MeshIO

This package supports loading 3D model file formats: obj, stl, ply, off, msh and 2DM. More 3D model formats will be supported in the future.

Installation

Enter package mode in the Julia REPL and run the following command:

pkg> add FileIO MeshIO

Usage

Loading works over the FileIO interface. This means loading a mesh is as simple as this:

using FileIO
mesh = load("path/to/mesh.obj")

The result will usually be a GeometryBasics Mesh. The exception are obj files with non-vertex data such as material data or "group" tags, which return a MetaMesh.

Displaying a mesh can be achieved with Makie.

Functions for mesh manipulation can be found in JuliaGeometry

Additional Information

Usage

The GeometryBasics Mesh supports vertex attributes with different lengths which get addressed by different faces (as of 0.5). As such MeshIO makes no effort to convert vertex attributes to a common length, indexed by one set of faces. If you need a single set of faces, e.g. for rendering, you can use new_mesh = GeometryBasics.expand_faceviews(mesh) to generate a fitting mesh.

The GeometryBasics Mesh allows for different element types for coordinates, normals, faces, etc. These can set when loading a mesh using keyword arguments:

load(filename; pointtype = Point3f, uvtype = Vec2f, facetype = GLTriangleFace, normaltype = Vec3f)

Note that not every file format supports normals and uvs (texture coordinates) and thus some loaders don't accept uvtype and/or normaltype.

The facetypes from GeometryBasics support 0 and 1-based indexing using OffsetIntegers. For example GLTriangleFace is an alias for NgonFace{3, OffsetInteger{-1, UInt32}}, i.e. a face containing 3 indices offset from 1-based indexing by -1. The raw data in a GLTriangleFace is 0-based so that it can be uploaded directly in a Graphics API. In Julia code it gets converted back to a 1-based Int, so that it can be used as is.

Extending MeshIO

To implement a new file format you need to add the appropriate load() and save() methods. You also need to register the file format with FileIO For saving it may be useful to know that you can convert vertex data to specific types using the decompose interface.