Sunday, 27 January 2013

Learning Silhouette #3 - Master Rotoscoping with SilhouetteFX

I've already completed 4 exercises of the DVD (outcomes on my blog - part #1, part #2)

I've finally worked through the rest of the 6 hour DVD course by Ben Brownlee.

Here are another 4 exercises: 

Exercise 5 - Articulated Motion (40:43 min)
Project objectives:

  • Why not to use complex shapes.
  • Analyse human movement and see where the trouble areas will be.
  • Track out camera movement.
  • Handle tracking when the object becomes obscured.
  • Create roto splines for legs and how to create simple seamless masks.
  • When to reshape the spline instead of moving it.
  • Further techniques to deal with motion blur

  • complex shapes cause problems, it is difficult and irrational to animate them. better to break geometry into simple shapes
  • views in SilhoetteFX are very useful tool
  • transformation shortcuts Q - transform, W - rotate, E - scale
  • Tracking. If tracker points interrupt by objects, move it to another area on the same plane and keep tracking.
  • very important to analyse your shot, analyse objects and brake down them into different simple elements.
  • don't forget to activate motion blur in node tab, otherwise it won't work. motion blur with shrink/grow can give better results (in some cases)

Exercise 6 - Planar Tracking (24:24 min)
Project objectives:
  • Add new format presets to suit your workflow.
  • What is Planar Tracking?
  • When is Planar Tracking most useful?
  • What are the best shapes to track.
  • Stop fighting problem tracking data.
  • Learn to separate tracking and shape data.
  • Speed up your roto when objects distort.
  • add new formats in silhoettefx/resources/formats. open via notepad.
  • planar tracking is a whole series of points. It's trying to follow where those points are going and  makes average movement out of that.
  • planar tracking is useful when you have clear 2d plane
  • to speed process up it is better to switch on foreground view
  • order that will save your time ---> draw rough shape -> track it -> then draw final shape
  • when tracking don't forget of channels!
  • you have to be aware of planar tracking limitations

Exercise 7 - Spinning and Occlusion (37:17 min)
Project objectives:

  • See the problem with objects that spin or turn.
  • Find areas to track when the more obvious places are unavailable.
  • Break down the elements in a face, to easily deal with objects that disappear and reappear.
  • When you should add more shapes instead of using existing ones.
  • Use Multiframe to correct errors made across an entire section.
  • Occlusion - shapes are disappearing out.
  • Spinning - objects are changing drastically from frame to frame. 
  • if there are no obvious tracking points it is useful to find them in other places. Keep in mind parallax.

Exercise 8 - Keying (25:42 min)
Project objectives:

  • Revisit the Golden Threads to see why using a key often makes more sense than manual rotoscoping.
  • Explore the different types of key available.
  • Create a slap comp to check your work.
  • Combine keys and roto splines.
  • How to layer your shapes to do the least work possible.
  • Improve your result by using multiple keyers.
  • Find the limitations of the keyer and what to do after that.
  • Mattes - generating through procedural techniques (ex. keyer)
  • Masks - hand drawn ( ex. by hand roto)
  • wrap - blureing inwards (excellent for light wrap)
  • Color suppression works only with blue and green screens
  • black - key, white - leave
  • aware of limitation
  • use garbage mattes
  • layer order can save working time

No comments:

Post a Comment