3D Tracking with Shadow Catcher in After Effects [video tutorial]

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3D Tracking? Shadow Catcher? Seems interesting, right?

Welcome to the second blog post of our tracking motion series. We have already figured out how to create simple motion tracking in After Effects.

So let’s start talking about 3D Tracking with Shadow Catcher.

Note: Remember to watch the video tutorial, you will understand easier what Jeff does.

We will go to the last one here, this is a little bit different because we’re going to use a shadow catcher on this one. Because I know the sun is coming from the left so the shadows here are falling on the ground.

I want to simulate that there’re some shadows here so it would be weird for the text to be floating up against the vines without having some shadows fall on them.
This gets a little tricky and the last time I did, the shadows didn’t behave properly, they remained sharp. I’m not sure why they did. So we’ll see if they stay sharp this time or not.
Click on the video to make it active. We’ve already tracked it.

There’s the camera tracker. And you can barely see the little guys.

camera tracker

The targets are ok but the little spots are barely visible.

So I’ll make them more visible by increasing the size of the track point.

The reason the target’s large is I’ve already made it large.
If I take it back down 100 percent and that 100—you can barely see the target too. It’s somewhere down there.

All right, so make the track point size and the target size large by just dragging that and pressing the “Shift.”

As I drag it, it makes it drag faster, make the targets bigger, there we go.

Now I could see them. Close to the camera, they’re big. Further away they’re smaller.
I want to get something that kind of skews down the aisle here.

Click on that. Right-click. And I wanted first to create a shadow catcher camera and light.

create shadow catcher

The shadow catcher is a solid layer that has material options because it’s in 3D. And the material option regarding shadows is that it receives shadows only.

So it’s transparent but it shows shadows, that’s how shadow catchers work. So it’s just a solid layer where it’s been changed, it says receive shadows only.

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Here’s the video tutorial:

 

We’ve used this before when we wanted to simulate putting a shadow in a 2D scene.

We just:

  • created a solid layer,
  • rolled it back a little bit,
  • waited for the shadow to fall in it,
  • and then just had it be shadow only.

So it’s the same process we’ve used before. It’s just a solid layer with the option for shadows to be shadow only.
Now I’m going to click on this again. Right-click on it again, and say “Create Text.”

text light shadow catcher

So this text there, and light, and shadow catcher.

Now the weird thing about working with shadow catchers and the lights is that it’s hard sometimes to find the darn light and then adjust it to make it work the way you want it to.

And also, notice:

the text came up black.

The reason it came up black is because the light’s not shining on the text properly. It’s kind of—in some places, the text is not being illuminated by the light, weird. But that’s more of little things about working with a 3D camera tracker.

So the way you resolve that is

by moving the light right on top of the text and then start moving it away so you can see it better.

So the way I do that is

I go to “Text,” and I go to “P” for position and I click on “Position.”

Notice the position is just insane. It’s 23,000 that means it’s way, way, off to the right relative to the scene. And 4,000, I mean, I could see so far away from where we expect it to be.

And then 38,000 meaning it’s so far back in the scene that if we went to the top view we wouldn’t even find it. So it’s a long way away. But the camera sees it. That’s what’s important.

All right, so I’m going to

click on “Position,” “Control + C,” to copy it.

Go to the “Light,” “Control + V,”

and it puts the light, now you can see the little reticule there. You can barely see it probably but that’s the light right there on top of the text.
We’ll zoom in a bit by pressing

the “Period” key, and press one more time. “Space bar.”

And that is the light right there.

text
All right, now we can play with the position a little bit.

So we go to light

press “P” for position.

I want to move it to the left, slide it to the left. Hopefully, we’ll begin to see the text shining a little bit.
And I want to lift it up a little bit like so. So lifting the light up. A little bit at a time.

All right, actually making the number smaller, that lifts things up in the X, Y, Z world here. I can pull it a little bit left again. Now it’s shining on the text.

And actually, I don’t want it to shine on the text. We’ll deal with that later. I just want the text to be white.

But now where is the shadow catcher?

Well, the shadow catcher is located in the same place as the text is.

