Ask Epic Anything: Lighting in UEFN | August 24, 2023 at 11AM ET

[lonnald]

@Wertandrew

Would love to get some post process materials added in UEFN with various customizable and professional-looking PP effects, like outlines, scanlines, nightvision, recorder cam, pixelated, vivid colors, degraded, 1930s cartoon, etc. This would really benefit beginner creators that want to prototype unique artstyles for their content. Similar to how the existing filters of Creative exist as PP volumes, but with more settings that allow more unique themes.

We do expose some PP effects in /Fortnite/Lighting/PostProcess, but you make a great point and shipping more effects, particularly those creators can learn from is a great idea. I’ll bring it up with the team. Thank you for the suggestion!

[lonnald]

@StellarLime911

Will we ever be able to use the skydome device in 2.0 islands? The day sequence device is much more limited, as you must use 1 set of settings for the entire day, rather than having different colored skies at different times, for example. The skydome device was also connected to channels/events, whereas the new one isn’t.

We do not have any plans to expose the Skydome device to UEFN. The Day Sequence device is intended to be its replacement. While we understand that the Day Sequence device does not yet have full parity with the former Skydome device, we are actively working to bring that up to par. For example, enable/disable events on the Day Sequence device will be coming soon.

[J_Lauf1]

@Wertandrew

Could you explain how fog works in day sequence device? I could never figure out the settings and how to make controllable fog based on height or distance, I usually just experiment until it works on a couple platforms.

The fog settings on the day sequence device directly correlate to the settings on the exponential height fog actor. Please refer to the Unreal docs on that component. For more control you can also disable the fog component using the day sequence device and place your own fog actor in the world.

[Carlos.Cristerna]

@DimensionDragon

What are the best lighting practices generally you recommend for good perfomance across platforms in UEFN?

Lighting is a complex issue specially when developing for different platforms. I would recommend that you start simple, use the tools provided with their defaults as they have been tuned to work as efficiently as possible. Try to get to your final look with as few lights as possible and constantly check scalabilities in the editor to see how your lighting is affecting all the game areas. once you are satisfied with the general look give it another pass at secondary lighting like Fill lights and accent lights there can also be a tertiary layer of self illuminated objects that will add visual complexity without too much expense. But this is just a very general philosophy. at the end of the day all projects are different and will require some trial and error.

[jon_eg]

@Chompster86

Any plans to add more items with lighting? There’s items like the flashlight, flashlight pistol, and the torch that illuminate, but I think more items that illuminate will be very helpful with expanding maps a little bit more. Some examples that came to my head are a flashlight assault rifle, an item to throw down those glow torches to light a path, and a glowstick sword.

While we are unable to comment on future plans, we do appreciate such questions as they help inform of us of your interests, so thanks for that!

[jon_eg]

@PixelandPoly

Are there plans to add ‘User Options - Functions’ such as Enable, Turn On, Turn Off, Dim Light, etc. to the built in UEFN lights the same way that the Customizable Light Device has?

I would include the Day Sequence Device in that list as well. It would be really helpful to have event access to those lights especially for those that are not using Verse yet.

While we are unable to comment on future plans, we do appreciate such questions as they help inform of us of your interests, so thanks for that!

[Carlos.Cristerna]

@Kiriousaurus

Will we ever be able to differentiate between lumen and non-lumen settings on lighting actors?

There are a few ways you can achieve this. If you are using The “Fortnite Time of Day Manager” / “Day Sequence Device” then that already has some under the hood controls to make it work in different platforms. However you could also use the “Lumen Exposure Manager” on top of the “Day Sequence Device” which contains 2 Post Process Volume ( Non Lumen post process and Lumen Post process) that will allow you to tweak your look depending on scalability but it will be more expensive post proces stack. If you are using the “Environment Light Rig” then you dont need to use the “Lumen Exposure Manager” since this device has included 3 Post proces Volume in it (Lumen Exposure, Basic Exposure and Color Grading). Last but not least is the “Lighting Scalability Manager” which is a device that can help you chose which lights and or meshes are used depending on scalability.

[jon_eg]

@Wertandrew

Any plans for supporting a toggle/control for the shadow that is created by inverted planes and normals (in FN TODM)? Sometimes I use this feature a lot to make various effects, other times I don’t want it at all, would love to be able to have a slider on the amount of shadow that is generated (only affects epic settings, use a snow pile FN prop to repro)

@Wertandrew

Any plans for exposing the TOD as a variable that verse can see and control? Like if its 15:00 that would be something that verse can see, so we can do events etc. Also the ability to control the TOD through verse (if that’s a thing already lmk, I haven’t dug too much to it so idk)

@Wertandrew

Atm TOD in UEFN is not showing the in game TOD but has a preview slider intead. Would love if there was a toggle button there to show the island setting TOD instead of the preview, especially for cases when its random or it moves.

@Wertandrew

Is there an accurate way to see what lighting looks like in Nintendo Switch? So far there is no setting combination or preview that shows exactly how it looks like and its hard when making atmospheric settings when one platform sees nothing (some auto exposure settings cause Switch to be super dark)

@Wertandrew

Any plans on supporting Lighting scalability managers with PP volumes, VFX creators, VFX spawners, Niagara particles and day sequence devices? I found that to be impossible with the current tools (and provided utilities, current lighting scalability manager doesnt disable/enable PP volumes, only toggles actor visibility on meshes, very limited functionality). VFX Creator effects create glitches on Nintendo switch and I tried using it to prevent them, but it didnt work the way I wanted it.

@Wertandrew

Any plans on having a consistent look for fog settings and PP effects on all platforms supported by FN? Or to allow us to control how the game looks on various platforms (see question 10).

