Webcamoid provides a good number of real-time video effects that you can apply to the video sources.
You can open the video effects panel in Main menu/Effects.

Press Add effect to add a new video effect.

Then press and scroll the combobox until you find an effect of your interest.
By default, when you select an effect, it will replace the previous one, if you want to apply the new effect over the previous one you must turn on the Chain effect option.

In the same dialog you will you will find all available options fort he video effect. You can also modify the effect options once applied by pressing it in the effects panel.