A Fade cue can be used to adjust the geometry and video effect parameters of a targeted Video, Camera, or Text cue.

Fade cues can also adjust audio parameters of Video cues, Camera cues, Audio cues, Mic cues, and audio output patches. When a Fade cue is selected, the inspector will only show the tabs relevant to the type of cue that the Fade cue is targeting.

The word “fade” can often be taken to mean one thing or another, but in QLab “fade” simply means “change a value over time.”

Fade cues require a cue target or a patch target, have a duration, and must adjust at least one level or parameter of their cue target in order to be considered functional.

The Inspector for Fade Cues

The tabs shown in the inspector when a Fade cue is selected vary based on the more of the Fade cue and its target.

The Basics Tab

The Basics tab is always visible, but has a small but important difference from how the Basics tab usually appears.

Because Fade cues can target both cues and patches, a pop-up menu appears next to the Target field to switch between cue targeting and patch targeting. When Patch is selected from this menu, a second pop-up menu appears which allows you to select the patch that you want to fade.

The Triggers Tab

The Triggers tab is always visible and behaves the same way that it always does.

The following tabs are visible when a Video cue, Camera cue, or are the target of the Fade cue:

The Curve Tab

The fade curve, drawn in yellow on the right side of the tab, determines the rate of change of the parameters being faded. The curve on the left is for levels which increased by the fade, and the curve on the right is for levels which are decreased by the fade.

The horizontal axis of the curve represents time and the labels across the top will change based on the duration of the Fade cue. The vertical axis represents percentage of the total change made by the Fade cue. For the rising curve, the one of the left, the bottom left corner represents the beginning of the fade, which is to say “time = 0, completion = 0%.” The top right corner represents the end of the fade, or “time = (duration of the Fade cue), completion = 100%.” For the falling curve, the top left corner represents the beginning and the bottom right corner represents the end.

The curve shape that appears by default is set according to the Fade cue’s cue template, but you can choose another fade shape from the pop-up menu in the top left corner of the tab.

There are four options for Fade curve shapes:

• S-Curve. QLab’s default curve shape follows an “ease-in, ease-out” envelope designed to sound natural with audio levels and look smooth with video geometry.
• Custom Curve. This option allows you to click anywhere along the fade curve and a create control points, which can be dragged to change the shape of the curve. Moving control points will smoothly bend the curve in the direction of the control point. To delete a control point, click on it to select it and press the delete key on your keyboard. To start over entirely, click Reset to Default Shape in the bottom left corner of the tab. The lock button between the two curves allows you to mirror the left and right curves. When the curves are locked, any change to either curve will apply to both curves.
• Parametric Curve. This option adds a text field labeled Intensity below the pop-up menu which allows you to use a mathematically precise parametric fade shape.
• Linear Curve. This option is similar to the custom curve option but instead of smoothly ending the curve, control points create a precise, sharp bend. To delete a control point, click on it to select it and press the delete key on your keyboard. To start over entirely, click Reset to Default Shape in the bottom left corner of the tab. The lock button between the two curves allows you to mirror the left and right curves. When the curves are locked, any change to either curve will apply to both curves.

Both the rising and the falling curve use the same fade shape type, but if you use custom curve or linear curve you can create individual curve shapes for each.

The Audio Domain pop-up menu is only relevant if the target cue contains audio and if anything pertaining to audio is being faded. You can learn about this control from the Fading Audio section of this manual.

The Levels Tab

The Levels tab will only appear if the target cue contains audio. It behaves the same as the Levels tab for Fade cues targeting Audio cues.

The Geometry Tab

The Geometry tab allows you to specify which parameters of the target cue you wish to fade, and what their final value will be.

The left side of the Geometry tab contains a few setup tools:

The Curve/Path buttons switch the tab between curve mode, which fades the selected parameters (that is, the ones whose checkboxes are checked, and which are colored yellow) according to the settings in the Curve tab, and path mode, which fades two parameters simultaneously according to a 2D path, discussed below.

Clicking the Set Geometry from Target button, or using the keyboard shortcut ⌃⌥⌘V, will invoke the paste cue properties sheet in a special way. First, it will behave as though the target cue was selected and copied, and second it will automatically select the “Video” set of properties to paste. You can choose other properties if you like, but if you simply hit the enter key, QLab will paste the geometry from the target cue onto the Fade cue. This is a convenient way to get started building a fade, as it will help you keep track of the starting point from which you will be fading.

Stop Target When Done. If this box is checked, the target cue will stop once the fade is complete. If the box is unchecked, the target cue will continue to run after the fade is complete.

Absolute Fade. This drop-down menu lets you choose between an absolute fade, which is QLab’s default, and a relative fade. Relative fades are discussed in detail below.

Preview. This button provides quick access and a visual reference to the live fade preview setting.

The center section of the Geometry tab contains controls for the fade-able parameters of a Video, Camera, or Text cue. By default, the checkbox next to each parameter is unchecked which means that the Fade cue will not adjust that parameter. To “activate” a parameter, so that the Fade cue will adjust it, check the box next to that parameter. To reset a parameter to the default value for that parameter, click the :button-reset-alt-5: reset button next to that parameter.

Opacity. You can fade the opacity of the target cue to any whole-number opacity between 0% and 100%.

