One of the first things this week was to remind myself how to roto out shapes of people in my footage, specifically the ones where there are people in front of the camera with the sound system and subsequent cymatics behind them. So, back to digital tutors and a short course on rotoscoping and creating mattes:

Master Rotoscoping

Lesson 2 Drawing Basic Shapes

  • Roto node – Bezier tool – draw shape
  • You can have several Bezier shapes within the one roto node
  • Will highlight the frames with blue keys

Lesson 3 – Editing basic shapes

CTRL key+ LMB over a control point will break the Bezier handles

  • Or, add points
  • If you have a point that needs smoothing, use smooth points tool to add Bezier handles (behind the add points tool)
  • Cusp points takes it back to their original drawn point

Lesson 4 – Drawing a complex shape

Hand example

  • First drop in the roto node – draw the shape of the palm of the hand
  • Name the Bezier shapes as you go as there will be 6 all together
  • Draw fingers, using the same roto node – make sure the shapes overlap – name them
  • [Week 32 Image 1]

week 32 image 1

Lesson 5 – Animating masks for rotoscoping

move to the frame you want where the shape has moved (extreme frame – furthest away)

  • select the line from the roto node (if you have a list of them) – it will highlight the line in dots
  • drag mouse around it to move – you’ll get the 4 pointed arrow like you do in transform
  • move and rotate to suit in the frame you’ve moved it to
  • any points that are out, move individually to match
  • it’s ok for the shapes to overlap

Lesson 6 – Controlling the shapes edge and opacity

if you have motion blur – to get feathered effect

  • click on the point with the little perpendicular line coming out – click and drag on the line and you’ll see a dotted line coming out [image 2]

week 32 image 2

  • this is creating a feathered line
  • you might have to pull the line up before moving it out, depending on its orientation
  • can always add a cc node, use its mask to connect to the roto so you can see the difference between the masked part and the background [image3]

week 32 image 3

  • also have the option to use the feather and opacity settings on the roto node, but this is more heavy handed – depends if there is a lot of motion blur for example…

Lesson 7 – Merging shapes together to create a cutout

  • 2 bottles example – both on the same roto, but they need to be on different rotos to isolate either one [image 4]

week 32 image 4

  • so, create a second roto node, don’t connect it
  • all you have to do is drag the selected bezier from the root of the selected roto and drag it onto the root of the new one [image 5]

week 32 image 5

  • now use a merge node to join both – it depends on what opreation you choose whether which will be on top etc – the ‘from’ opreation will only affect the B pipe (in this case more colour correction) – [image 6]

week 32 image 6

  • if you connect the viewer to the merge node here, using the ‘from’ operation and selecting the view style to alpha (A), you can see how the alpha channel of the cut out [image 7]

week 32 image 7

  • From = difference

Lesson 8 – Reusing keyframe data with the viewer

  • if you have looping data, you can reuse roto date to save time (bobble head example)
  • frames 1 to 7 have been keyed, after that it loops
  • first off, move to the frame where you want to start copying from – drag a box around the whole roto to select it
  • RMB – copy – 3 curves (spline key values) [image 8]

week 32 image 8

  • then, go to the frame where you want the data to be copied – RMB – paste – 3 curves (values) again
  • adjust any points if necessary
  • drawback of this method is that you have to do it frame by frame, but quicker than redrawing

Lesson 9 – Animating a complex rotoscope with ease

  • create different pieces for different parts of the body (woman waving example)
  • start with the parts that don’t move as much (larger parts)
  • add in keys as necessary to cover movement
  • add in keys and refine

Lesson 10 – Integrating rotoscopes with another piece of footage

  • once you’ve done all your rotoscoping, bring in some footage
  • might be a good idea to roto out some shapes close to camera and blur the background
  • add a merge node
  • B pipe for the background, A pipe plugged into the roto
  • change the operation to matte

