Model Importer: Model

Model files that are placed in the Assets folder in your Unity project are automatically imported and stored as Unity Assets.

A model file can contain a 3D model, such as a character, a building, or a piece of furniture. The model is imported as multiple Assets. In the Project window, the main imported object is a model Prefab. Usually there are also several Mesh objects that are referenced by the model Prefab.

A model file can also contain animation data, which can be used to animate this model or other models. The animation data is imported as one or more Animation Clips.

Import settings for Meshes

The Import Settings for a model file is displayed in the Model tab of the FBX importer’s Inspector window when the model is selected. These affect the Mesh and its Normals. Settings are applied per Asset on disk, so if you need Assets with different settings, make (and rename accordingly) a duplicate file.

Property		Function
Meshes
Scale Factor		Unity’s physics system expects 1 meter in the game world to be 1 unit in the imported file. If you prefer to model at a different scale then you can compensate for it here. Defaults for different 3D packages are as follows: .fbx, .max, .jas, .c4d = 0.01 .mb, .ma, .lxo, .dxf, .blend, .dae = 1 .3ds = 0.1
Use File Scale		Tick the checkbox to use the default model scaling, or untick to use a custom scaling value for your model. Unity’s physics system expects 1 meter in the game world to be 1 unit in the imported file. If you prefer to model at a different scale then you can compensate for it here.
File Scale		Use this value field to set the scale you want to use for your model.
Mesh Compression		Increasing this value reduces the file size of the Mesh, but might introduce irregularities. It’s best to turn it up as high as possible without the Mesh looking too different from the uncompressed version. This is useful for optimizing game size.
Read/Write Enabled		If enabled, Mesh data is kept in memory so that a custom script can read and change it. Disabling this option saves memory, because Unity can unload a copy of Mesh data in the game. However, in certain cases when the Mesh is used with a Mesh Collider, this option must be enabled. These cases include: - Negative scaling (for example, (–1, 1, 1)). - Shear transform (for example, when a rotated Mesh has a scaled parent transform).
Optimize Mesh		Tick this checkbox if you want Unity to determine the order in which triangles are listed in the Mesh.
Import Blendshapes		Tick this checkbox if you want Unity to allow BlendShapes to be imported with your Mesh.
Generate Colliders		If this is enabled, your Meshes are imported with Mesh Colliders automatically attached. This is useful for quickly generating a collision Mesh for environment geometry, but should be avoided for geometry you are moving.
Keep Quads		Unity can import any type of polygon ( triangle to N-gon ). Polygons that have more than 4 vertices are always converted to triangles. Quads are only converted to triangles if “Keep Quads” is off. Quads might be preferable over polygons when using Tessellation shaders. See documentation on Surface Shader Tessellation for more information.
Weld Vertices		Tick this checkbox to combine vertices that share the same position in space. This optimizes the vertex count on Meshes by reducing their overall number. This checkbox is ticked by default. Note that there is also a WeldVertices parameter on the ModelImporter class, which does the same thing via scripting. In some cases, you might need to switch this optimization off when importing your Meshes; for example, if you have constructed your Mesh in such a way that you intentionally have duplicate vertices which occupy the same position, and you want to use scripting to read or manipulate the individual vertex or triangle data. .
Import Cameras		Tick this checkbox to import cameras from your .FBX file
Import Lights		Tick this checkbox to import lights from your .FBX file
Swap UVs		Tick this checkbox if lightmapped objects are picking up the wrong UV channels. This swaps your primary and secondary UV channels.
Generate Lightmap UVs		Tick this checkbox if you want Unity to create a second UV channel to be used for Lightmapping. See documentation on Lightmapping for more information.
Normals & Tangents
Normals		Defines if and how normals should be calculated. This is useful for optimizing game size.
	Import	Default option. Imports normals from the file.
	Calculate	Calculates normals based on Smoothing angle. If selected, the Smoothing Angle becomes enabled.
	None	Disables normals. Use this option if the Mesh is neither normal mapped nor affected by realtime lighting.
Normals Mode		Define how the normals are calculated by Unity. This is only available when Normals is set to Calculate.
	Unweighted Legacy	The legacy method of computing the normals (prior to version 2017.1). In some cases it gives slightly different results compared to the current implementation. It is the default for all FBX prefabs imported before the migration of the project to the latest version of Unity.
	Unweighted	The normals are not weighted.
	Area Weighted	The normals are weighted by face area.
	Angle Weighted	The normals are weighted by the vertex angle on each face.
	Area and Angle Weighted	Default option. The normals are weighted by both the face area and the vertex angle on each face. This is the default option.
Tangents		Defines if and how tangents and binormals should be calculated. This is useful for optimizing game size.
	Import	Imports tangents and binormals from the file. This option is available only for FBX, Maya and 3dsMax files and only when normals are imported from the file.
	Calculate	Default option. Calculates tangents and binormals. This option is available only when normals are either imported or calculated.
	None	Disables tangents and binormals. The Mesh has no Tangents, so won’t work with normal-mapped shaders.
Smoothing Angle		Sets how sharp an edge has to be in order to be treated as a hard edge. It is also used to split normal map tangents.
Split Tangents		Enable this if normal map lighting is broken by seams on your Mesh. This usually only applies to characters.

Light and Camera import

Cameras

The following Camera properties are supported when importing Cameras from an .FBX file:

• Field of View

• Projection mode ( Orthographic or perspective )

• Near plane distance

• Far plane distance

Lights

The following light types are supported:

• Omni
• Spot
• Directional
• Area

The following light properties are supported:

• Intensity
• Color
• Range (the FarAttenuationEndValue is used if UseFarAttenuation is enabled)
• Spot Angle (spot lights only)

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• 2017–09–04 Page amended with limited editorial review

• 2017–12–05 Page amended with limited editorial review

• Existing (pre Unity 5.6) functionality of Keep Quads first documented in User Manual 5.6

• Normals Mode, Light and Camera import options added in Unity 2017.1 NewIn20171

• Materials tab added in 2017.2 NewIn20172