Scene Settings Meshes Tab

In the Meshes tab, you can create mesh groups to be processed as mesh product assets. By default, all meshes that aren’t designated as a level of detail (meshes named with a _lod<n> postfix) or as a PhysX mesh (meshes named with a _phys postfix) are processed in a single mesh group. You can create any number of mesh groups containing specific meshes from the source asset. Each mesh group produces its own product assets. The runtime product assets appear in Asset Browser as children of the source asset.

The Meshes tab is available if the source asset contains at least one mesh.

Meshes tab properties

Property	Description
Add another mesh	Add a mesh group to process. Each mesh group can contain one or more meshes from the source asset file. Each mesh group produces a single .azmodel and as many .azlod and .azbuffer product assets as required.
Name mesh	The name of the mesh group. All product assets for this mesh group use this name as a prefix. This name is displayed on product assets for this mesh group in Asset Browser.
Select meshes	Choose the Selection list button to display a list of meshes found in the source asset. Select meshes from the list to include them in the mesh group. If the source asset 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 source assets. Choose the Add Modifier button to display a list of available modifiers. Some modifiers might not be available unless the gem that provides the modifier is enabled in your project.

Cloth

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

Note:

Each mesh in the mesh group to be simulated 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 is treated as disabled. A cloth mesh needs to be processed independently and cannot be merged with other meshes. For more information, refer to Simulate cloth with NVIDIA Cloth.

For information on the Inverse Masses, Motion Constraints, and Backstop properties below, refer to Per vertex properties for cloth.

Comment

Add a comment to the file for the mesh group. You can add a comment about changes made to the source asset 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.

Coordinate system change

The Coordinate system change modifier is used to reorient a 3D scene source to Open 3D Engine’s (O3DE) coordinate system. Most digital content creation (DCC) applications use a right-handed coordinate system with Y as the up axis. O3DE’s coordinate system is left-handed with Z as the up axis.

The Coordinate system change modifier has the following two modes:

Basic coordinate system change

Advanced coordinate system change

Change the Translation (position), Rotation (orientation), and Scale of a mesh relative to how it was authored.

Level of Detail (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 progressively simpler LOD.

With Scene Settings, you can specify up to five LODs (not including the base mesh) that are numbered [0] to [4], with [0] being the highest level of detail. LODs are not required but are recommended because they help get the best performance and visual fidelity across a range of platforms with different hardware capabilities.

• Choose the Add button to add an LOD.

• Choose the Delete button to remove an LOD.

• Choose the Selection list button to specify the meshes to include in the LOD.

You can also define your optimized mesh names using a soft naming convention, which defines naming rules for automatically adding a Level of Detail modifier and assigning the meshes to the appropriate LOD slots. LODs are ordered from 0 (the highest level of detail), followed by progressively lower levels of detail to meet the O3DE application needs.

For example, you may add _lod0, _lod1, _lod2, _lod3, _lod4, and _lod5 as suffixes to your mesh names. _lod0 is the base mesh with the highest resolution geometry, textures, and materials and is assigned to the base mesh group. _lod1 is assigned to LOD slot [0], _lod2 is assigned to LOD slot [1], and so on.

The scene settings pipeline relies on the soft naming convention settings defined in SoftNameSettings.setreg for rules to identify the LOD meshes. The rules allow for various formats of name suffixes, including _LOD0, _LOD_0, Lod0, _Lod_0, _lod0, and _lod_0 (upper, lower, CamelCase, etc.).

To override those default settings, please use the project user registry (<project-root>/Registry) or the global machine registry (typically found in the users home directory under .o3de/Registry/) instead of modifying SoftNameSettings.setreg directly. Check Settings Registry for more information on providing settings and configurations for O3DE applications and tools. For example, you can add a new settings registry file like below under <project-root>/Registry to exclude children of the LOD0 nodes:

{
    "O3DE": {
        "AssetProcessor": {
            "SceneBuilder": {
                "NodeSoftNameSettings": [
                    {
                        "pattern": {
                            "pattern": "^.*_[Ll][Oo][Dd]_?1(_optimized)?$",
                            "matcher": 2
                        },
                        "virtualType": "LODMesh1",
                        "includeChildren": false
                    },
                    ...
                },
                "FileSoftNameSettings": [
                    ...
                ]
            }
        }
    }
}

Note:

You may add any number of soft naming convention settings by overriding the default settings registry, but each O3DE system has its own limit on the maximum LODs: Atom renderer supports up to 10 LODs while each actor can have up to six LODs.

Material

The Material modifier helps automatically manage the contents of the .material 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 or emissive color.

Mesh (Advanced)

The Mesh (Advanced) modifier adds advanced mesh processing features such as mesh merging and vertex color stream selection.

Skin

The Skin Modifier sets limits for processing skin weights for meshes that are bound to a skeleton.

Tangents

The tangents modifier either imports tangents and bitangents from the source asset, or generates them during asset processing. Tangents and bitangents are vertex attributes that are used in various shading calculations. Tangents and bitangents are particularly important for skinned meshes and for normal and relief maps.

UVs

The UVs modifier either imports a UV Map from the source asset, or generates them during asset processing. UVs are vertex attributes that control where texture maps are sampled from for a given area in a mesh. UVs are required in order for tangent and bitangent generation to function correctly.

Note that most DCC tools generate far better UV sets than can be generated with this setting, but it may be useful in situations where the source data has no UVs defined in it and you would like to get something to render without having to open the data in a DCC tool to modify it and supply UVs.

When no UV modifier is present, nothing is done by default to the source scene, regardless of whether or not the meshes have UVs.