Convert a Corona project render to Unreal Engine
Discover the fantastic world of real-time rendering that is revolutionising the industry
Pixomondo’s senior 3D environment artist Bell Rodrigo provides a handy step-by-step guide to converting your scenes to Unreal Engine
For a long time, 3D professionals used offline renderers as the only working tool, but now with the advancements in real-time rendering, and the launch of LED used in the TV series
The Mandalorian, there has been a huge explosion in the use of Unreal Engine by VFX professionals. Recently with the release of Unreal Engine 5, which has already dominated a good portion of the gaming market, the software promises to strongly embrace the big screen, creating photorealistic scenarios and in record time.
In this tutorial, Pixomondo's senior 3D environment artist will demonsrate how to convert your traditional 3ds Max and Corona Renderer scenes to Unreal Engine. You will learn how to convert a 3ds Max scene to Unreal Engine with realtime rendering, without losing photorealism, and will gain the flexibility of Unreal Engine's raytracing, which can be used in the creation of architecture, VFX and games.
01 MODEL IN 3DS MAX
To begin we need to model our environment in a software like 3ds Max, Blender, Maya, Revit or Sketchup. It’s important to try to optimise our models to reduce the maximum amount of polygons, because Unreal Engine is a game software. We must consider optimisation at all times; reduce faces and delete areas that will not be seen in the project, for example the back of a bed that will be leaning against the wall.
02 UV FOR TEXTURES AND LIGHT MAPS
We have to work with the UVS so that they are placed evenly on our objects, to facilitate texture IDS in each region of the model. Also, it is important to open the UVS so that one is to place our textures and the other is to receive light in Unreal Engine. You can do this manually, or there are plugins (paid and free) available for this purpose. In addition to UVS, it is important to apply textures to objects, on each separate surface. In this step we apply all textures in our
environment, which can then be exported to Unreal Engine. It's important to put the texture at one metre by one metre, so that when we use it in Unreal it will better adapt to the Unreal Engine system.
03 EXPORT TO UNREAL ENGINE
Here you can export your project in two ways. One method is directly in 3ds Max with FBX format, the other way is by installing the Epic Games plugin, called ‘Datasmith’, which allows you to generate a more optimised model for Unreal. You can download it for free from the Epic Games website, depending on the version of software you are using. It's important to point out that although Datasmith helps with the export, it won't leave it as optimised as if done manually.
04 IMPORT THE MODEL
As in 3ds Max, in Unreal Engine there are two ways to import your project, the first one is using FBX format where you just drag the model into Unreal Engine.
The other way is through the aforementioned plugin Datasmith, which imports the models with the UVS and textures in an automated fashion. This is the fastest but not always the most satisfactory process, so I recommend testing both methods to see which works best for you and your project.
05 FIX THE MODEL’S SCALE
Unreal Engine uses centimetre models; if your model comes out of the correct unit, you can scale down the Transform bar.
It is important whenever using the models in Unreal to configure the pivot of each object in relation to the Unreal Engine world, otherwise you will have difficulty moving the object in the scene. A tip is to leave objects that don't need to be moved like walls, floors, and windows at the 0 position in 3ds Max, and for objects like furniture that are movable, put the axis on the object itself so that when you want to move it won't be difficult.
06 CONVERT CORONA MAPS TO UNREAL
In this step, we use the maps we have from Corona Renderer in
Unreal, like Normal, Base Color, Roughness and Metallic. Unreal uses the same node system as Corona Renderer. I like to make my maps in Corona, but you can create your textures directly in Unreal Engine – see what you prefer. Many artists use Megascans materials that you can download with the Bridge plugin.
07 APPLY MATERIALS TO FURNITURE
After creating our materials in Unreal, just drag to each object in our scene, for example this yellow colour that we use in the scene's closet. Now comes the fun part, where we apply materials in the scene and test how they behave on objects – it's important to define the UVS in 3ds Max, to avoid any problems in Unreal Engine.
08 ADD LIGHTS TO THE SCENE
One of the most important parts of Unreal's scenery are the lights, with which we can start to bring our project to life. I love lighting, it's one of the parts that attracts me the most, because it's where we define the mood of the project, be it day, night, sunset…
In this project we’ll use rectangular lamps to simulate external lighting. You can see the settings in the screenshots below: (a). The sunlight that will be
directed into the scene. (b). Here you can see the Directional Light settings. (c). Point lights are very useful for lamps, under TV lights, or simulating LED lighting. Here you can see their configuration – you can change the length, colour and power settings.
09 PLACE POSTPROCESSING VOLUME
Another important element is the processing volumes, where we will put all the processing energy and specific configurations for our world. We can edit reflections, shadows, exposures, etc.
This post-processing box acts like Photoshop inside Unreal, and enables us to define and configure different settings that will help us to achieve the highest possible quality for our project.
10 ADD CAMERAS
The cameras in Unreal Engine simulate real-life professional
cameras, and we can select and tweak the camera type, angle, lens type, depth of field and much more, to give life to our image.
Reflection spheres are visual effects that capture objects in the scene and adjust reflections on objects like metal and glass. I used them to reflect on the TV. This effect allows us to improve the reflections of our scene.
11 RENDER THE IMAGES
The time to render has come, you can choose which quality level you want in Unreal from the production preview. We then need to extract high-resolution images from the Unreal scene.
A tip: check the resolution number of each object in your scene, those that are between values of 1,024 and 512 are of good size; avoid accumulating a large number of resolutions that will make your project cumbersome.
Finally, Pixlr X was used for posting images – in addition to being free and online, this tool enables you to edit many aspects of your image in an intuitive and fun way. I like to use this app, but other post-production tools like Photoshop, Lightroom or Gimp may suit your preferences. •