So you can’t see the shadow catcher but if I slide it this way, now you could see the shadow catcher beginning of the shot.

shadow catcher
I’ll pull back a little bit so you can see the whole “Shift + /.”

That’s why it’s important to put things all in the same place; you can begin to see them all.

And now, what is the shadow catcher? Let’s take a look at that.
So I’m going to open this up here and press

“AA” for the material options.

And here it says; “Accept shadows only.”

That’s the trick here. I’m going to make it so it just is accepting shadows on.

accepts shadows on

Now you can see the whole—that’s the solid thing right there. So you want it to be big enough to catch all the text behind it. You also want to move it such that it’s not smacked up against the text. So I’m going to try to get back a little bit left.

I need to get the shadow catcher and press “P” for positioning because I keep on grabbing the entire scene instead of it. Now you can see the shadow catcher moving there.

You see that it gets bigger the farther away you go because it’s showing the shadow off from the distance.

You need to scale it up a bit

so I press “S” for scale

And we’ll scale it up so you can see it.

Remember the After Effects Shortcuts for changing layer properties?

I’ve seen the scale in this direction, so you want to break it. Break the link here.

break the link

Pull this thing toward you a bit. I want to make the X value higher. And I can slide her into the space using the anchor point again.

So press “A” for anchor.

It’s not critical but you can see that you want to slide in space like this. Make sure it’s kind of centered-up over the text.

So you can see how it works now.

And I’m going to take the light and lift the light up so that the text shadow is not directly behind.

So you go to the light, I’m going to lift that up.

So that means I take the Y value and take it down.

But there’s the light going up, and there’s the shadow going down.
All right, and I’m going to go to the text and go to its material values, and turn off the ability for it to receive light. Because I don’t want it to do that, this one’s going to be white.

So “AA” for the effects. And so, “Accepts lights,”

I’m going to turn that off. I just want it to be white.
All right, and now I want the shadow to be diffused which is not here. It’s a sharp. And this is where things got weird last time.

I’m going to double-click on the lights.

light settings

And you notice that the shadow infusion is zero, and the shadow darkness is 100 percent.
Let’s see if it works this time.

I’m gonna go to shadow diffusion and make it higher (167px). I could also decrease intensity, il all goes well until I click OK.

So we’re gonna leave it like this for now.
I’m going to go down to the shadow catcher. I want it to be “shadow only”, right?

So I go back down here and

press “AA” for the material options.

I’m going to go to “Accept Shadow to be only,” so out of the shadows there. And I think that it could be a little closer to the text.

so press “P,” for position again.

And I’m going to take the Z value and bring it a little bit closer to the text. Z value, pull it towards it like that.
And I could make the text a little bit larger.

I could change the text, I could rotate it a little bit.

It’s not quite what I want but I just want to show you how this works basically that you can add these things to the scene.
Let me just do a little bit work on the text. I’ll go click on Text. I’ll type, “Pinot Noir”.

And we’ll press “R.”

And you can see it’s kind of lining up in there and it’s going to fall off the edge of the shadow catcher now.

I’ll rotate it a little bit on the Y axis so it kind of goes up against the grapes a little bit, the vineyard a little bit better.

  • Press “A” for anchor point
  • Slide it along the anchor point a little bit like so.
  • Go down a little bit.

And the shadow catcher is now off the edge, you really can’t tell.

So I’ll go back to the shadow catcher, “AA” for it.

Turn the “Accept shadows” back on again so you can see it again. You can see how big it is. And it’s kind of rotated into the words.

See that? It’s not quite aligned with the text in terms of rotation.

So press “R” for rotation.

I want it to rotate on the Y axis a little bit so it can behave properly like that.

Something like that, that’s more like it.

rotation

And we can adjust the position of the light a little bit so that it doesn’t run off the right-hand side here. However we want to deal with it but that’s how the basic process works.

We go back to scale and we’ll increase the scale of the letters so you can get the shadow catcher to go off the scene. Okay, and back to “AA” again to turn the thing to do be just “shadows only”.

And now you can see how that works.

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Remus Hosu

Remus Hosu

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