Lesson 11 – Outputting masks into an image sequence for later use

  • roto nodes can slow down system
  • pre rendering can speed it up – however, you can also lose data as a result – it depends – check format you prefer
  • bring in a write node (still using woman waving example)
  • plug in the write node to the roto node
  • you can tell if an original piece of footage has an alpha channel because the coloured squares at the bottom of the footage would also have a white square as well as the rgb squares [image 9]

week 32 image 9

  • in the write node, choose the alpha channel from the channels drop down list
  • the alpha will appear as red because nuke just drops it into the first available channel, in this case red – if you changed the view style from the drop down list above the screen, you wouldn’t see anything in the green, blue or alpha channels (becasue they’re empty), you would see a white version of the mask in the red channel – it stores the info as black or white in rgb before the computer assigns a colour to it
  • save the file as a png or exr, depending if you want totally lossless or not – add in hash signs for the file size numbers for the sequence [image 10]

week 32 image 10

  • read in the saved sequence
  • disconnect the A pipe from merge to the roto
  • you don’t need the roto and write nodes now, but you could move them out of the way and leave them visible if you want [image 11]

week 32 image 11

  • we want to copy the read node to become the alpha channel for the original footage
  • bring in a copy node – hook up the viewer to the copy node (error!)
  • we want the original images to be the background so drag the B pipe onto the footage
  • A pipe onto the read node with the alpha
  • in the copy node, select the drop down ‘copy channel’ and select the – now you’ll see on the copy node a little white square indicating the alpha [image 12]

week 32 image 12

  • now drop the A pipe from the merge node on to the copy node
  • change the viewer to view from the merge node to see the results [image 13]

week 32 image 13

Applying the knowledge to my own footage

week 32 image 14

Following the lesson from digital tutors, I applied and modified slightly what I need to do for masking out people from the footage to allow the cymaglyphs to go behind them (who happen to be in the foreground) and in front of the boom box and other objects in the background etc.

So, I have used the roto techniques in simple form as follows:

  • rotoscope the shapes as necessary and keyframe them – one node should suffice
  • add in a colour correct node to see that difference if you want (cc goes directly into the footage, while its mask goes into the roto)
  • one completed, write it out as exr or png file (in channels, select alpha)
  • read back in
  • add in a copy node (or shuffle) and copy either the red channel of the mask to the alpha of the footage, or alpha to alpha (depending if the original footage has an alpha channel already)
  • B pipe of the copy node to the footage
  • A pipe to a merge node using matte as the operation
  • viewer connects to the merge node
  • I used a constant as a background to check, then a colour correct in a second example to note that I can use the A and B pipes on the same footage
  • [images 15 and 16]

week 32 image 16 week 32 image 15

  • the roto and write nodes are not needed now
  • Finally, as a possible set up for the remainder of my shots where I need to fit in the cymatic images between the mask and the background, here is a pipeline that works (although i’m sure there’s a better way!): [image 17]

week 32 image 17

Maya – Creating CymaGlyphs

Continuing with the creation of the glyphs, I seem to find a commonality between them, in terms of their ‘trumpet’ like or ‘flower’ like shapes that make up the interior. Clearly the gemoetry changes from frequency to frequency, but whether it’s five-fold, six-fold, seven, eight or ten-fold, there always seems to be connecting tube-like entities that form from the centre outward with tunnels or holes to the outer shell. I have been using circles of varying size to form a profile shape for one of these shapes, then lofting it and using Mash to quickly create copies and distribute them in a spherical arrangement before baking down the shapes to 1 frame and adding in any other features.

Cymatics HD for Glyphs (0-01-51-00) week 32 image 18

One important question, amongst many, is – “how long do I spend on making these as accurate as the photos are?”. The reason being that when I animate the glyphs together, they’ll be changing rapidly and therefore some of the detail may be unnecessary. It will probably come down to where I stand nearer the end of the project, and if I have time to tweak and add as much as I can.

I have identified which glyphs belong to which musical note, through the process of running through the footage frame by frame. In addition, I have also identified some chords – the idea now is to create all of the glyphs, if I have enough time, and sequence them in the appropriate order along with the music in the same manner that they are imaged in the cymascope. Here are a few examples of the identified glyphs (In order left to right – A, C, D, E, F, G):

A C D E1 F G1