Export Options Reference

You can find the latest reference by Epic Games here: https://docs.unrealengine.com/5.2/en-US/exporting-unreal-engine-content-to-gltf/

Below you'll find the latest reference that was available by the time the plugin was shipped

General Options

Option	Description
Export Uniform Scale	Scales exported Assets to compensate for differences in units. The default value is 0.01, to convert from Unreal Engine's default unit of centimeters to glTF's default unit of meters.
Export Preview Mesh	When enabled, the glTF exporter exports the preview mesh for a standalone animation or Material Asset.
Skip Near Default Values	When enabled, the glTF exporter does not export floating-point-based JSON properties that are nearly equal to the default values specified in the glTF specification or the specifications for glTF extensions. This reduces the size of the exported JSON data. Skipped properties are treated as though they're set to their exact default values.

Material Options

Option	Description
Export Proxy Materials	When enabled, the glTF exporter checks whether each exported Material has a glTF proxy Material defined in its user data. If it does, the exporter exports the proxy instead of converting the original material. This setting does not affect glTF proxy Materials you reference directly, the way you would any other material. For more information, see glTF Proxy Materials.
Export Unlit Materials	When enabled, Materials that use the Unlit shading model are exported correctly. The glTF exporter uses the KHR_materials_unlit extension to export Unlit materials. For more information, see Shading Model Support.
Export Clear Coat Materials	When enabled, materials that use the clear coat shading model are exported correctly. The glTF exporter uses the KHR_materials_clearcoat extension to export clear coat Materials. Some glTF viewers do not support KHR_materials_clearcoat. For more information, see Shading Model Support.
Bake Material Inputs	Specifies whether to bake a Material into a texture, and if so, how to bake it. Disabled: Never use material baking and only rely on material expression matching. Simple: If a material input needs baking, then only use a simple plane as mesh data. Use Mesh Data: If a Material input uses mesh-specific data such as vertex color, world position, vector transform nodes and so on, this setting includes that data in the Material baking process, and the resulting texture. For materials that don't use mesh-specific data, the exporter uses a simple plane. The exporter only uses baking for complex material inputs. For simple texture or constant expressions, it uses Material expression matching. For more information, see Material Baking.
Default Material Bake Size	When Bake Material Inputs is enabled, this setting specifies the default size of the baked texture that contains the Material input. You can override this default setting with Material-specific and input-specific bake settings. For more information, see the following sections: Configure Global Material Bake Settings for Specific Inputs. Configure Asset Specific Material Bake Options.
Default Material Bake Filter	When Bake Material Inputs is enabled, this setting specifies the default filtering mode used to sample the baked texture. You can override this default setting with Material-specific and input-specific bake settings. For more information, see the following sections: Configure Global Material Bake Settings for Specific Inputs. Configure Asset Specific Material Bake Options.
Default Material Bake Tiling	When Bake Material Inputs is enabled, this setting specifies the default addressing mode used to sample the baked texture. You can override this default setting with Material-specific and input-specific bake settings. For more information, see the following sections: Configure Global Material Bake Settings for Specific Inputs. Configure Asset Specific Material Bake Options.
Default Input Bake Setting	Input-specific default bake settings that override the general defaults. For details, see Configure Global Material Bake Settings for Specific Inputs.

Mesh Options

Option	Description
Default Level Of Detail	Default LOD level used to export a mesh. You can override this setting with Component or Asset settings. For example, a minimum or forced LOD level. For more information about how to control which LOD setting the glTF exporter uses, see Level of Detail (LOD).
Export Vertex Colors	Specifies whether to export vertex colors. If you set Bake Material Inputs, in the Material Options, to Use Mesh Data, the exporter bakes vertex colors automatically for any Material that needs them. The glTF format always uses vertex colors as a base color multiplier, which often produces undesirable results. We recommend disabling this option in most cases.
Export Vertex Skin Weights	Specifies whether to export the vertex bone weights and vertex indexes of Skeletal Meshes, which are required for animation sequences.
Use Mesh Quantization	When enabled, the glTF exporter uses quantization for vertex tangents and normals. This setting uses the KHR_mesh_quantization extension, which might cause the Mesh to not load in some glTF viewers. For more information about mesh quantization, see Mesh Quantization for High Quality Lighting and Reflections, and the KHR_mesh_quantization documentation.

Animation Options

Option	Description
Export Level Sequences	Specifies whether the glTF exporter exports Level Sequences. It only supports transform tracks. The exported Level Sequence plays at the Level Sequence Asset's Sequence Display Rate (frames-per-second setting).
Export Animation Sequences	Specifies whether the glTF exporter exports a single animation Asset used by a Skeletal Mesh Component. If you enable this setting, you must also enable Export Vertex Skin Weights in the Mesh Options.

Texture Options

Option	Description
Texture Image Format	Specifies the image file format to use for exported textures. None: The exporter does not export any textures. PNG: The exporter always exports textures as .png files. JPEG (if no alpha): The exporter exports textures that do not have an alpha channel as .jpeg files. If a texture has an alpha channel, the exporter exports it as a .png file instead.
Texture Image Quality	Specifies the level of compression for textures exported in a lossy image format. You can set values between 1 (least compressed) and 100 (most compression). Set a value of 0 to use the default compression level for the format. For .jpeg files, 0 is equivalent to the default value of 85.
Export Texture Transforms	When enabled, the glTF exporter exports UV tiling and un-mirroring settings in a Texture Coordinate expression node for simple Material input expressions. This setting exporter uses the KHR_texture_transform extension.
Adjust Normalmaps	When enabled, the glTF exporter flips the direction of the green channel in normal maps to conform to the glTF convention.

Scene Options

Option	Description
Export Hidden In Game	Specifies whether to export Actors and Components that are set as hidden in-game.
Export Lights	Specifies whether to export directional, point, and spot light Components. This setting uses the KHR_lights_punctual extension.
Export Cameras	Specifies whether to export Camera Components.

Variant Sets Options

Option	Description
Export Material Variants	Specifies whether and how to export material variants that change the Materials property on a Static or Skeletal Mesh component. None Simple Use Mesh Data