Saturday, 29 July 2017

Keyframing exposure values in After Effects

All of my animated renders are through the render farm, have been composited in Nuke and the final stage is to put the final composition together in After Effects, adding light rays, blurs etc and to use the Dynamic Link to see the After Effects update in 'real time' in Premiere and then the final edit.

Below are some screen shots taken in After Effects - where I have been key framing the exposure values, luminosity and temperature levels to create similar lighting and warmth levels to match the background timelapse footage sequences....

Thursday, 27 July 2017

Creating a water droplet effect in After Effects

Creating water droplets in After Effects.
I've used three light ray effects to achieve this.
Light ray 1 highlights the ice geometry in Maya (highlighted with the red box below). I've set a key on the start and end of the timeline and moved the centre point, so that the light is animated.
I then applied two more light rays and set a key frame for the position and intensity. Having them staggered, and the intensity increase and decrease, gives the appearance of a droplet forming and then dropping
 Droplet (light ray) falling

Setting a key frame for the contrast/gain settings in Nuke

Setting a key to change the range values in Nuke.
For this shot the iceman melts in the foreground - it's the end shot of the melting sequence and I wanted to play with the opacity, so I set a key frame at the start (highlighted red rectangle on the left of the timeline below) and another at the end and changed the value sliders on the right.
Using the ID passes, I was able to isolate the men, by selecting the rgba_green channel in the ranges of the colour correct node, and apply the transformations.
Image below with full contrast/gain values
 Image below with the contrast/gain values adjusted, which gives the appearance of a fading colour



Saturday, 22 July 2017

DIRECTIONAL LIGHT WRAP....

For one particular shot, there was too much hair noise on the left, which really became apparent when a regular lightwrap was applied....so, if I want the lightwrap to appear from one side only, I can apply a directional lightwrap
Below: Lightwrap matte layer, with a bevelled alpha effect, showing just the light wrap on the left
Composited image, showing the light wrap on the right hand side only
Image below: without lightwrap...there is a visible dark grey line around the edge of the hand, which shows up particularly in front of the lighter background
With the lightwrap applied

See additional notes highlighted in green:

Adding a lightwrap blur around keyed green screen footage in After Effects:
Malcolm Finnie at DJCAD created this great workflow instruction for creating a lightwrap in After Effects.
Essentially this process takes a matte from the foreground image (in the case my green screen footage of Kerry) and creates a duplicated outline, slightly blurred, and reflecting the light levels of the background below (in this case sky).

The process:
You will need a foreground and background on separate layers.
Make sure each layer is pre-composed.
  • Select your foreground layer and add Effects>Blur & Sharpen>Channel Blur
  • Set Alpha Bluriness>1.0
  • Under Edge Behaviour, tick Repeat Edge Pixels
  • Right Click this layer and choose Pre-Compose...(choose Move All Attributes to the new composition)
  • Name it Foreground Blurred


Duplicate the Background layer and call it Light Wrap
Place the Light Wrap layer on top of Foreground Blurred
  • On Light Wrap choose Effects>Channel>Set Matte
  • Set Take Matte from layer > Foreground Blurred
  • Tick Invert Matte
  • Choose Effects>Blur & Sharpen>Fast Blur (depending on your version of AE, search for this in the effects library - it may be listed as obsolete but can still be used)
  • Set Blurriness > 30
  • Tick Repeat Edge Pixels
  • Set Transfer Mode > Add
  • Adjust Opacity as necessary
  • Duplicate Set Matte and move to the bottom of the list
  • Untick Invert Matte
Directional Light Wrap

  • Duplicate foreground blurred
  • Name this layer Light Wrap Matte
  • Choose Effects>Generate>Fill
  • Set colour>black
  • Choose Effects>Perspective>Bevel Alpha
  • Set Edge Thickness>20
  • Set Light Angle to match your scene
  • Select the light wrap layer
  • Set Track Matte>Luma Matte "Light Wrap Matte"



Shot_10 - adjusting the scale of the CG elements

Shot_10 - adjusting the scale of the iceman to suit the live action movement...
and playing with After Effects light rays effects, applied to the .exr CGI footage
Original playblast version.

Friday, 21 July 2017

AFTER EFFECTS: Adding a lightwrap blur around keyed green screen footage

Adding a lightwrap blur around keyed green screen footage in After Effects:
Malcolm Finnie at DJCAD created this great workflow instruction for creating a lightwrap in After Effects.
Essentially this process takes a matte from the foreground image (in the case my green screen footage of Kerry) and creates a duplicated outline, slightly blurred, and reflecting the light levels of the background below (in this case sky).

The process:
You will need a foreground and background on separate layers.
Make sure each layer is pre-composed.
  • Select your foreground layer and add Effects>Blur & Sharpen>Channel Blur
  • Set Alpha Bluriness>1.0
  • Under Edge Behaviour, tick Repeat Edge Pixels
  • Right Click this layer and choose Pre-Compose...(choose Move All Attributes to the new composition)
  • Name it Foreground Blurred


Duplicate the Background layer and call it Light Wrap
Place the Light Wrap layer on top of Foreground Blurred
  • On Light Wrap choose Effects>Channel>Set Matte
  • Set Take Matte from layer > Foreground Blurred
  • Tick Invert Matte
  • Choose Effects>Blur & Sharpen>Fast Blur (depending on your version of AE, search for this in the effects library - it may be listed as obsolete but can still be used)
  • Set Blurriness > 30
  • Tick Repeat Edge Pixels
  • Set Transfer Mode > Add
  • Adjust Opacity as necessary
  • Duplicate Set Matte and move to the bottom of the list
  • Untick Invert Matte
Image below showing the After Effects UI with the various light wrap instructions and effects highlighted in red.

Tip: Play the timeline to watch out for hair noise. I didn't notice hair noise in the static images, and then needed to go back and adjust the black and white clip planes in the Keylight 1.2 process and then pre-compose again, to get a clear image.


After Effects: Keylight 1.2. Removing the green screen

Using the keylight effect in After Effects:
Select Effect> keylight 1.2.
Drag and drop the keylight 1. 2 effect (highlighted in red on the right) onto the green screen layer
Select eyedropper tool and click on the green screen
Select 'Screen Matte'
Adjust the black and white clips until the black is completely black and the white completely white.