How can i create the Agent Smith black tar?

[Steve Roberts]

If I recall the effect correctly:

If you want it to look convincing, you need a 3D app with a 3D model of the actor covered in a shiny black surface.

If you don’t need it to look as convincing, you can try having the actor hold position (or freeze the frame), then draw a mask on a black solid so it matches the shape of the actor. Create a second mask (set to intersect mode) on the black solid and animate its shape so the black shape grows to encompass the actor.
Now if you want it to look shiny, the highlights have to be painted on (maybe using Vector paint) to the black solid. You need to guess where they go, depending on the lighting and the shape of your talent. Illustrators can do this sort of thing.
I said that the talent has to freeze: if you want the talent to move, you need to make sure the highlights move and the black outline moves. If you shoot the actor on bluescreen, you can have the outline of the black shape follow him, but the highlights will have to be painted on frame-by-frame. There’s no automatic way to have them follow his movements without his being a 3D model, with a shiny black surface.

I can’t find any reference to the black effect in Cinefex, but the chrome mirror effect on Neo was a combination of practical goop with a CG reflection effect on a 3D arm model. So you could hang your talent upside-down, shoot bluescreen and pour black goop over him. I’m only half-kidding. 🙂