[LCtalk] Layers stress? [long]

[Fokko van Duin]

Hello all,

As I noticed that for some people the usage of layers is still scary, 
so I'll try to explain in theatre language (in the tutorial we 
explain it in multimedia language).

A LanBox can have up to 31 layers, but what is a layer?
A layer is just as a simple desk with recall of cues, be able to run 
chases, etc


Why should we need more desks?
Well, e.g. to split intensity, moves, colors, gobos over several 
desks. In practice you already see several specialized desks in 
bigger shows, it's far more manageable then one desk which does it 
all. Especially with moving heads, color changers, LED RGB panels, 
and other complex fixtures, it's almost a must.

Imagine that you have a desk for intensities, colors, gobos, effects, 
background lighting, and one for running your show; Then you can 
build the show part by part, each with it's own cues and chases. All 
parts can be tested and changed easily, and you always know that your 
"color desk" e.g layer CA runs only color cues/chases.

If your show becomes really big, you can even decide to have two or 
three intensity, moves, and color desks, each for a group of 
intensities, moves, etc. LCedit+ gives you this flexibility, but it 
must be setup to your preferences.


How are the outputs tied together?
All outputs of the layers (desks) are fed into the mixer with the 
certain priority, and mixed with a certain method. The top layer as 
visible in LCedit+ has the highest priority (so it's independent of 
layer identification letters), and each layer below has a lower 
priority. The priority and mixing method are -only- important when 
you use the same channels in multiple layers, else it does not 
matter. When using the same channels in multiple layers you have the 
priority choice, and mixing mode. Mixing is "Copy" normally into the 
mix buffer, so the highest layer with the same channel(s) wins. Other 
methods are HTP (highest DMX value wins), LTP, transparent, add, but 
it's usage is e.g. for dynamic scaling and positioning of move paths.


How are the layers (desks) identified?
Layers are identified by one or two letter combinations, ranges from 
A-Z, AA-AZ, and BA-BK. Every layer can be named by clicking on the 
advanced.. triangle and type the letters into the ID field.


Does each desk has it's own storage for cues?
No, cues/chases can be made in any layer, but also used on any layer; 
all layers share the same memory pool. This is nice in terms of 
flexibility, but it has the disadvantage that you have to remember 
which cuelists are made for what layer. A simple numbering scheme 
solves this; use e.g. 100-199 only for intensity cues/chases, 200-299 
only for moves, etc.


How do we run cues in different desks at the same time when it's needed?
Very simple; make a control cue which directs your whole (or partly) 
show, e.g.:

// Cuelist 3 (17 steps), stored 29-01-2006 20:06
  -- start  // three cues at the same time
  go 100.1 in layer AI  // start intensity cue
  go 200.1 in layer AM  // start move cue
  go 300.1 in layer AC  // start color cue
  hold for ever         // next control cue (wait for space)
  go 100.1 in layer AI  // change intensities only
  hold for ever
  -- sweeps
  go 200.15 in layer AM
  hold for ever
  go 300.7 in layer AC
  hold for ever
  -- blackout
  go 100.90 in layer AI
  hold for ever
  -- bg
  clear layer AI     // clear layer AI so the background popups
  hold for ever

In above control cue I assumed the following layer setup:

Intensities A:  layer AI  (flash blackouts)
Intensities B:  layer BI
Moves A:        layer AM
Moves B:        layer BM
Colors A:       layer AC
Colors B:       layer BC
Gobos A:        layer AG
Gobos B:        layer BG
Effects A:      layer AF
Background A    layer AB
Show A:         layer AS

This is just an example, I know that near every customer who runs 
bigger shows, has it's own preferences. So if someone has a specific 
other setup, please post it to the list to help "layer newcomers" :-)

--
Fokko van Duin,
CDS advanced technology bv,
http://www.lanbox.com/