In this tutorial I will show you how to track an object in your camera shot (in my case a human head) with PFTRack. It does not matter if your camera is moving or stationary, because the steps for object tracking stay the same. However, with a moving camera you will have to track your camera movement on top of tracking your geometry if you need to place other objects in the scene.
You can download the PLE for PFTRack here.
“The only limitations in PFTrack 4.1 PLE are the ability to export camera and image data. Projects created in PFTrack 4.1 cannot be opened in the retail version, limiting PFTrack 4.1 PLE to non-commercial use.” (infos here)
1. Import your footage.
2. Tell the Camera wether it is static or a free move or just rotation (Camera –> Camera Paramters). If you have a moving camera and if you need to place other objects in your scene besides the head, you should track the scene first (and solve the camera) before bringing in your tracking geometry. After your scene is tracked go to Tracking –> Groups and make a new one. Highlight the new group in the left window and complete the following steps:
3. Import a tracking geometry – the object should match as good as possible with the actor’s face.
You do not have to model the actor’s face yourself, just use the FaceGen Modeller instead (it is available for $299 USD and if you are an student you can buy 4 licenses for the same prize). Within the FaceGen Modeller it is also possible to let the program model for you by using photographs:
If you do not use the free version of FaceGen you can now export the face as an obj model and bring it into PF Track (see above), where you should line up the head with the actor (therefore use Shift+Mouse buttons).
4. Paint weights where the new geometry is too big or where the actor moves his eyes or lips. If you highlight the model in the option box on the left you will get this shelf:
Where there now is written “wireframe” chose “weights”, click on -W and paint those areas red where the actor moves his/her eyes or mouth and where the model is too big/small (chin, eares,…). It is important that you align and paint the face on the frame from which you want to track forwards or backwards.
5. Go to the frame on which you painted the weights and aligned the face, and press the >> button to track forward or the << button to track backwards. You will find those on the same shelf where you chose to paint the weights.
And voilá, your geometry moves along nicely with your face.