Adobe After Effects is one of the programs most often used by professionals who want to add postworked special effects to either regular video footage or animation. One of the more interesting effects that can be produced in After Effects is to add fog to a scene. For example, if you have footage of a rock concert that could be improved by adding a bit of atmosphere, adding a fog effect near the floor of the stage is a good way to do it.
Preparation
Start by opening After Effects. Then open the project containing the footage to which you want to add the fog effect. Now go to "Layers" and make a new "Solid" layer. Go to "Effects" and add "Fractal Noise" to the "Solid" layer. Now go to "Transform" and change the scale to 600 and the "Complexity" to 155. Go to the "Sub Settings" and make the "Sub Scaling" 50.
Create Motion
Now you need to create some keyframes to create realistic motion in your fog effect. "Key" the "Evolution" setting, and the fog becomes animated. Also "Key" the "Sub Offset" under "Sub Settings" and your fog really starts to come to life. Switch the "Layer Mode" to "Screen." This will reduce the opacity of the fog, making it blend in a bit better with the background.
Localize the Effect
Right now, the fog effect is all over the image when the intention was to have it only at the bottom near the floor. To restrict the effect to a particular area, you need to go to the "Pen" tool and use it to create a mask. Adjust the mask and its points so that the effect starts at the bottom and stops roughly mid-way up. Now in the options, adjust the "Feather" of the mask so as to produce a soft, fading edge to the fog. Otherwise, it will have an unrealistic edge to it.
Finally, go to "Effects" and select "CC Toner." Using this effect, select a new color for the midtones by picking ones from the image, specifally from the area covered by the fog. This will produce much more realism in the fog effect.
Tags: After Effects, near floor, Solid layer, This will
