Meshes
Reference Manual > Components > Asset Components > Meshes

Meshes

Meshes make up a large part of your 3D worlds. You don't build your meshes in Unity, but in another application.

In Unity, we have done everything in our power to make this process as simple as possible. There are a lot of details, but the following pages should address all specificities of the common 3D art packages:

Other applications

Unity can read .FBX, .dae, .3DS, .dxf and .obj files, so if your program can export to this format you're home free. FBX exporters for popular 3D packages can be found here. Many packages also have a Collada exporter available.

Textures

Unity will attempt to hook up materials to your imported scenes automatically. To take advantage of this, place your textures in a folder called "Textures" next to the scene file, or in any folder above it.


Place your textures in a Textures folder at or above the asset's level

Import settings.

To access the Import Settings for a 3D mesh file, the relevant settings options will appear in the Inspector.


The Mesh Import Settings dialog
Share MaterialsEnable this to generate material files near the found texture files. When enabled, different scenes will share the same material settings when they use the same textures. For the precise rules, see Material Generation below.
One Material for...This will generate materials per scene, so only this scene uses them.
Don't generate materialsThis will not generate materials at all.
Mesh Scale FactorUnity's physics system expects 1 meter in the game world to be 1 unit in the imported file. If you like to model at a different scale, this is the place to fix it.
Generate CollidersIf this is enabled, your meshes will be imported with Mesh Colliders automatically attached. This is recommended for background geometry, but never for geometry you move about. For more info see Colliders below.
Automatically calculate normalsEnable this to automatically generate normals for the imported geometry. If enabled, the Smoothing Angle sets how sharp an edge has to be to be treated as a hard edge. The smoothing angle is also used to split normal map tangents.
Split tangents across UV seamsEnable this if bumpmap lighting is broken by seams on your mesh. This usually only applies to characters.
Swap primary and secondary uv channelUse this if Lightmapped shaders pick up wrong UV channels.
Animation optionsControls how animations are imported:
No AnimationNo animation or skinning is imported.
Animation in rootAnimations are stored in the scene's transform root objects. Use this when animating anything that has a hierarchy.
Animation in original rootsAnimations are stored in root objects of your animation package (these might be different from root objects in Unity).
Animation stored in nodesAnimations are stored together with the objects they animate. Use this when you have a complex animation setup and want full scripting control.
Bake IK & simulationWhen using IK or simulation in your animation package, enable this. Unity will convert to FK on import.
Keyframe reductionPerform keyframe reduction on imported animations. You should always use this, as it takes less memory and is faster.
Split animation into multiple clipsIf you have multiple animations in a single file, here you can split it into multiple clips.

Material Generation

Materials are found based on the following rules:

If Unity can't find the Material, it tries to create one from the texture:

Colliders

Unity features two primary types of colliders: Mesh Colliders and Primitive Colliders. Mesh colliders are imported together with your geometry and are used for background objects. When you enable Generate Colliders in the Import Settings, a Mesh collider is automatically added when the mesh is added to the Scene. It has become solid as far as the physics system is concerned.

If you are moving the object around (a car for example), you can not use Mesh colliders. Instead, you will have to use Primitive colliders. In this case you should disable the Generate Colliders setting.

Animations

Animations are automatically imported from the scene. For more details about animation import options see Character Animation chapter.

Normal mapping and characters

If you have a character with a normal map that was generated from a high-polygon version of the model, you should import the game-quality version with a Smoothing angle of 180 degrees. This will prevent odd-looking seams in lighting due to tangent splitting. If the seams are still present with these settings, enable Split tangents across UV seams.

If you are converting a greyscale image into a bumpmap, you don't need to worry about this.

Hints

See Also