Welcome to Beholder, an app for quickly and easily building 3D models from photos. This tutorial takes you through the process of building your first model.

1. Gather Photos of an Object

To build a 3D model with Beholder you will need a set of photos of an object to build the model from. Taking photos for use with Photogrammetry can be tricky, so if you just want to learn to use Beholder with a 'known good' set of photos we'd recommend using the Lion dataset that can be downloaded here, and then skipping to the 'Create a New Project' section.

To learn how to take your own photos there are lots of good Photogrammetry tutorials online such as this one by Scan the World. Some general tips for getting good results are

  • Take photos of the object from all sides in one or more rings around the object.
  • Make sure that the photos are evenly spaced with good overlap between images. In general there should be at least 20 photos per loop.
  • Make sure that the object of interest takes up a good proportion of each photo.
  • Make sure that the object of interest is fully in focus in the photos.

2. Create a New Project

Once you have the set of photos that you're going to use to build your model, create a new project in the Projects tab of Beholder by clicking on the 'New Project' button, entering a name and then clicking Ok.

3. Upload Images

Upload images to the project by dragging them from your computer onto the image list section on the left.

4. Start to Align Images

Align images by clicking on the align images button. This step will work out the position and orientation that the camera was in for each of the photos that have been uploaded. Once complete you will end up with a point cloud that provides an early preview of the object you're building. Note: This stage can take quite a few minutes to complete (especially if there are lots of images) so if you prefer not to wait you can click the 'Email when job is complete' button to be notified when the image alignment has finished.

5. Adjust Pose

The photogrammetry process can sometimes build the initial point cloud in quite awkward poses. To help with this, the 3D view has a couple of buttons that you can use to adjust the translation and rotation of the 3D point cloud.

6. Start to Construct Mesh

Once you're happy with the initial point cloud built by Beholder, you can build a 3D mesh by clicking on the construct mesh button.

7. Download 3D Model

And you're done! Once the construct mesh job has finished running you can click on the download button to obtain your 3D model in one of 3 formats, depending on what you want to do with it. For example, if you want to 3D print the object you'd be best off choosing STL as the output format.

Extra: Focus Reconstruction Area with a Bounding Box

Quite often the reconstruction process will construct the geometry of extra items, around the object you're interested in, that you don't want to be included in the final mesh. To work round that, in point cloud mode you can add a bounding box to the scene that lets you specify which parts of the point cloud you want to build into a mesh.