By Eric Paré / Xangle – https://xangleCs.com

Last revision: September 26, 2023

  1. Studio preparation
    1. A white room (white painted walls / floors) is your best option in order to be able to bounce the light and have an evenly lit subject with your strobes
  2. Hardware installation
    1. Structure Follow the instructions provided for the purchased model
    2. Electronic components
      1. Connect the cameras to the Raspberry Pis using the USB cable (data, 4 cameras per Raspberry Pi)
      2. Connect the camera power to the power adapter (Usb charger hub, Esper, or genuine Canon power adapters)
      3. Connect the Raspberry Pis to a USB charger hub using a USB-C cable (power)
      4. Connect the Raspberry Pis to the 8-ports switches using ethernet cables (data)
      5. Connect the 8-port switches to the master switch using ethernet cables
      6. Connect the master switch to the main computer using an ethernet cable
    3. Cameras
      1. Follow the Xangle setup instructions per camera brand for either Canon, Sony, Android or Pi cameras.
      2. Distribute your cameras on your structure according to your specific projects. In some cases, you’ll need a higher density on the face (less cameras on the back). In other cases, you’ll need to be able to cover a T-pose, meaning cameras pointing at the hands/arms of your subject (above and below). For a more generic installation, zoom out the lenses in order to be able to cover the full area within your structure. The more you zoom in, the better the details you will get, but the harder it will be to cover everything you need.
      3. Place a mannequin with texture in the center of the structure. Make sure you have enough light (constant, even) Using a mannequin is optional, but it is going to help you to automatically focus all lenses and properly see the framing for each camera
      4. Focus all lenses using the auto-focus button (this can also be done all at once via Xangle once everything is configured). You can keep the focus on “auto” as we disable it from Xangle.
      5. Framing (head-scan): zoom all lenses at 55mm and point straight for maximum coverage.
      6. Framing (full-body): zoom all lenses to about 35mm and point the cameras in order to cover the full body with an approximate 25% overlap. All cameras are vertical except #1. The first camera is normally used as the thumbnail for the Xangle gallery, so keeping this one zoomed-out allows for a clean reference sheet for your client (all poses within a single page)
      7. Try to vertically zigzag your cameras on your structure (avoid having two cameras side by side
  3. Software installation
    1. **Download XangleCs from https://xangleapps.net/downloadsMake sure you keep your Xangle version up to date by visiting this page. You’ll find the change log on https://xanglecs.com/changelog**
    2. Run the installation file
    3. Launch XangleCs.exe from the setup folderAt the first launch, a folder is going to be created in c:\users\your-user-name\xangleCs. This is where you’re going to have all of your configuration files and images captured through the software.
    4. Log in using your credentials provided at purchase time
    5. XangleCS can be used for many different multi-cameras scenarios. At the first launch, select “photogrammetry” from the proposed UI presets. You can change this at any time from the settings. This changes the menus at the top, and the modules displayed on the dashboard. But it also makes sure that the processes are optimized for photogrammetry (no mp4 generation, no calibration…)
    6. Make sure you see all of your cameras. If some are missing, it is more likely to be due to the Raspberry Pis not being seen in the network. Refer to the troubleshooting guide for more details
  4. Camera ordering
    1. Turn off all cameras
    2. Once the camera count is at zero, go to the camera panel (click on the camera count)
    3. Run the ordering process
    4. Turn the cameras one by one in the right order (camera #1 is the first one your turn on, etc)
    5. Make sure to wait the audio signal (or the increase of the camera count) before turning on the next one
    6. Confirm the ordering

Notes:

Camera #1 is usually the most front-facing one. This gets you a clean library for easy reference. In the case of a full body, zoom out #1 to 18mm (and don’t use this one for the 3d object). By doing so, you’re losing one camera, but then you get a reference shot of the full pose

  1. Light configuration

    1. Constant light (ambiance) See the full process demo on https://www.youtube.com/watch?v=KrsvGJQTLp0. These lights are not used for the capture, but only for the user experience
      1. Turn off the power on the whole structure
      2. Install the XangleBoards on the Raspberry Pis
      3. Install your LED strips on your structure
      4. Turn on the power
      5. Navigate to http://localhost:8089/lights
      6. Create presets for “100% white” and “countdown colors”
      7. At the bottom of the page, set the preset to use for the countdown (“countdown colors”) and trigger time (off)
      8. From the dashboard, edit the trigger mode to add a delay of 2000ms (2 seconds)
    2. Strobe (flash to freeze the subject)

      1. Install your flash trigger (only one) on the hotshoe of your last camera. This camera is going to be considered a “sacrifice” one and its image is not going to be used. Its purpose is only to send a trigger signal exactly halfway during the exposure time. It’s important to use the same camera model as the timing can be slightly different across different models.

