Architectural Scene Import with Datasmith: 5 Checks for Unreal Engine

When importing scenes created in design applications into Unreal Engine, Datasmith aims to transfer information such as scale, hierarchy and naming alongside geometry. Epic Games’ official documentation notes that the result may not always be an exact copy of the source scene, and that some aspects require separate review. These five steps summarize what to check before and after import for architectural presentations and interior visualization workflows. The documentation does not specify a single Unreal Engine version for these steps; supported design software versions and plugin details should be checked separately.

1. Confirm that the source application and import method are supported

First, check the version of the design application and how it connects to Datasmith. The official support table defines three methods: “Direct,” where Unreal Engine reads the file directly; “Export,” where the file is prepared using the application’s own export feature; and “Export Plugin,” which requires installing a plugin for the application. Knowing the file extension alone may not be enough; you need to select the correct method.

*According to a note in the documentation, starting with Unreal Engine 5.3, Autodesk manages new Revit export plugins, and the plugin is included with Revit 2024 and later. In addition, backward compatibility is not guaranteed across all versions of the Datasmith export plugins and Unreal Engine. Verify the Unreal Engine and plugin versions together for your project; don’t assume imports between different versions will work seamlessly.

2. Check scale and transformations in the hierarchy

Unreal Engine evaluates scene distances in centimeters. If the source application uses a different unit of measurement, Datasmith scales the scene to preserve real-world dimensions. So you don’t need to change the source scene’s units just to move it into Unreal Engine. In the example in the official documentation, an object that is 10 inches long in the source scene is shown as 25.4 world units long in Unreal Engine.

Although scale conversion is automatic, complex hierarchies can cause problems. Uneven scaling on parent objects, combined with custom pivot transformations on child objects that compensate for that scale, can result in imported positions that don’t match the source scene. If you see this discrepancy, consider simplifying transformations in the source application and importing the scene again. In particular, check that walls, floors and fixed furnishings are where you expect them to be.

3. Check normals and thickness on surfaces that disappear

For performance, Unreal Engine may not render surfaces facing away from the camera. If a single-sided surface with no thickness was used in the source application and its normal faces the wrong way, parts of the model may seem to disappear from certain angles. If a problem area is visible from another angle, check the surface orientation before concluding that the geometry failed to import.

1. Identify the angle from which the surface disappears; check whether it becomes visible again when viewed from a different direction.

2. If possible, give the surface thickness in the source application and confirm that its normals face outward.

3. If the surface should be visible from only one side, correct its normal direction in the source scene and import it again.

4. If you can’t return to the source model, consider flipping the triangle orientation in Static Mesh Editor; a subsequent Datasmith import may remove these edits.

A two-sided material can make a surface visible from both sides. If you’re using a Material Instance, the relevant option is in the Material Editor’s Details panel under General > Material Property Overrides > Two Sided. However, the documentation warns that this method can cause visual artifacts with Static or Stationary lighting. Since both sides use the same lightmap area, it may be more suitable to fix the source of the problem first rather than applying this option to all geometry.

4. Distinguish lightmap UVs from shadow settings

With static lighting, non-overlapping UVs are required to write light and shadow information onto mesh surfaces. Datasmith runs Unreal Editor’s automatic UV unwrapping system for every Static Mesh it imports. The system separates surfaces into UV islands, arranges them to prevent overlap, and sets up the generated second UV set for lightmap use. This automatic preparation doesn’t eliminate the need for visual checks after lighting the scene.

If the issue isn’t that a surface is invisible, but that light appears to pass through an object incorrectly, a different setting may be involved. The Static Mesh Actor’s Details panel includes Lighting > Shadow Two Sided; the documentation describes this setting for cases where an object needs to cast shadows from both sides. Don’t use the Two Sided material option for surface visibility and this shadow setting interchangeably.

5. Review names, physics and lights one last time

Datasmith tries to reuse names from the source scene wherever possible, but a Static Mesh label in the Content Browser, the name of the asset file on disk and the Actor name in the Level may not match. If the source application contains objects with the same name, duplicate labels may appear in the Content Browser; filenames on disk, however, must be unique. Duplicate Actor names in the Level may receive numerical suffixes. If your workflow accesses assets through Blueprint or Python, account for the possibility that the label and filename differ.

Physics settings are not configured by default for Static Mesh assets. If you need collision or physics, configure them in Unreal Editor after import. Lights can be imported from supported source files and converted to the appropriate Unreal Engine light types. Some area or volume lights in other applications have no direct equivalent in Unreal Engine, however, so check how imported lights behave in the scene.

Impact on architecture and visualization workflows

These steps are especially useful for architecture firms and visualization teams preparing large scenes from different design applications for presentation in Unreal Engine. Automatic scale conversion can reduce unit-related adjustments, while automatic UV generation handles part of the lightmap preparation. However, teams still need to assess complex transformations in the source scene, surface normals and certain light types.

Before getting started, check the design software version, the required export method, and whether the plugin and Unreal Engine versions are compatible. If you encounter problems with single-sided surfaces, fixing the geometry in the source is often safer than relying on Editor changes that may be lost during reimport. The benefit of these checks is not a promise about hardware requirements or import time—neither is specified in the sources—but a clearer understanding of where to look for problems.

Common mistakes

• Immediately changing the source application’s units when you notice a scale difference; Datasmith converts scale automatically.

• Assuming an invisible surface is an import error; check its normal and thickness first.

• Applying the Two Sided option to every material; this can cause artifacts with Static or Stationary lighting.

• Assuming surface edits made in Unreal Editor will remain after reimport; importing again from the source scene may remove them.

• Checking only the source application version and overlooking plugin and Unreal Engine compatibility.

• Trying to fix a visibility issue and a shadow issue with the same setting; the material option and Shadow Two Sided serve different purposes.