Problems with shading.

Saldations to all!
I am having persistent problems with lighting in the UE4 (4.14.3). In my project there are many lights, practically all static and half of these lights are with static shadows attached, the other half without shadows to save processing. I’m noticing that when my project becomes more complex many of my shadows disappear after compilation. I raise the mesh lightmap and the “lighting - overriddem map res” function and it is not solving the problem. Many shadows are imperfect and weak and others do not appear. In short, some shadows work well, others are imperfect and some do not appear even with proper lightmaping of the meshes (using the lightmap density tool - green color). In addition, these problematic lights illumine objects after compilation, they are very weak.

Can you post some screenshots?

Follow the screenshots. Note that the power of the lights are very weak, even at maximum intensity. In another example, the point does not generate light. There are 3 problems in fact, it does not illuminate, it illuminates precariously and when it produces light it has no shadow. This is repeated in various lights of the project.

It looks like you may need to switch to more dynamic lighting system, a lot of the shadows are too low of a resolution which may be due to having a large mesh/map

I also tried with stationary light, and the lights behave in the same way. Observing one of the examples of the screenshot, where 2 chairs appear, the mesh of this floor is small and well calibrated, with good resolution and correct Uvs, I do not understand why the spot light static does not properly illuminate the chairs (also well calibrated) and does not shade properly. In another image, you see a point light in a garden, without producing light. Could it be some lightmass setup?


I think it would be “impossible” to get proper shadows in a large scene like this with lightmaps… you can’t set a resolution as high as would be needed (and you’ll get those abstract looking incorrect shadows)… or you’d have to break up everything into modular pieces… IMO!!
I would go with stationary directional light with the help of cascaded shadow maps…

Also a silly question: all your screenshots say the light is not built… do you get the same results after building the light (preferable not in preview mode)?

Any change into lights requires building lights again (except with moveable lights). It seems they were never built.

Yes, the lights were built. When I did the screenshot, something had changed in the project, so UE4 requested a new construction.
In all confidence, I say that the results presented are after the construction of the lights.
Makiguiri, I conclude from your explanation, that large and complex scenes will always face difficulties in obtaining perfect lights and shadows?
Why does this occur in UE4? GPU? Processing, ram memory or a motor deficiency?

No!!! What I meant was to have precise shadows in a large scale like this you would have to have a HUGE/LOT of lightmap resolution… which I called impossible… this is why I suggested another direction…
Why this occur in UE4? …bad lighting setup… sadly I’m no expert in outdoor lighting…

I will answer, but Makigirl Im sure will say the same, as she has a lot more experience than me, but the problem with large scenes has to do with physics of light. Unreal and other engies, not to mention systems based on the same approach, they cast fotons whose amount will vary depending on the type of lights being used and their intensity. These cast fotons will travel and when they find an obstacle they will bounce according with the material properties at the place they hit, sometimes they scatter, sometimes just a few since some are absorved. That said, in a contained small scene is fast to place few light in strategic spots and quickly get results. The problem with large areas, is that those fotons will disperse more, so you will get those effects where the lights seen to not cast strong shadows (which are never pure black, but a dark shade in fact) because those shadows are receiving fotons from other contributing lights, making them even lighter than you wish.

This is the explanation, others might want to contribute with a direct solution for your problem, but I will link below one of the most complete threads about the subject you will ever find, and maybe there you will get even more information.…g-like-that-)==)

PS: lol, she answered right before me :wink:

Nilson, the link indicated is sensational indeed. Seeing his curriculum, I feel like a hero having to unravel all these mysteries of illumination in the UE4, therefore, I count on you always to help me in this way. I have not had difficulties in the external illumination daylight when I use only a light (sun), so I do not have problems with shadows, however large the scene. What complicates it are the night scenes, as in my project, which require dozens of lights, even if most of them are shadowed.
I can not settle for having inefficient lights in my project, I will continue the search for a technical solution to my problem. The way is open to questions.

There is this link inside documentation which is interesting:…tingScenarios/

and if you notice where the link is found inside documentation, you will see that there are other links with the lighting subject. I guess, until you can read and see which one will fit your purpose, you will take some time, but at least into the right direction.

I hope you share here what the solution was adopted, so others can benefit with your experience!


PS: I will try to find an article about distance field shadowing which was used in Fortnite, sec

I will post it as soon as it is resolved and thank you for all the attention and patience.