While we are unable to comment on future plans, we do appreciate such questions as they help inform of us of your interests, so thanks for that!

[jon_eg]

@Crizon46

In the Environment Light Rig, could we have more customisation of volumetric clouds such as changing the height of them or placing/painting our own clouds?

@Crizon46

I saw a video about UE5’s color correct regions and I thought they were cool, could they be added to UEFN at some point?

While we are unable to comment on future plans, we do appreciate such questions as they help inform of us of your interests, so thanks for that!

[jon_eg]

@TOMLINSTUDIO2

Will it be possible to control the Day Sequencer Device using Verse code in the future, to manually change for instance time of day during a game?

While we are unable to comment on future plans, we do appreciate such questions as they help inform of us of your interests, so thanks for that!

(Sorry I sound like a broken record here!)

[TOMLINSTUDIO2 (TOMLIN STUDIO)]

Thank you! I am doing it but in a very different way right now, because I could not find a way to manually control the sky using Verse in game.

[Carlos.Cristerna]

@Minos100T

Most of my questions were already asked, but here’s another one, what are these blotches in the ambient shadows when running the map in medium scalability settings? (without lumen) They seem to be related to the skylight. Also noticed in normal Unreal 5.2 maps when turning off lumen.

In medium scalability, Lumen Global Illumination is off. So, what you see is distance field Ambient occlusion.

Here are a few general suggestions to take into consideration that I noticed other people had issues with too.

In medium scalability, Lumen Global Illumination is off, so you are left with Distance Field Ambient Occlusion. when you are creating geometry from scratch using the modeling tools, especially with Boolean operations try to not to make them too large in size. the simpler the meshes the better. IF you have a mesh that is too large or is not a closed mesh (air tight)with all its welded vertices and edges you will find some of these undesired effects. Try to split the mesh into smaller chunks and see if that helps. Inspect the mesh with the modeling tools and see if there are any un welded edges.

[J_Lauf1]

@iamHasimTTV

is epic planning to add a feature to the lighting to change the intensity seperatly. lumen and non lumen. so we can make the lightning look the same both on dx11 and dx12.

thanks

I'm unable to comment on future plans, however as a work around you can use the lighting scalability manager to toggle visiblility of lights based on global illumination scalability. You would want to make sure your lumen light is set to high and above and your non-lumen light is set to medium and below.

[jon_eg]

@II-REAXE-II

How to calculate lightning memory (uefn lights not Spot light from 1.0)

Lights from the “Lights” menu under the + menu in the toolbar don’t affect GPU memory in any significant way, but they do affect speed, especially if they have shadows enabled.

[jon_eg]

@Wertandrew

Any plans on enabling the stencil buffer so we can bring PP effect to the next level? I know a lot of creators have been asking for that feature (and if there is a toggle setting to enable that on the player too, from island settings, that would be perfect).

Thanks for the feedback, it’s something we are thinking about too. The issue with stencils currently is that they could potentially conflict with stencils used by some characters, or possibly other Fortnite materials in the scene.

[StellarLime911]

When lumen is disabled, my jungle landscape material has orange patches of grass in the top left corner of my island. Why is that?

[jon_eg]

@JoeriDukker

What does the Light Renderer actually do in Niagara. I was expecting like a glow effect but nothing changes when I tried to use it.

The light renderer creates a light at each position. Its effect would be to light other things. It can be used either at the emitter level (one per emitter, most common, say the core of an explosion) or per particle.
The lights are considered “Simple Lights” and are cheaper than a light component and mostly cost overdraw/pixel fill and don’t typically cast shadows. They also typically don’t have exponental falloff which bounds their radius of pixel influence better than inverse square.
The feature needs to be used with care since it can quickly get expensive and the guidance is always to use sparingly.

[jon_eg]

@Crizon46

Can lighting be used in any way with Niagara?

Niagara supports lit particles, as long as the shader is in lit mode, and can be per vertex directional, nondirectional, or per pixel. Niagara sims can also cast shadows.

[jon_eg]

@ImerzaChristo

At Imerza we create digital twins of real-estate and industrial applications. Adding a lighting control feature for inside a condo unit while closing the window shades is on our roadmap. We would include dimming as well as a selection of different color temperatures. While doing this in a general and high-level way is achievable, I’d like to learn more about best practices to create extremely accurate visualizations of existing lighting products.

Hi, this sounds like fascinating work! I just wanted to point out that this AMA is focused on Unreal Editor for Fortnite (UEFN). I’m not sure if you are interested in doing this work in UEFN, or regular Unreal. UEFN currently has a more limited feature set than Unreal, so the answer might be different depending on which you are considering.

@ImerzaChristo

IES: Unreal allows for IES file imports but you have to match it with one of the limited form factors such as a point light or omnidirectional. How would a tape light or linear fixture IES file be accurately applied to one of the existing profiles or is there another way?

It looks like Rect Lights (aka area lights) in Unreal/UEFN do support IES profiles, but I don’t know if it would apply in a physically accurate way for a long tape light for example. Large or long area lights in general have limitations in real-time renderers since they are difficult to cast accurate shadows from in real-time.

@ImerzaChristo

Lighting designers and architects rely on lighting calculations to trust that simulations are accurate. The industry standard has been AGI32 for years. Are there plans to be able to perform lighting calculations in Unreal?

I am not familiar with AGI32. However Unreal lights do support physical units – lux/lumens/candelas depending on the light type. There is more documentation about it here: Using Physical Lighting Units in Unreal Engine | Unreal Engine 5.2 Documentation