12
$\begingroup$

I am using Ubuntu 15.04 and Blender 2.72b.

I've got a video clip where I want to display some annotation-like text next to some potatoes on a white table. The potatoes move a little in the video so I would need to adjust the text a bit every few frames.

(I am a total beginner, I have not used Blender's clip editor before.)

How would I attach text to a tracked point (to the potato) and manually adjust the text's location when required?

$\endgroup$
11
$\begingroup$

Let's say you've successfully tracked an object in your scene:

enter image description here

Go to the Solve Tab and in the Geometry section and click on Link Empty To Track.

enter image description here

That will create an Empty that, if seen from the camera, moves within the frame like the tracked object.

enter image description here

At this point you might want to add your image as background for reference and make it visible for the camera axis.

Add a text object in the 3d View (ShiftA > Text ) and select the Align to View option:

enter image description here

Edit your text, set the orientation to view and place it where you need it.

enter image description here

Select your text object, then select the Empty by holding Shift and simply parent it to the Empty
(CtrlP).

The text will now move like the tracked object.

enter image description here

To render both images create a node tree like this:

enter image description here

If the text element is an image and not a 3D object

You can overlay the background video with the foreground element using the compositor:

enter image description here

The text (with a transparent background) is placed and scaled with a transform node.

The result of that is then passed to a translate node that uses the information from the tracker (select the video used and the object, usually "camera" and the tracker you want to use to control the movement)

enter image description here

Then use an Alpha over to overlay the image on top of the video background.

Tracked image in the Movie Clip editor:

enter image description here

Result:

enter image description here

$\endgroup$
  • 1
    $\begingroup$ Was a gif really necessary to show how to parent something? Or was this comment just a reason to post yet another link to my answer? :) $\endgroup$ – David Sep 15 '15 at 2:32
  • $\begingroup$ @David I'll link to your answer (even if you just have static images) $\endgroup$ – cegaton Sep 15 '15 at 2:54
  • $\begingroup$ How do you set a video as a reference background? I tried following a tutorial on youtube but nothing appeared in the 3D view. $\endgroup$ – Avamander Sep 16 '15 at 18:10
  • 2
    $\begingroup$ @Avamander blender.stackexchange.com/a/122/1853 $\endgroup$ – cegaton Sep 16 '15 at 18:20
  • $\begingroup$ @cegaton Okay, the background image appeared. I also set the camera right. It's going great :D. Altho, would I have to create five node trees for every trackable text point? $\endgroup$ – Avamander Sep 16 '15 at 19:17

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.