      2. Install your lights and pair them to your flash trigger. Here are three different methods of light configuration that can be used. In all cases, the settings are the same on all of your flashes.

        1. Strobes, bouncing (preferred method): place the lights just outside of the structure and point outwards. In a square room, point four lights at the four corners to maximize the light bounce.
        2. Strobes, through white curtains: install white curtains (shower curtains work perfectly) behind your cameras. Install your lights behind the curtains and point at the center of the structure. You’ll usually need 6 to 10 flash units to get an even light. This method works well but may give you a harder access to your cameras
        3. Speedlights + diffusers: install your speedlights directly on the structure, and add a diffuser on each of them (folded paper, or any more fancy solution). Point directly at your subject. This is the best method if you’re in a tiny space with space around your structure

      3. In Xangle, set the trigger mode to “Freeze”, and activate the compensation (halfway during the exposure). Use a shutter speed of 1/60s, take one shot and check if you get any black frames. If your cameras are slower, you might have to go down to 1/10s

        Notes:

        The purpose of this is to freeze the subject using light (fast) instead of the shutters of the cameras (slow). By using the speed of light, it is possible to capture your model jumping or doing any kind of fast movement.

  2. Software

    1. Trigger: Fire all cameras using either the “trigger” button on the dashboard, the “b” key on the keyboard, a game pad (“b” key), or a powerpoint presenter (“black out” key).

    2. Images review: Use the Library to review your images.

      1. Use the left/right keys to cycle through the datasets
      2. Use the top/bottom keys to cycle through the frames of a dataset
      3. Use the shift + top/bottom keys to cycle through the iterations of a dataset (burst, ROM, OLAT)
      4. Use the 1,2,3,4,5 keys to rate your dataset
      5. Use the scrollwheel of your mouse to zoom in/out inside the images

    3. Frames review: There are 3 ways of reviewing the frames

      1. Dashboard

      2. /frames (web page)

      3. Library (use the “t” shortcut to toggle between the single frame and the complete list of frames)

        The size / padding of this module can be configured from the settings

    4. Single frame review: it is possible to launch windows with specific frames for fast review. To do so, open a browser with this address: http://localhost:8089/preview/22 where 22 is the frame number. You can open multiple browsers on the same computer, or on many other computers / tablets using the ip address instead of localhost (see the “devices” tab to get started)

  3. Folders & file renaming

The best use of this module is to prepare in advance the naming presets for the talent names and selected poses.

See full details on https://doc.xanglecs.com/files

  1. Complete sessions
    1. Software workflow : A usual workflow for a photogrammetry session looks like this:Xangle -> Lightroom (raw processing) -> Reality capture (3d model build) -> ZBrush (model cleaning) -> Unreal Engine (final product). Most high-end sessions are going to be in RAW quality, meaning you’ll have to edit the RAW files in Lightroom before creating the 3d object. Some 3d software can handle RAW files, but the LightRoom raw processor is the best one out there, meaning you can get more of your files by doing this extra step.
    2. Session preparation: before each session, make sure that all lenses are clean, in focus and that the cameras are well framed. Do a test shot with a real subject and perform a quick build to make sure that everything is on point. From RealityCapture, check the very low score per camera. This is going to give you an idea of the cameras that are either out of focus or pointing at non-relevant places. Check also the harddrive space and make sure you’re up to date with your Windows version
    3. Talent preparation
      1. Shaved / clean face / no make-up (head scan)
      2. No jewelry
      3. Clothes (head-scan): white t-shirt, wig cap
      4. Clothes (full-body-scan): no plain color shirt/pants
      5. No reflective, no see-through material,
      6. Wipe off sweat (have plenty of wipes around)
      7. Dots markers on the face (if required)
    4. Other requirements
      1. On most session, a color chart and scale chart datasets are required
      2. An empty shot (full body scan) might be required in some cases for background subtraction
  2. Products
    1. Gear list: https://xanglecs.com/gear
    2. Mannequin: https://amzn.to/3zLBWt1
    3. Color chart/scale chart: https://amzn.to/3p0Na6N
    4. Head rest: TBC
    5. Chair: TBC