Simulating ink in water

[Toby Nowland-foreman]

I filmed food colouring being dropped into a fish tank in front of our green-screen, it works great and is an awesome cheap alternative. You can check out how I did it here and download my pre keyed final shots for free here: https://blog.metanation.com/rec-room/2010/05/07/green-screen-fire-water-ink.html

[John Paterson]

The best way I’ve found is to use video footage of cigarette smoke, shot against a black background. You should be able to find some online. The first thing to do is create a new document in aftereffects and import the smoke footage into the timeline. Smoke rises, so rotate the smoke layer by 180 degrees so that it now falls like ink. Create a new black layer and move it to the bottom of the composition. If you want to have blue ink on a white background, create a new yellow layer positioning it between the black layer and the smoke layer. Select the yellow layer and then click on the TrkMat control and select “Luma Matte” so that the smoke becomes yellow. Select all layers and then select Layer>Pre-Compose then OK to flatten the layers. Then select Effect>Channel>Invert and there you have it, blue ink against a white background.