[LCtalk] Submaster Fader Implementation Idea

[Jay Weathers]

Several responses have been posted to this talk-list regarding the 
ability to have submaster faders, especially from DMX Input. There are 
many reasons for this request; it's a feature on conventional lighting 
boards, it helps when working a live show that doesn't conform to rigid 
programming (although the LanBox's layers are very helpful), it can help 
with some light fixtures/control, and many more. For example, we have 
some LED lights that don't have an intensity channel. It is difficult to 
fade these in and out using the master control in LCEdit as the values 
will not change in the same proportion to each other, nor do the values 
retain the same proportion and return to their original values when 
brought back up. Therefore, the color of the light changes instead of 
the intensity. In addition, I would like to be able to bring all the 
lights in a group down together with the LED lights without creating a 
large number of lists (one for each color being utilized on the LED 
lights and final intensity level) that all do essentially the same 
thing.

Given my understanding of how the LanBox works, it seems that two 
changes could implement this feature.
  1) The first issue is mapping a DMX Input Channel to more than one 
Layer Channel. This could be done just like the DMX output mapping where 
you can select which Mixer Channel feeds each DMX Output Channel. Just 
in reverse, select which DMX Channel feeds each Layer Channel for the 
selected layer. Slightly more complicated than a channel range but there 
should be some reuse of the DMX Output mapping code. So, for example, in 
layer D, Channels 1, 3, 4 and 8 could be mapped to the value of DMX 
Input Channel 1; Channels 5 and 6 could be mapped to the value of DMX 
input Channel 2, etc. This allows for one input to effect several 
internal channels.
  2) The second part of the picture is applying the value to the Mixer 
Channel stream. Since it is desired to have the submaster bring the 
values up and down in proportion (0-100%) to the channel values in the 
mixer, it is essentially applying a percentage to the value. In other 
words:
        NewMixerChannelValue = UnderlyingLayerMixerChannelValue * CurrentLayerChannelValue / MaxChannelValue
              Where UnderlyingLayerMixerChannelValue is the value as a 
result of the layers under the layer being applied
                    CurrentLayerChannelValue is the value of the channel 
in the layer being mixed in with percentage mixing (in this case, also 
the layer where the DMX Input values are applied.
Both seem fairly straight forward for the Lanbox. Neither of these 
changes would be a large change to LCEdit. The first change would 
actually remove part of the DMX Input options and only need the Layer 
identification. The second would be adding a mixer option.

In addition, internal submasters could be created if another buffer was 
created (I'll call it SubMasters) and a similar mapping ability was 
implemented. Here, in a specified SubMaster Layer (like the specified 
DMX Layer), the mapping specifies which SubMaster Channel feeds each 
Layer Channel. Although this is a little more complicated to implement, 
this would be very powerful. (I can hear the competition quivering and 
the users saying "yea".)

Keep up the great work.
	Carey Weathers