# Input Files

The inputFiles field (dictionary) specifies which scan modalities you are sending over and how you will transfer them to the Engine API. A fixed set of input files is supported (see below). Each input file is specified in the same way, always specifying the extension and optionally specifying the download URL.

# How to transfer the data?

# A. Uploading to Relu-generated pre-signed upload URLs

If you leave the downloadUrl field empty for any input file, the Engine will provide you with a pre-signed uploadUrl for that file. The URL is provided immediately in the JSON response when submitting the job. After uploading the file, you need to notify the Engine that the file has been made available. You can do this by sending a POST request to the provided notifyUrl. This approach is followed in the quick start example.

# B. Providing pre-signed download URLs

Alternatively, you can provide a downloadUrl for the input file. This URL should point to the location where the Engine can download the file from and should be pre-signed (for a limited time). This approach is easy to set up if you already have the files stored in a cloud storage service like Amazon S3 or Azure Blob Storage. If all input files are passed this way, the Engine can start processing the job immediately after submission.

We recommend this approach, as it avoids wasting resources and time on uploading the files.

# Supported Input Files

# CBCT cbct

A Cone-Beam CT-scan can be passed along in various formats. The following extensions are supported:

Extension	Description
`.dcm`	A single DICOM file with all slices inside.
`.zip`	A ZIP archive containing multiple individual DICOM slice files (.dcm) inside.
`.nii`	A single NIfTI file.
`.nrrd`	A single NRRD file.
`.vti`	A single VTI file.

Additionally, all formats can be compressed with GZIP, indicated by adding .gz to the extension. Refer to the API spec for an overview of the supported combinations.

# IOS ios_upper ios_lower

Intra-oral scans or digital impressions for the upper and lower jaw, in the form of a mesh file. The following extensions are supported:

Extension	Description
`.stl`	An STL mesh file.
`.ply`	A PLY mesh file, supporting texture information.
`.obj`	An OBJ mesh file.
`.zip`	A ZIP archive containing a OBJ mesh file (.obj), with optional texture files (.mtl, .jpg, .png) inside.
`.drc`	A Draco-compressed mesh file.

# Facial facial

Facial scans, in the form of a mesh file. The following extensions are supported:

Extension	Description
`.stl`	An STL mesh file.
`.ply`	A PLY mesh file, supporting texture information.
`.obj`	An OBJ mesh file.
`.zip`	A ZIP archive containing a OBJ mesh file (.obj), with optional texture files (.mtl, .jpg, .png) inside.
`.drc`	A Draco-compressed mesh file.