user1534: I'm trying to find someone who can make videos similar to one shown here:



At 49 seconds, the actress writes on glass to explain the concept.



Does someone know what this effect is called so I know what to ask for?
Also, if you know how to do this sort of thing, please reply.
Thanks so much,

user1531: We do this in post, and we can call this "the write on screen/glass effect", we can track her finger and write out what she is writing in the air...and more...

user1890: Upon closer examination of the sample video, she is not writing what you are seeing, her movement only approximates the motion and if you look close enough you can see it is a mime--take a good look at the "E". She is not moving correctly to get that "E". I don't know what resources you have to work with, but if you want to copy this technique you need to have 2 things:
1) an actor that can closely mimic the correct motion as if she/he is really writing.
2) a good post production video editor so you can animate the writing content on a separate video track and make a composite.
Hope this helps
ps, by the way I think the actor in your example did a marvelous job of miming the motion to trick us into believing she was actually writing the text on glass.

user6537: After seeing something similar and wondering how it was done in a video with a guy, girl video looks edited.
I tried this, and think that he actually is writing on glass, is filmed from front, with mirrored letters. After filming just simply flip video horizontal, and text will be mirrored back to normal and guy will be mirrored. Just make sure there is no other text in shot.
Clue: guy on this video is writing with his left hand, but holds pen in right handed way.

user2836: The easiest bet is to actually draw on a piece of glass and there are actually boards made for just that purpose for the classroom.  It is probable one of those is being used here and the video reversed to make it readable from the other side.  This seems likely as the video shows the guy left handed and the buttons are on the wrong side of his shirt.
The same look can kind of be achieved using write-on effects and/or animation, but you would still need some prop for the speaker to interact with so that they position their hand in roughly the right area and it still wouldn't like up exactly.
Doing this kind of shot practically is the best way to achieve it.

user442: There is a much better way to do that. That example video is a pretty poor illusion.

It can be done "for real" with with real light. But it looks
different. It has to be dark. 
You can use motion tracking to create an animation path. 
You can also use manual key frames. There are lots of tutes on the intertubes about that. Here is one: 




1534: <p>I'm trying to find someone who can make videos similar to one shown here:
<div class="youtube-embed"><div>
                <iframe width="640px" height="395px" src="https://www.youtube.com/embed/Z4Vuxk1TNoU?start=0"></iframe>
            </div></div></p>

<p>At 49 seconds, the actress writes on glass to explain the concept.</p>

<p><div class="youtube-embed"><div>
                <iframe width="640px" height="395px" src="https://www.youtube.com/embed/4Jl0CFgj3IM?start=0"></iframe>
            </div></div></p>

<p>Does someone know what this effect is called so I know what to ask for?</p>

<p>Also, if you know how to do this sort of thing, please reply.</p>

<p>Thanks so much,</p>
 1531: <p>We do this in post, and we can call this "the write on screen/glass effect", we can track her finger and write out what she is writing in the air...and more...</p>
 1890: <p>Upon closer examination of the sample video, she is not writing what you are seeing, her movement only approximates the motion and if you look close enough you can see it is a mime--take a good look at the "E". She is not moving correctly to get that "E". I don't know what resources you have to work with, but if you want to copy this technique you need to have 2 things:</p>

<p>1) an actor that can closely mimic the correct motion as if she/he is really writing.
2) a good post production video editor so you can animate the writing content on a separate video track and make a composite.</p>

<p>Hope this helps</p>

<p>ps, by the way I think the actor in your example did a marvelous job of miming the motion to trick us into believing she was actually writing the text on glass.</p>
 6537: <p>After seeing something similar and wondering how it was done in a video with a guy, girl video looks edited.
I tried this, and think that he actually is writing on glass, is filmed from front, with mirrored letters. After filming just simply flip video horizontal, and text will be mirrored back to normal and guy will be mirrored. Just make sure there is no other text in shot.</p>

<p>Clue: guy on this video is writing with his left hand, but holds pen in right handed way.</p>
 2836: <p>The easiest bet is to actually draw on a piece of glass and there are actually boards made for just that purpose for the classroom.  It is probable one of those is being used here and the video reversed to make it readable from the other side.  This seems likely as the video shows the guy left handed and the buttons are on the wrong side of his shirt.</p>

<p>The same look can kind of be achieved using write-on effects and/or animation, but you would still need some prop for the speaker to interact with so that they position their hand in roughly the right area and it still wouldn't like up exactly.</p>

<p>Doing this kind of shot practically is the best way to achieve it.</p>
 442: <p>There is a much better way to do that. That example video is a pretty poor illusion.</p>

<ol>
<li>It can be done "for real" with with real light. But it looks
different. It has to be dark. </li>
<li>You can use motion tracking to create an animation path. </li>
<li>You can also use manual key frames. There are lots of tutes on the intertubes about that. Here is one: <div class="youtube-embed"><div>
                <iframe width="640px" height="395px" src="https://www.youtube.com/embed/x-Axf9oJ4Jk?start=0"></iframe>
            </div></div></li>
</ol>
