Import meshes

Modeler allows you to import meshes so you can bring in models you've created with other applications. Currently you can only import meshes while on desktop

To import a mesh use File > Import Mesh or shortcut Ctrl + Shift + M.

The Import Mesh dialog appears. Here you can select the file to import, and change import settings:

  • Unit scale: For file formats that support unit scale, here you can define the size of a single unit.
  • Up axis: Some 3D applications export files with a different axis oriented upwards. Select the Up-axis here to avoid rotating the mesh after it has been imported.

Once you have configured your import, click Import. Depending on the mesh complexity Modeler may take some time to complete the import.

Convert meshes to clay

Importing a mesh means that it exists in your scene. In order to modify the imported mesh you first need to convert it to clay.

To convert a mesh to clay:

  1. Equip the Select tool.
  2. Select the mesh.
  3. Open the action menu.
  4. Select Convert to Clay.
  5. Wait for Modeler to perform the conversion.

Converting a mesh to clay changes the underlying data structure. Meshes are defined by vertexes, edges, and faces, while clay is defined by a signed distance field (SDF). As a result, some information is lost when you convert a mesh to clay:

  • UVs: Clay does not use UVs, so converting a mesh to clay will lose any UVs that belonged to the original mesh. 
  • Color data: Clay can store color data, but currently the process of converting a mesh to clay will lose color from the mesh material such as base color textures.
  • Surface precision: Modeler attempts to retain as much quality in the mesh as possible, but SDFs are fundamentally different to vertex and edge data. It is impossible to convert from a mesh to clay without losing some precision, especially in very detailed models.


Non-manifold geometry

Sometimes when you convert a mesh to clay, errors may appear in the resulting clay. This is often due to non-manifold geometry.

Converting a mesh to clay takes the vertex, edge, and face data that makes up the mesh and converts it to Modeler's SDF clay format. Non-manifold geometry means that there is a physical impossibility in the vertex, edge, or face data.

For example, the image below shows a non-manifold sphere in Blender. Four of the sphere's faces have their normals flipped relative to neighboring faces.

On import into Modeler, the sphere appears to have a hole in it, however this is just because Modeler culls backfaces (Modeler doesn't render faces that don't face the camera). The faces are still there, they are facing the wrong direction.

When we convert this mesh to Clay, Modeler attempts to fix this issue, but it results in inaccurate clay.

With the smooth tool, it is possible to reduce the visibility of this particular issue. In some cases, it may not be possible to easily fix these conversion errors within Modeler.

There are many other ways for non-manifold geometry to occur in a mesh:

  • An edge that belongs to more than two faces.
  • Holes in geometry or non-watertight models.
  • Volumes that have no thickness or are flat on an axis.

Most 3D modelling applications have tools that will either highlight non-manifold geometry or automatically clean it for you. Due to how clay works in Modeler, Modeler is not able to create non-manifold geometry, and does not include tools to fix non-manifold geometry in imported meshes.