A Simple Guide to Lighting for Twinmotion Architectural Rendering

Hello, my name is Eitan, and in this Instructable I am going to walk you through how I used Twinmotion to create an architectural render of an emergency response shelter, and how you can achieve perfect lighting for your own models. Let's get started!!!

For this project, I used the Twinmotion modeling and rendering software published under the Unreal Engine by Epic Games. I chose Twinmotion for the renders because it has a very simple interface compared to other programs like Blender, it has a great selection of assets from it's built-in library, and it it very flexible with file formats. Twinmotion also has very easy-to-use lighting settings and assets, so it's perfect for this project.

There are 100 different ways to create a 3D model, all with their own unique benefits and drawbacks. Since this project was about an emergency response shelter that was formed from a 20-foot shipping container, I knew the modeling would be technical and require precise dimensions and joint relationships. That's why I went with Autodesk's Fusion to model the base of the structure, with all of the main design components. Fusion is a super straightforward and easy-to-learn program that is crazy powerful for stuff like this, and I think the CAD model turned out awesome. Once I had my model fully finished, I exported all of the different components of my models as OBJ files from Fusion, and then imported them into Twinmotion using the "import mesh" tool.

A good render starts with a good background environment, as it serves as the basis for all of the lighting in the scene. Since the emergency response shelter would be deployed in a more rural setting, I wanted the background to represent the environment accurately. After deciding to portray the shelter in a grassy field, I started by creating a floor plane, and then added a 3D grass material. I then used the Paint tool to create the foliage. After adding some rocks, weeds, ornamental grasses, and a couple varieties of trees and bushes to the object painting list, I brushed a perimeter of foliage around the deployed shelter. I then picked the "Pink Sunrise" lighting environment, and set up HRDI for the sky. I really like the way that the final renders look with the trees and bushes in the background, and I think it gives a pretty good idea of what it will look like when deployed. I turned down the intensity of the environment to 0.5 because I wanted the lights inside of the shelter to cast shadows on the rest of the scene, and with the environmental light so high the rest was being washed out.

To provide the main lighting for the scene, I started to work on the interior of the shelter. As with my original outline, there are two LED light bars on either side of the shelter to provide light on the inside, as well as making the Red Cross symbols slightly emissive for easier visibility. Initially the LED bars were casting a little too much light on the scene, and because the container material was so reflective the light was too evenly dispersed for my liking. I raised the reflective index of the back wall material to cast a few more reflections for accuracy, and decreased the reflectiveness of the shipping container so the final images wouldn't be too noisy. I kept the temperature of the LEDs to a warm 4500K, to make the scene feel warmer and more friendly, rather than scary and sterile as medical offices usually are with their dull fluorescent lighting.

To bring the scene to life, I used the built-in Twinmotion asset libraries to create a scene of the shelter in use. On the right I made a nurse treating a patient on an operation bed, in the center a doctor working on the bench, and on the left two nurses pre-screening patients and assessing their medical conditions.

As I got ready to start the final renders, I set the parameters for how I wanted light to be rendered in the scene. I was faced with two options: real-time and path tracing. The first uses a game-engine style program to calculate the way light plays out in the scene, and while it can be much faster to render and simpler to manage, it's not as realistic. Path tracing on the other hand calculates light emitted from emissive sources in the model as millions of individual rays, bouncing off of different objects as they interact. Although the fans on my PC might have been loud enough to wake up the neighbors, path tracing was totally worth it. Above you can see the difference: the reflections of the bins on the floor, the glow of the Red Cross sign on the wall on the right, the higher-accuracy shadows on the figures. I set the amount of ray bounces calculated to two bounces, so that the final renders wouldn't be too washed out, and with that, I was ready to render!!!

This render shows an alternative configuration of the shelter, where it is used primarily for a patient waiting and diagnosis area.

I'm really happy with the way these renders turned out, and I think the lighting played a huge part! I think the way that the LED bars cast shadows out of the shelter onto the surrounding environment is awesome, and the path tracing really made it feel real. I know this isn't the longest tutorial, but I thought that it would be cool to share the lighting process for a rendering engine that gets a little less love, and for a unique architectural application. And I would love any suggestions on if there is anything I could improve, as I know I have a lot to learn and I'm sure with a little more expertise, these renders could be even more jaw dropping. Thanks so much for reading, and happy rendering!!!