VFX1 DD1410: Rotoing And Colour Correcting The Shadow and Windows

This post continues on from where the last one ended. If you did not see the last post, check the link below:
http://www.darthspockvfx.blogspot.co.uk/2012/11/vfx1-dd1410-rotoing-car-merging-footage.html

To begin, the shadow needs to be roto'd. It is easier to roto the wheels along with the shadow because it guarantees that there will be no gaps between the wheels and the shadow.

 Next the roto needs to be brought into the current merged footage. To do this another merge node needs to be read in, this node is then linked to the shadow roto and the last merge (the one merging the two colour correct nodes together).

Now that the shadow has been merged, the roto needs to be positioned in its proper position beneath the car. To do this, a transform node is read in.

In its current state, the shadow stands out too much, it doesn't match the car or the background, so the shadow also needs to be colour corrected.

Once everything has been colour corrected, if at a later stage the footage needs to be altered in some way, other nodes can be attached to the second merge node.

For example, a grade node:

In this example, the saturation has been increased:

An obvious part of the car that needs dealing with is the windows, when the car roto is merged it perfectly carries across what was roto'd. This means that the original background (a grassy field) is still visible through the windows.

So the next step is rotoing the windows. This can be done on the original background.

This roto is then attached to the new background. To do this a new read node needs to be read in. 

This ensures that when the roto is merged into the new footage, it will show the gate through the windows rather than the grassy field.

The next step requires a bit of preparation. The windows need to be merged into the new footage, but before that is done, read in the nodes that would be used to colour correct and altar the windows roto, but don't do anything with them yet.

These include a transform, a blur, a colour correct and an edge blur.

Now the windows roto can be merged. Read in a new merge node, linking it from the edge blur, to the second merge.

Now the windows are a part of the new background. Using the transform node, they can be positioned on top of the current windows.

Then using the colour correct node, the windows can be altered to match the colour of the rest of the background, and using a mixture of the blur and the edge blur, it will give the impression that one is viewing the windows through another piece of glass (the front windows).

As a little bit of extra alteration, another blur node can be read in to try and give the car a more definitive focus.

This is the node tree in full for this car alteration piece:

It is important to keep note of what has been done in this piece, because when it comes to doing the car alteration pan shot, the colour correct nodes can be easily copied across. Meaning that a person can spend more time concentrating on the like of tracking (which will definitely be present in moving footage) and not worry about replicating the same results as in this piece.

The blog post about the pan footage is below:
http://www.darthspockvfx.blogspot.co.uk/2012/10/vfx1-dd1410-brief-03-car-colour-correct.html