Datasmith Import Options

Sets the lightmap resolution for the Static Mesh Assets that Datasmith generates. These lightmaps are used to store lighting information per instance when you use precomputed lighting (Static and Stationary lights) in your Level.

Don't set this value too high on import. Set it to a good baseline level for your Project, then increase it for individual Static Mesh assets that need higher resolution to achieve good results when you build your lighting.

Determines whether or not Datasmith should generate lightmap UVs for each Static Mesh Asset it imports. This option is enabled by default, and is typically recommended to ensure that you'll be able to use baked lighting for all geometry that you import through Datasmith.

However, generating lightmaps automatically at import time has downsides. It takes time during the import process. It creates additional UV channels on your Static Meshes, which makes their memory size slightly larger. Finally, you have no direct control over the resulting lightmap.

You may be able to save time and memory by disabling lightmap generation if any of the following are true:

• You have already created UV mappings suitable for lightmap baking in your source application.
• You intend to use only dynamic lighting or ray tracing for lighting your scene in Unreal.
• You intend to generate your own lightmap UVs after import, using tools built in to the Unreal Editor.

See also Working with UV Channels and Understanding Lightmapping in Unreal Engine.

In order to use Static or Stationary lighting in the Unreal Engine, your models need to have lightmap UVs in which no two triangles overlap.

• Enable this option to have the Datasmith importer automatically generate these lightmap UVs for the Static Mesh Assets it creates. In order for this to work, your models need to have at least one non-empty UV set to start with. If a model does not have any UV sets at all, the importer will create a blank UV set for the Static Mesh Asset, but this blank UV set will not be usable for applying textures or lightmaps to the Static Mesh.

• If you've already created valid, non-overlapping lightmaps for the objects in your source application, you can leave this option unchecked to have the Datasmith importer skip creating new lightmap UVs. In this case, your Static Mesh Assets will use the UV set with the highest index as its lightmap UVs.

For more background information, see Working with UV Channels.

Determines the scaling factor the importer uses to convert linear distances. The default value of 100 converts from meters (as specified in the glTF specification) to centimeters (as used in the Unreal Engine). If your source scene uses a different unit of measurement than meters, adjust this value to the number of centimeters per unit.

Combines subtrees of StaticMesh nodes that are not used for animations, variants or other functionality into single StaticMesh nodes. This can make scene management in Unreal easier by reducing the depth and complexity of the scene hierarchy. However, this option is not recommended if you need to clean up your imported Static Meshes manually, or if your scene contains many instances of the same geometry.

If you disable this option, but leave the Import > Lights setting enabled in the common Datasmith properties, the lights that Datasmith creates in Unreal will contain only information stored in the .fbx file. If you enable this option, Datasmith imports extra information about the lights in your VRED scene from a .lights file that was created when you exported your scene. This carries over extra properties about your lights that are not supported by FBX, such as IES light profiles, and typically leads to better visual results that more closely match your lighting in VRED.

In order to use Static or Stationary lighting in the Unreal Engine, your models need to have lightmap UVs in which no two triangles overlap. 

• Enable this option to have the Datasmith importer automatically generate these lightmap UVs for the Static Mesh Assets it creates. In order for this to work, your models need to have at least one non-empty UV set to start with. If a model does not have any UV sets at all, the importer will create a blank UV set for the Static Mesh Asset, but this blank UV set will not be usable for applying textures or lightmaps to the Static Mesh.

• If you've already created valid, non-overlapping lightmaps for the objects in your source application, you can leave this option unchecked to have the Datasmith importer skip creating new lightmap UVs. In this case, your Static Mesh Assets will use the UV set with the highest index as its lightmap UVs.

For more background information, see Working with UV Channels.

Combines subtrees of StaticMesh nodes that are not used for animations, variants or other functionality into single StaticMesh nodes. This can make scene management in Unreal easier by reducing the depth and complexity of the scene hierarchy. However, this option is not recommended if you need to clean up your imported Static Meshes manually, or if your scene contains many instances of the same geometry.

In order to use Static or Stationary lighting in the Unreal Engine, your models need to have lightmap UVs in which no two triangles overlap. 

• Enable this option to have the Datasmith importer automatically generate these lightmap UVs for the Static Mesh Assets it creates. In order for this to work, your models need to have at least one non-empty UV set to start with. If a model does not have any UV sets at all, the importer will create a blank UV set for the Static Mesh Asset, but this blank UV set will not be usable for applying textures or lightmaps to the Static Mesh.

• If you've already created valid, non-overlapping lightmaps for the objects in your source application, you can leave this option unchecked to have the Datasmith importer skip creating new lightmap UVs. In this case, your Static Mesh Assets will use the UV set with the highest index as its lightmap UVs.

For more background information, see Working with UV Channels.