Our first experience
This study is on purely personal practice. There may be some unclear points and inaccuracies from the author himself. Hope to receive sincere contributions from readers.
Lumen – new lighting system
Lumen is Unreal Engine 5’s new fully dynamic global illumination and reflections system that is designed for next-generation consoles. Lumen is the default global illumination and reflections system in Unreal Engine 5. It renders diffuse interreflection with infinite bounces and indirect specular reflections in large, detailed environments at scales ranging from millimeters to kilometers.
Lumen is enabled through the Project Settings under the Rendering > Dynamic Global Illumination category. Set Dynamic Global Illumination Method to Lumen. This property also sets the Reflection Method to Lumen, and enables Generate Mesh Distance Fields which is required for Lumen’s Software Ray Tracing mode.
SET UP GLOBAL ILLUMINATION FOR THE PROJECT
Thankfully, with this new Lumen lighting system, we no longer have to waste time to build the lighting and get any problem from this process.
For creating an exterior lighting scene, with new advance of Lumen, I just simply used a DirectionalLight (1) and a SkyLight (2) with a HDRI image on it. Aside, I also added one sphere StaticMesh (3) as a Skydome which is showing a HDRI I want to indicate.
Notice, all the Lights in Lumen need to set to ‘Movable’ option in other to perform it correctly.
When we add a HDRI to our SkyLight. Under the Details, remember to Uncheck Lower Hemisphere Is Solid Color in order to show Reflection properly.
Something I noticed from this new Lumen method:
- The parameters from World Setting will not affect our Lumen lighting setting.
- Reflection Box and Sphere reflection will not work on Lumen.
With Sphere reflection capture the reflection doesn’t show up well.
Without it the reflection seems a bit better.
On this exercise, I utilized DataPrep and DataTable that setted up before to convert all information from Archicad to Unreal Engine, which will help to convert some certain Archicad materials to high-res Unreal materials.
Refer this link for DataPrep article.
After committing to Unreal Engine World.
Limitations of UE5
The Lumen reflecting solution appears to take HDRI information from SkyLight to represent an artificial reflection. Therefore, the reflection will not show properly of the surrounding.
For example, these glasses don’t show correctly the reflection of the interior. Instead, it shows the HDRI of the SkyLight.
Another example, the reflection of the table’s surface doesn’t show the ceiling, but the sky. Also, it doesn’t show the shadow of the candle and the cup.
Aside from that, the mirror is also an issue that need to be improved on this version. It seems way far worse than Ray-tracing method.
Unreal Engine 5 doesn’t support some of the previous version’s assets, include the Twinmotion’s materials.
RECTANGULAR LIGHT/ SPOT LIGHT
For some night testing renders, the shadows of these lights didn’t show properly.
And even in the daylight, DirectionalLight comes up with some errors.
To fix this issues, depending on each project we can touch these parameters under the details tab of the Lights:
- Shadow bias.
- Shadow Slope Bias.
- Shadow Filter Sharpen.
- Contact Shadow length.
Here are 2 examples of the values I used in 2 cases:
The results is not really that perfect but it could be enhanced a bit.
In order to successful package project, make sure that your Computer have Visual Studio and .NET installed.
You can refer to the download links below:
Visual Studio: Link
After install all the required software. We need to copy the “hostfxr.dll” file in:
(important to COPY, not MOVE!)
When you try to package your Windows project in UE5 now, the editor will still throw up a message and warn you in general that you do not have the proper SDK installed. Just ignore the message. This is most likely a bug. Your game will still package without any issues if you click “Continue” when the message pops up!
Another way, will be a bit manual but will optimize your file a bit:
Go to Platforms, Project Launcher:
Add a Custom Launch Profile:
- Project: Any Project
- Build: Shipping
- Cooked Platform: Window
- Cooked Cultures: en
- Cooked Map: Check all the maps you want to cook.
- Choose a path for Packaging on your computer.
Then go back and hit Launch this profile button. And then wait for the project for cooking.
Below is a cooked file of our project. You can download it and have a tour around. It would be great if you could drop some comments after seeing it.
Thank you very much for your time. Hope you enjoy the post.