Hi.
My company has just bought the optitrack system to perform facial motion capture. I'm currently testing the system
but I'm having a hard time improving my current results.
More specificly, there is unfortunatly less documentation about facial mocap workfloy on the Natural point website.
I've been trying to find answer to questions like :
- What the optimal camera configuration (6 cameras in our system) for facial mocap?
I have seen setups where the 6 cameras are placed on a plane facing the actor, which seems to be wise since all
cameras see all markers at every frame (considering small head movement). Is this the recommended setup ?
- In the same context, in the calibration phase, shall we go through the whole capture volume (which is not closed if the cameras are located on a plane) with the wand, or shoud we just provide calibration points located where the face is going to be?
I'm getting very different calibration scores for these two variants. While the calibration phase is documented for body mocap (video tutorial on the website), I tend to think it must be somewhat
different for facial mocap. Can you help me with that ?
Thank you for your time.
Nicolas.
special setup and calibration for FACIAL motion capture
-
spaceapple
- Posts: 5
- Joined: Sat May 02, 2009 11:12 am
Re: special setup and calibration for FACIAL motion capture
Hello,
For facial capture with 6 cameras, I usually have 3 high and 3 low cameras. High ones are placed around head height, low ones are around chest height. Middle cameras will be looking at the face from the front, while the left and right cameras will be from around 45 degree angles. All cameras are placed about 2 feet away from the face in arc aimed toward where the face will be.
With smaller capture volume like for facial, using smaller marker for the wand could improve calibration result. You can attach 4mm semisphere marker on a stick. When waving the wand, try making vertical and horizontal circles moving toward and away from cameras. The green lines in the calibration wizard should fill most of the windows.
For facial capture with 6 cameras, I usually have 3 high and 3 low cameras. High ones are placed around head height, low ones are around chest height. Middle cameras will be looking at the face from the front, while the left and right cameras will be from around 45 degree angles. All cameras are placed about 2 feet away from the face in arc aimed toward where the face will be.
With smaller capture volume like for facial, using smaller marker for the wand could improve calibration result. You can attach 4mm semisphere marker on a stick. When waving the wand, try making vertical and horizontal circles moving toward and away from cameras. The green lines in the calibration wizard should fill most of the windows.