Alriyami's Weblog

15th May 2008

15 May 2008 Leave a Comment

by alriyami in After Effects

We looked at a few techniques for test animation today. We followed an online tutorial to produce the following. We changed bits of it to make it our own.

We then looked again at displacement maps. We used a displacement map to give the impression of a picture underwater. We used this effect to create the water pool in the swimming pool tutorial we designed a few weeks ago.

A displacement map, works by distorting the layers beneath it depending on the colour information in the map. We first created a fractal to resemble water. We did this using the “string” type in the fractal noise settings. We created two of these layers and made one layer and Overlay. We then precomposed these to use as our map.

We then created an adjustment layer and added a displacement map effect to it. We then used the map composition we just created as the layer map. We then turn the opacity of the map compostion down to around 20%. This is the finished result.

monday 12th May 2008

12 May 2008 Leave a Comment

by alriyami in After Effects

Today we did some more motion tracking using the leaves the we created on the last lesson. Firstly we went out and filmed some more footage to track. We wanted flat surfaces so we filmed buildings and signs.

We used the same technique as the last lesson, but this time we added a ramp effect to the colours of the leaves. This is the first one we did.

In the next shot, we decided to have a couple of areas where the leaves were growing. The first above the doorway, the next on the big wall next to it. We used the same technique as before for both. For the second, however, we wanted the vines to become transparent when it grew across the window. Do to this, we had to create a travelling matte. We did this by created a new black solid at tracking it to the window using the same technique as before. On the leaves layer, we then selected the new black solid as the matte layer. Here is the final result.

We then wanted to have a transition between the two clips, so we thought we’d use the tree as a wipe. We did this in the same way as the window. We created a new solid then added a mask to it that was the shape of the tree. We then tracked this solid to the tree itself.

8th May 2008

12 May 2008 Leave a Comment

by alriyami in After Effects

Today we furthered our work with motion tracking by looking at perspective corner pin tracking. Using this method, you can track the 4 corners of an object. We decided that we wanted to create the impression of 2D leaves growing over a sign. Firstly though, we had to create the animation of the leaves growing. We downloaded a stock picture of some flowers and in Photoshop separated the flowers, leaves and vines onto separate layers. We then animated these items using strokes and scale keyframes. This is what we came up with.

We went out and filmed a simple pan past a parking sign to use as our footage. This is that footage.

The first thing we had to do then was track the four corners of the sign. We then applied this track data to the precomposed flowers layer we’d created. To add more to the image, we used a lens flare effect. We also used the tracking data to position this.We then decided to create a vine that grew up the pole. We did this by drawing a path and adding a key framed stroke effect to it. We then animated some leaves growing from the vine. We motion tracked to pole to keep the vine in place.

This is the final result.

1st May 2008

01 May 2008 Leave a Comment

by alriyami in After Effects

Today we experimented with motion tracking in after effects. Firstly we recorded some simple footage of the building. We did a simple pan to make the motion tracking easy.

Motion tracking works by selecting a group of pixels and for after effects to look for within a given area. You also select an attach point for objects to hold on to. We selected the top left window because it is a point that remains constant throughout the clip and is reasonably well defined.

Once we had created the track data, we assigned this to a new null object. This would be the point that the rest of our footage would follow.

We then created some simple smoke the same was as we did in the titanic title sequence. We used the particle playground, gaussian blur and tritone effects to create the effect. We then attached this smoke to the null object and adjusted the anchor point to make the smoke appear as if it was coming from a window.

28th April 2008

28 Apr 2008 Leave a Comment

by alriyami in After Effects

Today we looked at displacement maps. To do this, we decided to create a swimming pool. We wanted to create a room with a swimming pool in it with the water flowing around the pool.

The first thing we had to do was create the room. To do this, the first thing we had to do was create the walls, floor and ceiling as separate images so we could put them together to make a room. We downloaded some textures and edited them in photoshop to make the walls the sizes and shapes we wanted. It was important to remember the size of all the walls so we could put them together in after effects afterwards.

Here are the textures we created.

These are the main textures for the room. We put the pieces together added some lights and animated a camera around the space.

The next thing to do was create the water. We did this by creating another solid, the same size and position of the floor of the swimming pool. We raised it up slightly to become the water level. We then added a fractal to this solid the same way as we created the background in a previous lesson. To animate it, we added the simple expression “time*300″ to the evolution property.

We fiddled with the parameters until it looked like rippling water. Next we precomposed this layer, took it out of the room composition and added it to the main composition. We then added an adjustment layer and applied a Displacement Map to it. We used the water comp as the displacement layer and adjusted the settings to come up with this. We also lowered the opacity of the original water comp to around 20%.

21st April 2008

21 Apr 2008 Leave a Comment

by alriyami in After Effects

Today we started looking at expressions within after effects. Expressions are a form of Javascript used to help animate in after effects. Expressions make it possible for each layer to react to one another and create complex animations when it would otherwise of been very difficult and complicated to do so.

The first technique we looked as was a way to make layers follow each other around the work space. The way we did that was create some code to make the layer look at previous layer and copy its position and scale from a set amount of frames before it.

To do this, we used the valueAtTime function. This gives us the value of a property on a layer at a certain time.

First of all, we created a simple animation of a circle moving around the screen. We then duplicated this layer and switched off the keyframes. We then created a new expression on the position parameter. We did this by pressing shift,alt,=.

The code we wrote was this

thisComp.layer(index-1).transform.position.valueAtTime(time-0.5)

we used the pickwhip tool to select the previous layer to make the writing easier. This code means, look at the layer before this one, and the value of the position of the layer half a second ago. We added the same thing to the scale parameter.

Once we had done this, we simply duplicated the layer 10 or so times. This gave us this animation.

The next thing we looked at was using “sliders” and variables within out expressions. This technique enables us to change numbers within our expressions without having to go back type in new numbers. This can save a lot of time. To create a new slider, firstly, we create a null. We then add a new slider to that null from the effects and presets box making sure we name the slider something memorable.

The next thing to do is turn this slider into a variable within our expression. We created two, one for horizontal and one for verticle distance. To make a variable linked to the slider called “H” and “v” we use the following code.

H=thisComp.layer(“Null 1″).effect(“H”)(“Slider”)

v=thisComp.layer(“Null 1″).effect(“v”)(“Slider”)

All we type is “distance=” then pickwhip the slider we created. This creates the variable we can now use in our expression.

The following is the expression used to create a slider that changes the distance of layers on top of each other.

H=thisComp.layer(“Null 1″).effect(“H”)(“Slider”)
v=thisComp.layer(“Null 1″).effect(“v”)(“Slider”)

thisComp.layer(index-1).transform.position+[H,+v]

We then keyframed the sliders and came up with this.

We then combined our knowelege of variable and sliders to come up with the following animation using the brightness effect. The code written worked so that the further the layer was from the first layer, the darker the layer was.

The code for the brightness effect is as follows…

a=thisComp.layer(“yellow”).transform.position[0]
b=transform.position[0]

0-(a-b)/

We then did the same thing using the blur effect.