Compositing Project 3

01 – Live Action on Live Action

Combining these two videos:

This is the shake tree:

First we key out the green screen with chroma key, adjusting the sliders while viewing the alpha channel so that only the figure is white. In this video, since the figure will not move, instead of creating a garbage matte, it is easier simply to crop the video.

Then we go ahead and overlay it over the background video and adjust the huecurves for green suppress, looking at the background video. Noticing the quality of the background video, also added a SMALL amount of defocus and some pixelation and FilmGrain.As an example of how much different it would look compared to the original:

to

Now we scale him, referencing the people in front of and behind him and move him into position. Notice that there’s not enough space between the man and the 2 girls so we will have to roto him. We create 2 rotoshapes for the man: 1 for the head and the other for the body, since one will not change nearly as much.

Now since the movement of the escalator is constant and perspective is of a minimal factor, you can simply keyframe the first frame and last frames for scale, and it will interpolate in between. The position, on the other hand, will need more work since you will need to nudge the figure sidways so his hand stays on the railing. Simply move him into every 20 frames or so and keyframe. Be sure to look at the actual escalator stair he is standing on and make sure he stays on that stair.

Now the result:

02 – Render on Live Action

Combining this render animation with this video:

This is a closeup of the model, an extremely simple ufo:

This is the tree:

We start by simply overlaying the ufo with the beach and aligning the animation to what we want. This will be a simple composite–the object floats and is further in the background, freeing you from the burden of detail (and lack of modeling skill).

First we colorcorrect and find that not much adjustment is needed–only a little darkening and slightly increasing the blue.

Then we create a matte for the house that the ufo flies behind:

We find that the background video’s camera is actually moving so we will need to animate the rotoshape just a little–for the 5 frames or so the ufo is in contact with the left and right sides of the building.

Now we have the ufo, but we need a shadow or else it really will be “floating” over the picture:

You can probably tell from the tree that I originally intended to use a drop shadow but since the water is a flat plane and the ufo moves towards and away from it, it doesn’t actually work out. Therefore, I roto my own shadow again with a dark green color so I can control the way the shadow moves. We animate the movement to follow a little behind that of the ufo due to the direction of the light. Remember when the ufo dips down closer to the water, the shadow will move forward and vice versa as well as grow darker and lighter.

Now the result:

03 – Live Action on Render

Combining this video with this still render:

This is the tree:

Note that there are a lot of node groups for the shadows, will cover those soon.

This time the figure is moving so we can’t simply crop so we make a garbage matte for the lights:

The bottom left one will be animated when the figure’s legs cross over.

As always, color adjust the video and add defocus/pixelize as necessary. Since our background is a render, we won’t need as much filtering on one, but I added a little to both to try to make them fit more together.

The main issue with this one will be the shadows, as they are very visible in the render. Here are is the tree’s shadow groups expanded:

And here is a sample of the result overlaid on top of the original video to show the relative placement and effects of the garbage and holdout mattes:

The wall shadows are easiest, we simply reposition a drop shadow and adjust color and opacity to match those in the render and add a holdout matte. I created different ones on the different walls as they will have different properties due to their angle. Also, note that since the render shadows are hard-edged, we reduce fuzziness on our shadows to 0.

For the ground shadow, the perspective is much more obvious. At first I had been using a Warper node, but that did not work out past a certain point, so I made another ground shadow group that “takes over” past a certain frame using the CornerPin node. Remember to keep the feet of the shadow touching the feet of the figure and the legs connecting to the shadow on the walls.

I also quickly roto’d the shadows on the streetlight using the same animation principles as in the ufo composite.

The result: