2 Points Tracking in Blender

1. Tracking the Footage

Step 1

Open Blender.

Step 2

Click on Editor and select Movie Clip Editor.

Step 3

It opens the Movie Clip Editor. Click on Open to import the footage in the movie clip editor.

Step 4

Go to the folder with the image sequence of the footage. Select the first frame and click on the Open Clip button.

Step 5

Now you can see the footage inside the movie clip editor window. Click on Prefetch Frames button to load the image sequence in the RAM. Alternatively, you can press P key.

Step 6

Since the footage has been shot by a hand held camera so you need to perform 2 points tracking. Try to search a good contrast point to track the footage. 

Once you have searched a point, press and hold Ctrl key and click with left mouse button onto that point. A tracker appears on the footage.

Step 7

Give this track point a name as Track Point 1.

Step 8

Now, click on Track Forward button to track the footage.

Step 9

Within a couple of seconds, the footage gets tracked. You can play the footage to check the reliability of the track. In my case, the footage has been tracked without any problem.

Step 10

Now search for the second good point to track the footage. The right corner of the wall is perfect for this. Press and hold Ctrl key and click with left mouse button onto that corner. A tracker appears on the right corner point.

Step 11

Rename this track point as Track Point 2.

Step 12

click on Track Forward button to track the footage. Even this time, the footage gets tracked perfectly. The tracking has been completed successfully.

2. Camera and Armature Setup

Step 1

Create empties from both tracks. Click on Tracking tab and select Reconstruction mode.

Step 2

Click on Link Empty to Track for both tracking points.

Step 3

Go to 3D View mode. You will see two empties in the viewport.

Step 4

With the box selected, press X key. Click on Delete to delete the box.

Step 5

With the Alt key pressed, press R and G keys one after another. The camera sets on the origin and looks to the center from the top view.

Step 6

Move the camera up a bit in Z direction.

Step 7

Press 0 key to look through the camera.

Step 8

Press N for the side bar. Check on Background Images. Click on Movie Clip and select the image sequence file.

Step 9

With the first empty selected, press Shift-A key. Go to Armature > Single Bone and create a single bone on the first empty.

Step 10

Press Tab to jump into Edit mode. Pick the tip of the bone and move it to the second empty.

Step 11

Press Tab key again to leave the Edit mode. Select the right empty. Press Shift-S key for the centered cursor. With the armature selected, press Shift-S again to snap it to the right empty.

Step 12

Parent the armature to the empties. First select the armature and then select the left empty. Press Ctrl-P key and select Object (Keep transform).

Step 13

Press Ctrl-Tab key to jump into Pose mode. First select the right empty and then select the armature. Press Ctrl-Shift-C to add a constraint. 

Select Stretch To constraint. Now the armature is connected to both empties.

3. Linking 

Step 1

Go to File > Import > Image sequence as planes.

Step 2

Choose the flag.tga file which is in a sequence and click on Import Images as Planes. I have made a flag animation in image sequence which I have to composite with the live footage.

Step 3

The image plane comes with the solid grey color. 

Step 4

To see the actual texture/ animation, enable Texture in the display menu.

Step 5

To scale up the image, press S and scale the image plane.

Step 6

Attach the flag footage to the armature, so that the flag footage could follow the image. Select the flag footage and the armature respectively and then press Ctrl-P keys. Select Bone option.

Step 7

Play the footage and you will see the foreground image sequence of flag simulation going perfectly with the background footage.

The Finished Article

Conclusion

In this part of the tutorial series, I showed you how to create two-point tracking. In the next part of the tutorial, I will show how to perform four-points perspective tracking.