Thursday, September 25, 2008

Speed Particles

I learned this great expression to drive particles based
on the speed the emitting layer is moving.

See the result

mov / wmv

Monday, September 22, 2008

Particular Muzzle Flash

This is the muzzle flash I used in the previous video. Main tools used were Particular and Vector blur. I started by creating a burst of particles and distorted the layer using vector blur. After that it was just madness and mayhem. I ended up having 29 layers in the final comp.

Watch the video mov / wmv

Zip file here

The Bullet

Inspired by the short video "The Bullet" by Andrew Kramer.

Watch the video mov / wmv

Wednesday, September 17, 2008

Day to Night

I think the key is pretty close to the best one can get using DV footage.

I also wanted to try this day to night transformation in a different way. I used 3D max to make a quick model of the background, lighted the scene and rendered couple of layers which I then imported to After Effects for compositing.

Watch the clip here

Friday, September 12, 2008

Chroma Key

Watch the video mov / wmv

Here is another short clip from last spring. I had recently bought my new camera and was trying out some green felt I thought could work as a chroma backround. I only had a very narrow slice of that felt so it had to be shot quite close to the screen. To light the background evenly three 300w worklights were spread aprox. 3 meters away and 2.5 meters high. These lights were used as my keylight. On the right side I placed a 150w worklight a little too close and on the left there was a window to give some of that backlight. It made a nice impression of a bright light source, like a window, being right behind the character.
Eventhough lighted evenly, the fact that I had to shoot at close range left some felt texture showing, leaving the key a bit too noisy. I managed to remove most of it, but there are still some points where you can see the outline wiggling.

There are three plates in this shot: the character, the street and the window, which is a black solid with the text and some noise and splatter added to it.

I wanted to have a look of a shallow depth of field with the camera focusing on the background when the character looks over his shoulder. So I created a camera, made the plates 3D layers and moved them on the z axis. I set the aperture and blur level to get the result I wanted and then animated the focus distance.

Tuesday, September 2, 2008

Flying Man "How to"

Before you start following this tutorial please read it through first.

What you need is an action plate where your actor does his jumping, a freeze frame of that character and an empty background of your set with camera tilting up. When shooting the tilt, make sure you shoot it slow and smooth enough. The speed can and will be adjusted in post. You don't need to film this with a chroma screen because there is only one frame to rotoscope.
So, let's get started.

Create four comps. Action plate, Flying man, Background tilt and Empty background.
Action plate is your footage before the jump; Flying man is the freeze frame of your character;
Background tilting is footage of your empty background with the camera tilt; Empty background is a freeze frame of the background before tilting.

Create a new composition and name it Comp. Drag the four comps to this new comp and organize them in the following order: Action plate, Flying man, Background tilt, Empty background.

Now in this new composition, select the Flying man layer, solo it and go forward in time one or two frames before the highest point of the jump. Right click on the clip, go to time -> freeze frame. Mask the character using a new solid layer. Use some bright color, like red and make sure the solid is comp size. Now turn down the opacity of that solid to 50%. Draw the mask quite precise so there's no extra halo around the character. Once the mask is done copy it and paste it on the Flying man comp. You can now turn off or delete the red solid.

At this point we want to match the transition between two main plates: Action plate and Flying man. This is a very important part. The transition needs to be seamless. Drag the end point of Action plate so that its last frame is the one before that frame you masked. Keep the still background visible.
Now animate some preliminary movement for the flying man. Go to the first frame of your flying man layer and create a keyframe for position. Go forward couple of frames and move the composition up so that it's just of the picture. Now adjust the posiotion of the keyframe
by moving it forwards or backwards just to get the motion look correct. You want it to look smooth not fast. Try to maintain the speed of the original jump.

Now we match the camera tilt to fake perspective. Go to the Background tilt comp. Apply effect -> time -> timewarp. I used these settings: method -> frame mix; adjust time by -> speed; speed -> 500. You should adjust the speed to match your scene. You don't want to make it too fast. Just fast enough. Go back to your main comp. We need to fit this with the plates. Drag the comp so it starts at the point where the Flying man layer moves of screen. You also might need to adjust the starting frame of the tilt layer to get it fit smoothly. To avoid getting blank frames you should have the empty still of the background under these layers.

In your main composition make only the Flying man layer a 3D layer and create a new camera. A 50mm camera works nicely. Match the camera rotation to your tilting footage. This doesn't need to be accurate. Just use an estimate degree. I only rotated it 16 degrees. Animate the rotation to start couple of frames after your tilt movement starts and ending on the same frame with the movement of your live camera. Also easy-ease these keyframes by selecting them and hitting F9. This smoothens the movement a little.

Because we added the camera, we have to modify the animation we did with the Flying man layer. Select the layer and hit p to reveal the position data. Delete the second keyframe. Go to the last frame of the camera tilt and move the flying man comp in x, y and z axis to about these numbers x= 500 y= 1800 z= 3300. Move forward in time and add another position keyframe with x= 3100, y= -3000, z= 5200. These are the numbers I used and might not work for you. Adjust them to fit your needs. You'll also need to adjust the position of the keyframes to achieve a smooth motion. Animate Z rotation from 0 to 80. First keyframe few frames before and second few frames after the second position keyframe. Adjust if need be. You can also modify the motion path. Select the flying man layer, this should reveal the motion path. Hit p, and select position. This should bring out these handles you can use to smoothen the motion curve. Find the motion you want. Turn on motion blur for the layer and composition. Go to composition -> composition settings, click on advanced and make sure the "shutter angle" is 180. This way the layer won't blur too much.

Now brighten up the character as he moves further against the sky. Use curves editor. Also feather the mask and use negative expansion. Animate these and adjust the keyframes to get the result you want.

Drag your Comp into a new composition. Create an adjustment layer and apply timewarp. Creating this timewarp effect can be tricky. You just need to patiently manipulate the position of the keyframes. First make sure the speed is at 100, method: frame mix and adjust time by: speed. Go to the spot where your character starts to move down. Create a keyframe speed 100. Go forward to the spot where he's almost down and change speed to 200. Move few frames forward create a new keyframe for speed 20. Again move forward to where the character starts to go for the jump and change the speed to 300. Finally when the camera starts to tilt change the speed back to 100. As said, you have to adjust the keyframes to achieve the perfect motion. You might want to leave a bigger cap between the 20 and 300. It gives you a smoother acceleration.

When the keyframes are in position change these settings to the timewarp: Method: pixel motion; under motion blur: enable motion blur; shutter control: manual; shutter angle: 180; shutter samples: 12.

Render the comp. I recommend you use Quicktime photo JPEG.

I would also like you to know that this was the very first tutorial I've written. I hope it is informative enough to help you create your own Flying Man.