tell the light to be movable it disables this shadow system and instead places the cascade shadow maps that look extremely low quality. The only way to increase the quality is to reduce the dynamic shadow distance but this creates an unwanted effect of making the shadow disappear when you move away from it instead of just decreasing it’s quality. The only way to make the dynamic shadow look crisp is to make the dynamic shadow distance really tiny but then you have to be right on top of it to see anything. I want the shadows to appear everywhere on the map. So my basic question is how do I tell a dominant directional light to give off high res dynamic shadows with LOD as you move away? Then I want to create a skylight and make the shadows look softer and not stark black. Thank you so much for reading this and helping me out.

-John

Some tips to get crisper dynamic shadows over larger distances:

  • Increase Num Dynamic Shadow Cascades to 4
  • Increase distance
  • Increase Shadow Filter Sharpen

And that is with a dominant movable directional light with no pre-computed lighting? You created a large landscape, modeled some quick mountains and added the light?

Correct and adjusted the settings as such:

  • Distance: 80,0000
  • Num Dynamic Shadow Cascades: 4
  • Shadow Filter Sharpen: 1.0

The first picture is with the default scene just dragging in an asset from the library the lighting is great to me it’s a crisp dynamic shadow.

The second one is making the ddl movable and turning on cascade shadow mapping. It’s really weird looking and low res, shadow map number at this point is 3.

Next picture is increasing the shadow filter sharpen to 1.0 which makes the weird blob really sharp but still very low res.

The final picture is increasing the dynamic shadow distance to 80,000 which makes the shadows completely disappear.

How can I make them like the first on all objects in the level with LOD when you’re fr away and fully dynamic. A great example of what I want to achieve is in GTA5 and TESV: Skyrim they have crisp fully dynamic absolutely no baked shadows and it looks fantastic. That must be possible with UE4.

To get the same visual fidelity from your shadows as GTA V and Skyrim, your probably going to have to consider writing a different shadowing solution. The cascaded shadow maps in UE4 are good at shadowing large objects such as terrain over large distances, or small objects over small distances, but has issues combining the two.

I have put this onto my list of things to investigate and possibly code up some alternatives.

I’m just an artist I have absolutely no programming experience. So are you saying this type of shadow system is not built into UE4 it would have to be modded or some such?

Ok I think I solved my own problem by accident and the solution is so simple that I feel embarrassed. If you select the static mesh and make it movable and select the dominant directional light and make it stationary it will not bake the shadows of the object and instead only give it dynamic lighting with LOD. I rebuilt my lighting added a skylight and it looks fantastic. With the foliage tool it still does the same thing dynamic shadows with no baked shadows. On a landscape you should probably use cascade shadow maps.

I am glad that you found a solution. Although it appears that even with stationary, you get nice crisp shadows up close, but still fade out to nothing in a very short distance. Also they have some strange shadowing on Modular Skeletal meshes. So just be wary of that. I will continue to investigate a fully dynamic long distance solution.

I see what you mean they do fade out completely over not that large of a distance and although it isn’t exactly what I wanted it works for no I suppose. Another solution would be amazing. Thank you for all your help I really appreciate it.

I also found that making the light completely movable and changing the cascaded shadows settings to a higher quality also helps me.