FBX Settings Meshes tab - Lumberyard User Guide

FBX Settings Meshes tab

This feature is in preview release and is subject to change.
Open 3D Engine (O3DE), the successor to Lumberyard, is now available in Developer Preview. Download O3DE or visit the AWS Game Tech blog to learn more.

All meshes in the .fbx file are processed to a single runtime asset (.cgf) by default. In the Meshes tab, you can create mesh groups containing specific meshes from the .fbx file. Each Mesh group produces its own .cgf file. The processed runtime assets appear in Asset Browser as children of the .fbx file.

Meshes tab properties


                The FBX Settings Meshes tab.
Add another mesh

Add a mesh group to process. Each mesh group can contain one or more meshes from the .fbx file. Each mesh group produces a .cgf file.

Name mesh

Enter a name for the mesh group. This is the name of the .cgf file containing the processed meshes. The .cgf file appears in Asset Browser as a child of the .fbx file.

Select meshes

Specify the meshes to process from the .fbx file for this mesh group. Choose the Hierarchy icon to see a list of meshes found in the .fbx file. Select meshes from the list to include them in the mesh group and process as visible render meshes. If the .fbx contains meshes that are intended to be used as PhysX collider assets, you should exclude them from the Mesh group by deselecting them in this list.

Add Modifier

Modifiers add specialized options for processing assets. Choose the Add Modifier button to see a list of available modifiers:

  • Cloth

  • Comment

  • CryPhysics Proxy

  • Level of Detail

  • Material

  • Mesh (Advanced)

  • Origin

  • Touch Bending

Note

Some modifiers are not available unless the gem that provides the modifier is enabled in your project.

Cloth modifier


                The FBX Settings Meshes tab Cloth modifier.

Add NVIDIA Cloth data to a selected mesh to simulate cloth physics.

Note

Each mesh in the Mesh group to simulate as cloth requires its own Cloth modifier.

When a Cloth modifier is added to a mesh group, the Merge Meshes property in the Mesh (Advanced) modifier will be ignored and treated as disabled. A cloth mesh needs to be processed independently and cannot be merged with other meshes.

For more information, see Simulate cloth with NVIDIA Cloth.

Select Cloth Mesh

Select the mesh to have cloth data applied and simulate as a cloth object.

Note

For information on the Inverse Masses, Motion Conrstraints, and Backstop properties below, see Per vertex properties for cloth.

Inverse Masses

Select a vertex color stream to apply per vertex inverse mass data for cloth simulation. If no vertex color stream is selected, an inverse mass value of 1.0 is assigned to all vertices in the cloth mesh.

Inverse Masses Channel

Select the channel in the vertex color stream that contains inverse mass data.

Motion Constraints

Select a vertex color stream to apply per vertex motion constraints data for cloth simulation. If no vertex color stream is selected, a motion constraint value of 1.0 is assigned to all vertices in the cloth mesh.

Motion Constraints Channel

Select the channel in the vertex color stream that contains motion constraints data.

Backstop

Select a vertex color stream to apply per vertex backstop data for cloth simulation. If no vertex color stream is selected, backstop is disabled for the cloth mesh.

Backstop Offset Channel

Select the channel in the vertex color stream that contains backstop offset data.

Backstop Radius Channel

Select the channel in the vertex color stream that contains backstop radius data.

Comment modifier


                The FBX Settings Meshes tab Comment modifier.

Add a comment to the file. You can add a comment about changes made to the .fbx file for tracking purposes or notes on export options, for example. Comments don't affect how files are processed. Multiple comment modifiers can be added to a mesh group.

Level of Detail modifier


                The FBX Settings Meshes tab Level of Detail modifier.

Add level of detail (LoD) meshes to the Mesh group.

  1. Choose the + button to add an LoD.

  2. Choose the Trash Can button to remove an LoD.

  3. Choose the Hierarchy button to specify the meshes to include in the LoD.

LoDs are optimized meshes with progressively lower polygon counts, fewer and smaller textures, and simplified materials. The farther an entity is from the camera, the less detail is required from the meshes that make up the entity. As the entity moves farther from the camera, it swaps to a lower LoD.

In addition to the base static mesh, you can specify up to five LoDs which are numbered [1] to [5], with [1] being the highest level of detail. As the entity moves further from the camera, it will transition from the base mesh to LoD 1, and progressively through the LoDs the further it moves from the camera. LoDs are not required. Creating LoDs, however, is recommended because they help get the best performance and visual fidelity across a range of platforms with different hardware capabilities.

Note

When you author the mesh in your 3D application, you can add _lod1, _lod2, _lod3, _lod4, _lod5 as suffixes to your mesh names to automatically add a Level of Detail modifier and assign the meshes to appropriate LoDs. _lod1 is mapped to [0], _lod2 is mapped to [1], and so on.

Material modifier


                The FBX Settings Meshes tab Material modifier.

The Material modifier helps automatically manage the contents of the .mtl file that corresponds to the mesh group when mesh assets are updated.

