Understanding 3D Camera Tracking: Part 3

Understanding 3D Camera Tracking: Part 3


Screencast



1. Project Setting

Step 1

Open After Effects.

Open After Effects
Open After Effects

Step 2

Go to Composition > New Composition to make a new composition. 

Set the Width and Height values to 1280 and 720
respectively. Set the Frame Rate to 25 and Duration to 12
seconds. Click on OK.

Composition New Composition
Composition > New Composition

Step 3

I have provided the live action footage, which can be found
in the attachment of the tutorial. Go to File > Import > File to
import the image sequence. Alternatively, you can press Ctrl-I keys.
With the first image of the image sequence selected, turn on JPEG Sequence
option. Click on Open.

File Import File
File > Import > File 

Step 4

With the image sequence selected, drag and drop it inside
the composition. You can see the footage in the comp view.

Composition
Composition

2. Camera
Tracking in After Effects

Step 1

With the image sequence layer selected, go to Animation > Track
Camera
.

Animation Track Camera
Animation > Track Camera

Step 2

The 3D camera tracker system starts analysing the footage. It analyses the
footage in two steps, hence it might take some time to complete.

Analyses the footage
Analyses the footage

Step 3

After a couple of seconds, the analyse process ends. Now you can see
several track points in the scene.

Track points
Track points

Step 4

These track points would help to generate the dummy 3D
plane/null and the camera. You need to select several points as shown in the
following image.

Select several points
Select several points

Step 5

With the indicated points selected, secondary-click the mouse and
select Create Null and Camera.

Create Null and Camera
Create Null and Camera

Step 6

You get a Null layer and 3D camera in the timeline. This Null
layer is the placeholder and sticks with the footage and follows the camera.

Null layer and 3D camera
Null layer and 3D camera

3. Creating Object in Element 3D

Step 1

I hope you all are aware with Video Co-pilot’s Element 3D. This is a robust plug-in of After Effects which lets you insert 3D models in After Effects composition. 

I would urge to go to the link to know more about it. https://www.videocopilot.net/products/element2/

To start with Element 3D, go to Layer > New > Solid.

Layer New Solid
Layer > New > Solid

Step 2

It creates a black solid layer. The Element 3D object will be applied to
this layer.

Black solid layer
Black solid layer

Step 3

Go to Effect > Video Copilot > Element.

Effect Video Copilot Element
Effect > Video Copilot > Element

Step 4

Click on Scene Setup to open the Element 3D interface.

Scene Setup
Scene Setup

Step 5

There are several default 3d objects in Element‘s directory, so you can choose any one of them. I have imported the truck wheel mesh in the view port. Click on OK.

Select an object
Select an object

Step 6

The truck wheel object has come into the scene but you need
to align it according to the camera.

Object in the scene
Object in the scene

Step 7

With the element layer selected, go to Element effect and under Group
1
roll-out menu, click on Create button. It creates Group 1 Null
layer.

Element effect
Element effect

Step 8

Copy the Position value of Track Null 1 layer and paste the
same in the Group 1 Null layer.

Copy the Position value
Copy the Position value

Step 9

You need to tweak the X Rotation value a bit to match the
orientation of the truck wheel.

X Rotation value
X Rotation value

4. Applying Lights and Shadow

Step 1

Once again go to Element 3D Scene Setup and create a plane beneath the
truck wheel in the view port. 

Element 3D Scene Setup
Element 3D Scene Setup

Step 2

Apply Matte Shadow material to the plane. Click on OK button.

Apply Matte Shadow material

Step 3

Go to Layer > New > Light.

Layer New Light
Layer > New > Light

Step 4

Create a Spot Light with Shadow option
enabled.

Create a Spot Light with Shadow option enabled
Create a Spot Light with Shadow option enabled

Step 5

With the element layer selected, go to Element effect and under Render
Settings
roll-out menu, enable Shadow and turn the Shadow Mode
to Ray-Traced. You will immediately see the shadow in the view port.

Enable Shadow
Enable Shadow

Step 6

Go to Spot Light 1 layer and lower the values of Shadow Darkness
and Shadow Diffusion parameters to soften the shadow darkness and blur
the shadow to match it with the rest of the scene.

Shadow Darkness and Shadow Diffusion parameters
Shadow Darkness and Shadow Diffusion parameters 

Step 7

Hit the Play button and you will see the truck wheel has merged with
the live action scene perfectly.

Hit the Play button
Hit the Play button

Conclusion

Tracking with Element 3D is a great fun. It is not only easy but it also minimises the dependency on 3D animation software. I will be writing some more interesting tutorials on 3D tracking in this series.



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