USD Thumbnail Generator

Purpose

Given a USD file, take a picture and assign it as it's thumbnail.

Usage

Single File Generation: python generate_thumbnail.py --usd-file <usd_file> Generation for Entire Directory: python generate_thumbnail.py --directory <directory> Generation for Entire Directory and Recursive Child Folders: python generate_thumbnail.py --directory <directory> --recursive

optional arguments:

• -h, --help : Show help
• --usd-file : The USD file you want to add a thumbnail to. If USDZ is input, a new USD file will be created to wrap the existing one called <subject_usd_file>_Thumbnail.usd
• --create-usdz-result : Returns the resulting files as a new USDZ file called <subject_usd_file>_Thumbnail.usdz
• --output-extension : The file extension of the output image you want (exr, png..). If using exr, make sure your USD install includes OpenEXR (exr is natively included in USD as of version 23.11)
• --verbose : Prints out the steps as they happen
• --dome-light : The path to the dome light HDR image to use,
• --width : The width of the image in pixels to generate. Default is 2048.
• --height : The height of the image in pixels to generate. Default is 2048. If height is not specified, the image is square.
• --apply-thumbnail : Saves the image as the thumbnail for the given USD file.
• --render-purposes : A comma separated list of render purposes to include in the thumbnail. Valid values are: default, render, proxy, guide.
• --directory : A directory to generate thumbnails for all .usd, .usda, .usdc, and .usdz files. When a directory is supplied, usd-file is ignored.
• --recursive : Will recursively search all directories underneath a given directory, requires a directory to be set.
• --camera : The path to the camera prim to use for the thumbnail image

Note: You must have usd installed and available in your path. Install Steps Here

How it works

Given a USD file to use as the subject of the thumbnail do the following

1. Generate a camera such that the subject is in view
2. Sublayer the subject in the camera
3. Run usdrecord to take a snapshot and store it in /thumbnails/<input>.png
   • macOS
     • usdrecord --camera ZCamera --imageWidth 2048 --renderer Metal camera.usda <input>.png
   • windows
     • usdrecord --camera ZCamera --imageWidth 2048 --renderer GL camera.usda <input>.png
     • note: this will run with shell=True for the subprocess call
   • linux
     • usdrecord --camera ZCamera --imageWidth 2048 --renderer Metal camera.usda <input>.png
   • ZCamera & camera.usda are generated in step 2
4. If the file is not a USDZ file, assign that image as the usd's thumbnail image
5. If the file is a USDZ file, create a new <subject_usd_file>_Thumbnail.usda, assign the image as the thumbnail, and sublayer <subject_usd_file>.usdz
6. If --create-usdz-result is passed in, combine all of the files into a USDZ, in the case of a USD file it would be the input file and the image. In the case of a USDZ file it would be the new USDA, the image, and the input USDZ

Thumbnail Usage

Thumbnails are being used in these apps:

• Needle Tools - Asset Explorer
  • In the Information and Downloads section of any asset, the USDZ image is using Thumbnails