Fades and mixes

DreamShow moves the light from one state to another in three ways, which do not behave in the same manner: the scene fade (when going from one scene to the next), the block fade (its rise and fall) and the mix (two blocks that overlap on the same track). Telling them apart avoids unpleasant surprises: a moving head that jumps instead of gliding, or a colour change that makes a dip.

To open it: the scene fade is set in Scene settings, field Fade to the next (s):. A block's fades are set in its Properties… window (right-click on the block). The mix is made by overlapping two blocks on the same track of the Scene timeline panel.

In summary

Channel families

To know what “fades” and what “jumps”, DreamShow sorts each channel of each fixture into a family, from its definition in the fixture library:

• Intensity: dimmer, colour mixing (red, green, blue, white, amber, UV, cyan, magenta, yellow…), cells of a bar or matrix.
• Continuous parameters: pan, tilt, zoom, focus, iris, frost, and a simple colour channel (a level from 0 to 255 with no named positions).
• Discrete parameters: shutter and strobe, colour and gobo wheels, prisms, macros, and all the other channels.

16-bit channels (pan and fine pan, for example) are always handled together, as a single value: a moving head does not shake during a fade.

The scene fade: “Fade to the next”

The Fade to the next (s): field belongs to the scene you are leaving. Its tooltip: “As in ppshow: length of the fade applied when LEAVING this scene (on GO or automatically), towards the state of the next scene. The timeline of the next scene starts when the fade ends.”

What happens on GO (or on automatic chaining):

1. DreamShow starts from what is really on stage at that instant (final state of the scene being left, plus the blocks still active).
2. For the length of the fade, everything glides towards the final state of the next scene:
   • intensity and continuous parameters pass gradually from one value to the other (the moving heads move during the fade);
   • discrete parameters take their new value at the start of the fade; if they go to 0 (shutter closed, wheel at rest), they only change at the end, so that the light does not disappear before its intensity has come down.
3. At the end of the fade, the next scene's timeline starts at 0 s.

During the fade, the editor and the cue window show “fade 2.4 s” (remaining time). The cue window also recalls a scene's fade (“→ fade 5 s”).

What does not fade: choosing a scene in the editor's Scenes panel, ◀ Previous in the cue window, a Go to scene… block, resuming after a crash. These jumps are instantaneous.

The videos of the scene being left stop at the start of the fade; the sounds carry on (see Sound and video on the timeline).

The block fade

Fade in (s) and Fade out (s) set the rise and fall of a light, effect, trajectory, dynamic effect or pixel mapping block. They concern intensity only:

• the block's intensity rises from what is underneath during the fade in, and falls back to it during the fade out;
• position, zoom, wheels and shutter take the block's value from its very first instant, and keep it until its end.

This is deliberate: a moving head gets into place while its light rises, instead of sweeping across the stage; and a shutter never runs through its strobe values.

The fade out ends at the end of the block. The sum of the two fades never exceeds the block's length.

The mix

When two light or effect blocks overlap on the same track, the first blends into the second, like two clips that overlap in a video editing program. The timeline draws a cross on the overlap.

During the overlap:

• What both blocks set (the same channels of the same fixtures) glides from the first block's value to the second's, whatever the channel's family: intensity, colour, position, zoom… The first block stays at full intensity during this time (no dip in the middle).
• What only the first block sets fades out during the overlap: its fade out is replaced by the length of the overlap.
• What only the second block sets rises during the overlap: its fade in is at least the length of the overlap.

The mix only happens between two consecutive blocks of the same track. On two different tracks, two blocks do not blend: they are layered (see Light and effect blocks).

Other overlaps also make an automatic fade, each within its own family:

• two sounds on the same track: crossfade (see Sound and video on the timeline);
• two Sound level blocks on the same track: the level passes from one to the other;
• a Blackout and a light on the same track: the light goes down to black or comes back up from it.

Examples

A colour that slowly turns

“Cyclo” track: block A, red cyclorama at 100 %, from 0 to 10 s; block B, blue cyclorama at 100 %, from 8 to 20 s. → From 8 to 10 s, the cyclorama goes from red to blue through purple, without dipping. The cross covers 8–10 s.

If B is on another track (lower down), there is no mix: at 8 s, B is laid on top of A. With no fade in, the cyclorama goes blue at once; with a fade in, the colours' intensity glides towards blue during that fade.

Moving heads that glide from a singer to the piano

“Moving heads” track: block A, heads aiming at the singer, from 0 to 15 s; block B, heads aiming at the piano, from 13 to 30 s. → From 13 to 15 s, the heads move from the singer to the piano, with the beam on.

The same without overlap (A from 0 to 15 s, B from 15 to 30 s with a 2 s fade in): at 15 s, the heads jump straight to the piano, and only their intensity comes back up over 2 s.

A day-to-evening change on GO

Scene 1 “Day”: Fade to the next (s): = 8. Scene 2 “Evening”: warmer and lower final state, moving heads repositioned. → On GO, over 8 s, the light goes down and warms up, the heads glide to their new positions. A gobo change, on the other hand, happens at the start of the fade. The “Evening” timeline then starts.

A deliberate “blackout in between”

“Front” track: block A from 0 to 10 s with Fade out (s) 2; block B from 10 to 20 s with Fade in (s) 2, with no overlap. → The front light goes down to the final state (or to black if the final state does not light it) between 8 and 10 s, then comes back up with B's setting between 10 and 12 s.

Step by step: setting a crossfade between two blocks

1. Place the two blocks on the same track.
2. Drag the second block to the left until it overlaps the end of the first by the length you want (for example 3 s). A cross appears.
3. Leave the second block's Fade in (s) at 0 (the overlap does the work).
4. ⏮ then ▶ to check in the simulation.

Good to know

• During a mix, even the colour and gobo wheels, and the shutter, glide from one value to the other if the two blocks set them differently: the wheel scrolls, the shutter may run through strobe values. Give both blocks the same values for these channels, or separate the blocks.
• If the second block of a mix has a fade in longer than the overlap, the fixtures set by both blocks stay at the level reached at the end of the mix; those that only the second block lights follow its fade in to the end.
• In a parallel sequence, two overlapping blocks only make an intensity fade: colour and position change at once.
• During a pause (editor stopped, wait block), the scene fade is considered finished: the editor shows the final state directly.

See also

• Light and effect blocks
• The scene timeline
• Scene settings
• Sound and video on the timeline
• Trajectories
• Glossary