Lesson 2

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  • Matte painting
  • Nuke to Photoshop
  • Use of camera
  • Animated rotoscoping

Content

In this lesson, matte painting will be introduced. This will call upon a simple set of Photoshop (PS) skills. At its simplest level, a matte painting can be integrated into live action footage using no more than a simple Merge node. The art of matte painting is making a painting that blends perfectly with the live action footage. This isn't as difficult as its seems, and I will give you tips in class.

There are many examples of good Matte painters on the internets. I will leave you to find them using your Googlefu. However, Brandon Kachel's website is very good as he shows us the before and after shots of his work (be aware: the rollovers take time to load).

The basic matte painting workflow is as follows:

  • First review the footage. Is the camera moving at all? Is so, then the movement will need to be tracked, and the resulting tracked motion transferred to the matte painting.
  • A single frame from the footage will need to be rendered out as a 16 bit tiff. This matte render will serve as the basis for the matte painting. If the camera is fixed, then this frame can be rendered from frame 1. If the camera is a pan shot, then a suitable frame will need to be identified. This frame should accommodate as much of the intended painted region as possible.
  • It is possible that the matte painting will be larger than the format of the footage. This is called 'overscan', which I will explain in class. In brief, it make the workflow a bit more complex.
  • Track the footage, with the Tracker. A tracker requires a reference frame, which is a frame that is treated as the start point by the tracker (i.e. 'zero movement'). For a smooth workflow, the reference frame should be the same as the matte render.
  • From the tracker will be derived a match move, which is no more that a Transform node the values of which are linked to the Tracker. Simply... this task of this match move is to pass the motion of the footage onto the matte painting.
  • The match move should be tested. Testing need require no more than connecting a texture to the match move, laying it onto the footage, and seeing if its motion matches that of the footage.
  • Using the matte render as the starting point, the matte painting is made in Photoshop (PS). For technical info on PS, you might wish to visit my Photoshop Wiki, here, especially this page, which gives a quick lowdown of key PS technical skills.
  • The page Photoshop Workflow describes the workflow between Nuke and PS. The basic philosophy is to do the matte painting in a master file, and save flat versions for import into Nuke. This makes versioning a lot easier.
  • Grain and motion blur are added to the matte painting so as to match the footage. See the page on Integration for details.

A large matte painting looks more convincing if it is animated in some way e.g. If some birds have been animated flying across a matte painting of a sky. This and other aspects of the aesthetics of compositing are discussed here.

A matte painting can be made to look more realistic if some live action element overlap it. Overlap is discussed here. In order to do this, a section of the matte painting will have to be selectively masked out. This will require that an animated rotoscope is made, which is discussed here. The rotoscope alpha (i.e. a mask) with have to be combined with the alpha of the matte painting. Combining alphas is discussed in this page.

Assignment: matte painting

You are to take a shot of scene that features a wall or the ground. There should be no camera moment. In this class, we will be using the CANON 70D. Take these out from the stores, together with a tripod and a spare card. When shooting the footage try to consider the framing, the lighting, the camera angle etc. It will help if first you take many test photos: to experiment with different solutions. The golden rule: that it will look good. A general introduction to camera basics is here, and a walk-through of how to use the CANON 70D for shooting movies is here.

By the use of a Photoshop to Nuke workflow, you are to make a matte painting to give the impression that the wall or floor is distressed in some manner. This might involve adding some dirt, a crack or a hole.

If you want to be a bit ambitious, you might want to include a figure. If they walk past the scene, the matte painting will have to be masked out using a Roto node. I will show you how to do this in class, but it will call upon the Combining Alphas skill set.

When making the painting, sourcing effective textures will be important. I highly recommend getting a paid account at textures.com.

Assets

Assets for Lesson 2
Name Description Link
Matte Painting (01) A reasonably simple Matte Painting used in a Nuke script. The script has been 'flattened' (all animations removed and all movies rendered as single frames). Contained in the project folder are: a Nuke script (.nk), a master painting file (psd) and various source files. Download (50mb)
Matte Painting (02) A more complex matte painting. Download (160mb)
Matte Painting (03) Tracking, grain and motion blur added to a matte painting. Download (260mb)
Matte Painting An example of a complex matte painting (psd) Download (128mb)