Getting Content into your Unreal Engine 4 Pipeline
Getting your content into UE4 can be one of the most initially confusing and challenging aspects of learning to use UE4. Learn how UE4 imports and processes 2D and 3D content from other applications and get some ideas how to integrate that into your existing pipelines.
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Getting your existing scenes and content into UE4 is likely one of the first things you want to do after the Editor is running. It might also be your first major roadblock, especially if you’re looking to convert large, existing ray-traced visualization scenes over to UE4. By understanding what you need to do to prepare your content for UE4, you can save a huge amount of time by doing it the “Unreal way” the first time and get the quality and performance you and your clients expect from Unreal Engine 4.
Content Pipeline Overview
You’re probably used to working in a 3D application with an integrated modeler, material system, and renderer. After your data is in your 3D application, you can render your scene with a push of a button. You apply materials and lighting, create animations, and build your stories using the tools in your chosen 3D application. You might prepare textures and other data in external applications, but you do most of your day-to-day work in the 3D application of your choosing.
After your image or animation is rendered, you then load your image(s) into a post-editing application to add effects and titles, edit footage, and add audio. When it’s complete, a final version is rendered to a video or image file and shared with your audience or client (see Figure 3.1).
Figure 3.1 Traditional visualization workflow
UE4 is a standalone application and doesn’t integrate directly into any 3D application. Instead, you use 2D and 3D applications to produce 3D models and textures that you must export to an exchange format (FBX, TGA, and so on) and import into UE4 (see Figure 3.2).
Figure 3.2 UE4 visualization workflow
After import into UE4, you build your worlds within the UE4 Editor: adding lighting, materials, and interactivity. There is no Render button; the Viewport renders everything in real time, producing final-quality images including post-processing effects like motion blur, depth of field, and color grading.
To add interactivity, you use Blueprints, C++, and Unreal Motion Graphics (UMG) to create user interfaces and other onscreen titling. Sequencer allows you to create Hollywood-quality cinematics using a non-linear editor, physically based cameras, and camera rigs.
After the project is complete, you can deliver your application on any number of platforms: Mac, Windows, VR, mobile, and so on. You can also render high-quality stills and animations.
Take extra care when preparing content for use in UE4. Proper naming conventions, Lightmap UV coordinates, collision, LODs, and more are required to ensure a smooth, fast workflow, high performance, and quality rendering. Because there’s so much more to do to prepare your scenes, automation and consistency are essential for keeping production nimble, keeping your project stable and performant, and keeping production costs down.
The UE4 workflow uses a lot more artist time than raytracing. Why? Remember those insanely fast render times (.016–.033 seconds per frame discussed in Chapter 1) One of the best ways of making things render faster is to do the processing work ahead of time and store it in various ways. Baking in lighting, recording details using normal maps, or even the lowly act of assigning UVW coordinates all free up processing resources.
The upside is that your downtime during the UE4 workflow is almost zero. Exporting, importing, and processing data in UE4 is very fast. The only processes that take extended periods of time are typically threaded and can run in parallel with the Editor, allowing you to continue working in-Editor while you bake lighting or compile the project to run on a different platform.
You’ll also not be spending huge portions of your day waiting for renders. The Viewports in Max and Maya are notoriously terrible for conveying what the lit, rendered scene will look like, often failing to even show materials and textures properly. This forces you to render your scene to preview each of your changes, taking minutes, sometimes hours to get a good idea of how your final image will look.
UE4 is also fast at loading content. The Content Browser opens assets and previews them in real time, and the various editors open quickly even with complex content. Massive levels save and open in seconds, not minutes. The result is an interactive workflow that means you can do more in less time, and if you follow some simple guidelines, a lot of the work will be taken care of for you through automation and other magic.