Camera tracking with Blender3D

Recently I've been doing a lot of visual effects work and thought it would be good to share some methods I've been using. I wanted to start with using Blender3D to place 3D objects into your footage. A simple example of the final effects can be seen here



In this tutorial I will show you how to achieve this effect using Blender3D (available for free here) and pfTrack from Pixel Farms (Available for purchase here). While pfTrack is a commercial application, there are free alternatives such as Voodoo Camera Tracker, available for download from DigiLab here. Now to start the tutorial:

1. Open up pfTrack and create a new project (File>New Project)


2. Import the footage that you want to insert the 3D object into (File>Import Footage)


3. Go to Tracking>Track and Solve.

pfTrack will now analyze your footage and determine the motion of the camera. pfTrack does this by following the motion of pixels during the footage. Depending on the size of your footage, this may be a slow and painful process.

4. Once pfTrack has finished analyzing your footage, right click the "Camera Exports" list item with the 3D icon next to it (located in the far left bar) and click "New"


5. Choose the 3D software you are using from the "Format" list (we will be using Blender3D in this tutorial). Next, click "Browse" to choose the location in which your script will be saved.


6. Click "Okay" to close out the pop up. You will notice that a new item has appeared under the "Camera Exports" list item, right click this new item and choose "Export".


7. Close out of pfTrack and open up Blender3D

8. Open up the text editor in Blender3D and open the script pfTrack just exported


9. Run the python script (Text>Run Python Script). Blender3D will now key the camera's motion to replicate the camera in your footage

10. Switch Blender3D back to the 3D view. You will see all the motion points the pfTrack script added

11. Open up the background image menu (View>Background Image) and click "Use background Image"

12. Click the folder icon and choose your original footage and the click the "Auto Refresh" button


13. Switch to camera view (View>Camera). Flip through the frames using the Up and Down arrows. You will notice you footage playing on the screen and that the camera moves to match the footage

14. You can now insert any 3D objects you want. Make sure to check that the rotation, location, and scale match the footage by viewing the scene through the camera. Once you have inserted your 3D object, simply go to the render menu and click "Anim". You will now have an animation of your 3D object that matches the camera movements in your footage. You can then use a composting software like Adobe After effects to place 3D animation on top of your original footage.

I hope you enjoyed my first tutorial on this blog! Please feel free to post questions/comments.