A material is a combination of shaders and properties that define the surface of a mesh. Materials contain shader and texture assignments, settings for shader properties such as smoothness, opacity, emissive color, etc., and if necessary, a physics material assignment that defines physical properties such as friction. A mesh group processed with a file named myfile.cgf has a corresponding material file named myfile.mtl.

When a mesh group is processed, Asset Processor generates a material file (.mtl) containing a list of materials and their properties for the mesh group. A mesh can have multiple materials, and a mesh group can have multiple meshes, so the .mtl file might contain several materials even if the asset seems simplistic visually.

Update materials

When enabled, updates the texture map file names in the .mtl file to match the texture map names in defined in the .fbx file.

Remove unused materials

When enabled, removes materials that are present in the .mtl file that are not defined in the .fbx file.

Mesh (Advanced) modifier


                The FBX Settings Meshes tab Mesh (Advanced) modifier.

The Mesh (Advanced) modifier adds advanced mesh processing features such as a setting for vertex precision, which can save memory, and a setting to choose a vertex color stream to include in the processed mesh.

Vertex Precision

Select the precision of the vertex data for the mesh group. 16-bit floats have a range of -65,500 to 65,500 and 3 significant decimal places. Using 16-bit precision results in a much smaller file size for processed meshes, but vertices in the resulting .cgf file might shift slightly from their positions in the .fbx file. This position shift might be noticeable on large meshes, meshes with precise detail, or meshes that are placed far from the origin. Choose 32-bit precision for larger maximum values and more significant decimal places if the vertices appear to have shifted in the runtime asset.

Important

32-bit precision vertices consume more resources and might result in a loss of performance on some platforms. Some platforms have native support for 16-bit precision which can offer improved performance. Check the capabilities of your target platform to determine which precision offers the best results.

Merge Meshes

When enabled, combines all sub-meshes in the mesh group into a single mesh for optimization.

Use Custom Normals

Enable this property to use custom normals, otherwise, Asset Processor generates averaged normals.

Normals are vertex attributes that define the surface direction of your meshes. Normals can be customized in third-party modeling tools to make a mesh appear faceted, create hard edges between surfaces, or smooth the appearance of a surface. Custom normals can be included in .fbx files.

Vertex color stream

If the mesh for this Mesh group contains a vertex color stream, it can be selected from this list to be processed.

Vertex color streams contain per vertex color data that can be referenced by materials. Vertex color streams are also often used for tagging meshes with arbitrary data such as the inverse mass value used in cloth simulation. Because of this, a mesh might have multiple vertex color streams. Be sure to select a vertex color stream intended to be referenced by materials if multiple streams exist.

Origin modifier


                The FBX Settings Meshes tab Origin modifier.

Change the position (translation), orientation (rotation), and scale of a mesh relative to how it was authored.

Relative Origin Node

Select the transform relative to which the mesh is processed. By default, the mesh origin is placed at the scene position 0, 0, 0 in the .fbx file.

Translation

Sets the position offset of the processed mesh.

Rotation

Sets the orientation offset of the processed mesh in degrees.

Scale

Sets the scale offset of the processed mesh.

Touch Bending modifier


                The FBX Settings Meshes tab Touch Bending modifier.

The Touch Bending modifier sets up mesh assets for touch bending. Touch bending is a collision effect, typically used on vegetation assets such as plants or tall grass, that causes the asset to bend away from an entity that brushes against it. You can use this modifier to create a field of wheat, for example, where the wheat parts and bends as a player character passes through.

Touch bendable assets require a rig similar to an actor. For more information on creating touch bendable assets, see Adding Touch (Collision) Bending Effects.

Select root bone

Specify the root bone of the touch bendable mesh.

Proximity Trigger Mesh(es)

Choose the Hierarchy button to select collision meshes that trigger the touch bending effect. Multiple trigger meshes can be selected, however, each additional trigger mesh decreases performance. A new PhysicsNoDraw material with a NoCollide type is created for the mesh(es).

Stiffness

Set a stiffness value between 0.0 and 1.0 for all branches to define how easily the asset bends.

Damping

Set a damping value between 0.0 and 1.0 for all branches to define how quickly the asset returns to its rest position after a collision.

Thickness

Set a thickness value for all branches to define the amount of bending. Thickness is determined as the radius of a cylinder in meters. Most often a small decimal number less than 1.0 is required. Valid values range from 0.00001 to infinity.

CryPhysics Proxy modifier


                The FBX Settings Meshes tab CryPhysics Proxy modifier.
Important

The legacy physics system will be deprecated in a future Lumberyard release. Use the PhysX system instead.

Select meshes to use as proxy physics meshes for the legacy physics system.

Physics meshes

Choose the Hierarchy icon to specify the meshes to use for physics proxies from the .fbx file. Physics proxies are meshes that encapsulate render geometry (for example, hit detection or physics collision) and are optimized with a low polygon count for better performance. Primitives such as a cube, sphere or capsule are best for optimal physics performance.

Note

If your .fbx file includes a mesh node with the suffix _phys, the mesh node automatically adds a new Physics Proxy modifier.