Jan 30, 2017
Motion Capture Basics
Imagine convert this into 3D world. Center of the capturing area is the origin. Axes shown in the picture. 15 cameras tracking the markers to get tracking information.
The reference cameras are used to see if the mapping of the rig is always right. The reference cameras includes software that can map the ref camera into the 3D space and you can get a clearer view of that.
Before using the system, the cameras should be calibrated.
This is the markers. It has a variety of sizes and can cost about $8. The cameras emits rays and captures the reflected frequencies to identify the markers. There’s something it can not capture: hair.
After putting on the markers, the markers will be mapped in the software, but not necessary to the rig. Information of motion at each point are stored and then processed. You can map the points to rigs, skins, and you can use multiple points to calculate one joint. It is also said that you can get forces.
There are some movements that involves a lot of occlusions. E.g. swimming. They tried to hang the actor to get the motion.