1. Planning the Shot
First, let’s discuss the scene. I shot this scene while standing on my balcony, it's a hand held camera shot tilting from low to high. Since there is some movement in the shot, we'll need to track the scene later. But in this case, there isn't that much rotation in the shot and the clouds will be far away, so 2D tracking will be more than sufficient rather than 3D tracking.
We will make the clouds in a circular pattern as shown in the following image. We will take 3-4 torus objects in 3ds Max and then apply the AfterBurn particle system. So let’s start!
2. Creating the Base for the 3D Clouds
Create a Torus (Create > Standard Primitives > Torus) in the viewport.
To place the clouds correctly, we need to insert the live footage into the background to use as reference.
So while in the Perspective view, press Alt-B to open the Viewport Configuration window. Check the Use Files ratio button, the Animate Background option, the Match Rendering Output button and then click on the Files button.
Since the live action footage is an image sequence. Select the first file (Sky_00000.jpg), check the Sequence option and then click Open.
It will ask for another confirmation, just press OK. Now you will see the live action footage in the viewport's background.
Choose a frame on the timeline when you see the maximum amount of sky in the live action plate. This will help us create the 3D clouds in the right place. Move the Torus up a bit from the grid so it's hanging in mid air.
Press F10 to open the Render Setup box. Here set the output dimensions to 1280/720, because the main live action footage dimensions are the same.
Click Shift-F to generate the Safe Frame bounding box.
Press Control-C to create a new Camera.
For the time being, turn off the background image sequence. With the torus selected, set the values for Radius 1 to 25.0 and Radius 2 to 5.0.
Turn on the Auto Key button. Go to the 300th frame on the timeline and animate the Rotation property of the torus from 0 to -150.0 units.
Press E to jump into Rotation transform mode and then rotate the torus to -180 degrees in the Z direction.
Turn off the Auto Key button after setting the animation keyframes. With the Torus mesh selected, go to Graph Editors > Track View - Curve Editor.
Go to the Rotation Transform and Rotation parameters for the Torus. You will see the animated keyframes interpolation is curved. This will cause an ease in - ease out type of animation.
To overcome this problem, select the keys of the animation and then click on the Set Tangents to Linear option (highlighted below). This will straighten the tangents curve and hence the ease in - ease out problem will be gone.
3. Creating the Particle Flow Setup
Now we will create the clouds using a Particle Flow system. So create a PF Source system (Create > Particles > Particle Flow Source) and open the Particle View window by pressing 6 on the keyboard.
Delete the Speed, Rotation and Shape operators from the event.
Append a Position Object operator to replace the Position Icon operator.
Go to the Birth operator and then set the Emit Start and Emit Stop to 0. Set the Amount value to 200.
Go to the Position Object operator and add the Torus into the Emitter Objects list. Turn on the Lock On Emitter and Animated Shape options.
4. Applying Afterburn to the Particle System
Press 8 to open the Environment and Effects box.
Click on the Add button and add the AfterBurn atmospheric effect.
Click on the Pick Particles hand icon and then add the PF Source into the list.
With the Torus selected, Right Click and open its Object Properties and turn off the Renderable option.
Click on the Show in Viewport button to see the AfterBurn particles in the viewport.
Now it’s time to add some lights to the scene. So go to Lights > Standard > Omni and add an Omni light into the scene. Select AB Shadow Map as the shadow type. Increase the light's intensity a bit and make it a pale orange color. Set the Super Sampling quality to 5 Star with a Quality value of 1.0.
Render the frame. As you will see, it doesn’t make any difference until we make some changes in the AfterBurn parameters.
First, add the Omni light into the AfterBurn Source Lights list.
Turn on the Shadow Cast, Shadow Receive and Self Shadow options.
Now render the scene again and you will see a significant difference in the result.
Copy the Omni light and place it above the torus cloud. Play with the position and parameters of the Omni lights to get the desired result.
Set the Ambient Color to a dark grey and the Color 1 color to light turquoise. This will decrease the darkness of the cloud.
Increase the Noise Size a bit (to 25.0) and change the Type to Smoke. This will significantly change the result.
Always play with the light settings and their placement. This can certainly add different moods to the scene.
Now make a duplicate of the Torus and Scale it up a bit.
Make another copy of the PF Source and the Event.
Select the second Torus (Torus002) as the Emitter Object in the second event.
Render the scene again and you will see that the cloud-lets are very scattered. This is because the second torus is bigger than the first, and it's sharing the same AfterBurn preset. We need to apply a different AfterBurn preset to the second torus.
First of all, remove the PF Source 002 from the first AfterBurn preset.
Now add another AfterBurn preset, and then add the second PF Source (002) and the lights. Also click on the Show in Viewport icon to see the AfterBurn particles in the viewport.
Turn on the Shadow Cast, Shadow Receive and Self Shadow options.
Increase the Sph. Radius value to 30.0.
Increase the Noise Size a bit and change the Type to Smoke. Again, this will significantly change the result.
Repeat the process from Steps 15 to 23 once again. Basically we are adding one more torus cloud.
Once done, render the scene again and you will see something like this.
All the torus objects are already animated. So we will now render the complete scene for 300 frames. But before that, go to Render Setup > Renderer and choose Catmull-Rom as the Antialiasing Filter and turn on Enable Global Super Sampler (Max 2.5 Star).
Render the scene at a 1280/720 dimension and for 300 frames.
5. Basic Compositing in After Effects
Import the live footage into After Effects. Click on Track Motion and enable the Position and Rotation options. This will add two trackers into the scene. Position these trackers at the brightest points as shown.
Click on the Analyze/Play button to check whether the trackers follow the scene or not. After a couple of seconds, you will see the trackers follow the tracking points quite well.
Create a new Null layer (Layer > New > Null Object).
Click on the Edit Target button and select Null 1 as the receiver of the tracking data.
With the help of the Pen tool, draw a mask around the sky on the live footage layer.
Bring the rendered cloud footage into the timeline, and put it beneath all the other layers.
Add some feather into the mask so that the edges of the sky merge with the clouds.
Apply a Color Balance effect and try to adjust the color. To show God rays, you can apply the CC Light Rays effect also.
Here is the final result. You can play with the settings and effect parameters to get different results. I hope you liked the tutorial. Do share your comments and views.