Step-by-Step

Object Capture

Introduction

In order that we can capture an object at the same time as capturing a subject's motion we can simply add it to the scene. Object Capture is fairly simple, this is because it is assumed that an Object is rigid and therefore provides us with a simplifying constraint

Creating a Capture Object

First, we need to add markers to an object. As the object isn't filmed, we only need the shape (density, etc are not a requirement). Place a range of markers around the shape by first applying small velcro patches (about 1cm x 1cm) to where you will add a marker. Generally we need sufficient markers to be (a) visible to a sufficient cameras and (b) to avoid the object looking like a marker set on the subjects body. Random placement is better, as in try not to place the markers symmetrically or repeat the same pattern on one side as the other.

Setting up an Object

  • Select the Capture tab at the top
  • Select the Create/Edit Objects tab on the right
  • Place your object into the capture volume, and make sure any other markered objects or subjects are outside the scene
  • Press Begin Editing and then lasso-select the object's markers under the Live 3D Workspace view
  • Under Object Creation Tools press Create Object
  • Under Object Creation Tools change the Name to something appropriate (e.g. Gun)
  • Press Save and Apply

  • Select the Active Objects tab
  • Under Available check the checkbox for the Object in order for it to be tracked and the capture data saved.

Tip: In order to place the object in the capture value, and be sure the markers are seen clearly (before "Begin Editing") it is advised that someone (without markers) lies down and holds the object up - this way it is more visible to all cameras

Now, if you go to 3D Workspace view, you will see the object has a bounding box and when we capture motion with or without other subject(s) the motion created will be recorded.