After Effects 8- Faking depth

[ker-plop]

I'm trying to edit a video in this program, and I need to know how to do the following:

I have a character who moves through the background, behind some columns. What can I do to actually make this character look like it's going behind the columns? Is there some technique for this, and what is it? Please keep in mind that I'm just a beginner at this. Thank you.

[guns1inger]

What footage do you have ?

If you have footage of someone walking behind columns, these isn't a lot you can do. You can try to mask the columns onto a new layer, then blur them to give a faux depth of field effect, but that is about it.

If you have footage of someone walking across the screen then you can create a new layer with columns, ad some blur and even a slight sideways movement to fake a parallax effect.

You need to provide far more detail and even a short sample of the footage if you want a more detailed answer.

[ker-plop]

What footage do you have ?

If you have footage of someone walking behind columns, these isn't a lot you can do. You can try to mask the columns onto a new layer, then blur them to give a faux depth of field effect, but that is about it.

If you have footage of someone walking across the screen then you can create a new layer with columns, ad some blur and even a slight sideways movement to fake a parallax effect.

You need to provide far more detail and even a short sample of the footage if you want a more detailed answer.

Well, unfortunately, I can't provide a sample because I promised the person I'm doing it for that I wouldn't share it until it's finished... but I can provide an example. Look at :32 in the following movie:

http://youtube.com/watch?v=PyWe1T86nq0

See how they got Luigi to pop up like that, even though the background is solid? With that in mind, I want to make that character (which I'm animating myself) walk behind the columns without making it look cheesy.
Is there a mask or something that I can put at the location of the column that will hide the character when it walks past, but not affect the background footage? I think that's what happened in this video.[/i]

[Brainiac]

I am no AE guru, but this is not difficult to do. The following is assuming you have a static background.

Begin by masking out the column(s) from the background by using the pen tool. Do this for each column that you want the subject to walk behind. You will have to duplicate the layer and apply a mask for each column. You will also need to have the original background as the bottom layer. Make sure that the moving character is positioned BEHIND the columns, but on TOP of the background. Position and size the character as needed. That's it!

Here is a link to a quick sample that I did in under 10 minutes:

http://www.digitalmemoriestn.com/downloads/mousewalk.wmv

Brainiac

[guns1inger]

When you talked about depth of field, I assumed that you were talking about altering the depth levels of an existing clip in motion. If Brainiac's example if more like what you are after, then simple masks are all that you need.