Translation. You can move the target cue left to right and up to down by fading translation. Change the position of the video along the X-axis and/or Y-axis by entering values in the text fields or by clicking and dragging the thumbnail image in the preview box to the desired location.

Scale. You can scale the target cue in both the X and Y axes together, or individually by clicking the icon to unlock the axes and adjust them separately. You can also adjust the scale by scrolling vertically on the thumbnail image in the preview box.

Rotation. Click and drag on each of the (X), (Y), and (Z) buttons to fade the rotation of the target cue.

3D orientation. By default, Fade cues use three-dimensional quaternion math to rotate their target. This results in smooth, natural movements when rotating along multiple axes, but necessarily means that a fade will never pass through more than 180 degrees of movement in each axis. If you instead want to rotate the target a specific number of degrees about a single axis, you can use this pop-up menu to choose an axis, and then enter the number of degrees you wish to rotate.

The right section of the Geometry tab contains a blue preview box, representing the stage that the target cue is assigned to, and a thumbnail image of the target cue showing the finished results of the fade.

2D Paths

If the Curve/Path switch is set to Path, the other inspector tabs besides Basics and Triggers are disabled. In QLab 5.4, Fade cues can only be used to fade the translation, rotation, and scale of Video, Camera, and Text cues. Then, the Geometry tab allows you to select the parameters that will be faded by the cue, and edit the 2D path along which they will fade. The fade path is shown in the center canvas area of the tab as a yellow line over a blue background. The starting point of the path is drawn in green and the ending point is drawn in red. There are also small directional carets pointing away from the starting point and towards the ending point, to help differentiate these points without relying on their color.

The left side of the path tab contains a few setup tools:

The Curve/Path button is described above.

The Parameters menu lets you select the parameters which are represented by each axis of the canvas view in the middle of the inspector. The default setting is translation, meaning that the X axis (left to right) of the Fade cue represents the X-axis translation of the target cue, and the Y axis (up to down) of the Fade cue represents the Y-axis translation of the target cue.

If you choose to use custom parameters, then each axis of the path can be assigned to any available axis of translation, rotation, or scale.

In the screen shot below, the Parameters menu is set to Custom, then the X-Axis menu is set to Rotation Z and the Y-Axis menu is set to Scale X.

With these settings, as the Fade cue runs, the target cue’s Z-axis rotation will steadily go down, while the X-axis scale will oscillate up and down while trending down overall.

Stop Target When Done. If this box is checked, the target cue will stop once the fade is complete. If the box is unchecked, the target cue will continue to run after the fade is complete.

Absolute Fade. This drop-down menu lets you choose between an absolute fade, which is QLab’s default, and a relative fade. Relative fades are discussed in detail below.

Preview. This button provides quick access and a visual reference to the live fade preview setting.

The center section of the Path tab displays the path and provides tools for you to use to create and edit the path.

The select tool lets you click on individual control points to select them for precise editing:

With one point selected, you can use the text fields in the lower right corner to type in a value or click and drag up and down to adjust the value.

You can also click and drag a selection box around several control points:

The draw tool lets you click to add points to the path, or click, hold, and drag to draw a freeform line. Holding down the option key (⌥) key allows you to add a point in the middle of a path, otherwise each drawn point will be added to the end of the path. Double-clicking while using the draw tool finishes drawing and switches to the select tool.

The circle tool lets you draw a perfectly circular path. The first click sets the starting (and ending) point of the circle, and the second click defines the diameter of the circle. Holding down the option key (⌥) allows you to instead click once to define the center point, and then click again to define the radius of the circle.

Flip vertical flips the selected group of points around the X axis.

Flip horizontal flips the selected group of points around the Y axis.

Rotate spins the selected group of points in 90 degree increments around the center point of the selection.

Reverse leaves the points in the same location, but reverses their order in the path. For example, consider this simple path with two points:

After using the reverse tool, what was the start point is now the end point, and vice versa:

The help button displays a list of the keyboard shortcuts and modifiers for the Path tab.

The alignment menu in the upper right corner of the center area lets you choose where the axis is placed on the canvas. By default, it is placed at the center, both horizontally and vertically, corresponding with QLab’s center origin point for video geometry. However, this menu allows you to place the axis in one of the corners to help achieve your mathematical goals. It has no functional difference beyond how the canvas is displayed, and therefore what sorts of values are easiest to enter.

To the right side of the canvas are a few more controls for configuring the canvas and the overall behavior of the path:

Width and Height allow you set the width and height of the blue rectangle. By default, QLab uses the size of the stage that the cue target is assigned to use, but you can enter any values you like. These values are not a limit; the Fade cue can send values outside the defined range. They are simply tools to help you visualize the extent of the space within which you are fading.

If you were using this Fade cue to fade scale, for example, you may prefer to set the width and height to the maximum scale that you expect to fade to.

Merge percentage. If the starting point of the path does not align with the current position of the target cue, QLab can make the fade smoother by merging the current position of the target with the path. The merge percentage is the point along the path by which the target cue will “catch up” with the path. If the target is very close to the path, a merge may complete before the specified percentage, but it will never complete later.

For example, if the merge is set to 25%, when the Fade cue starts running, the target cue will start moving organically towards the values indicated by the path starting from wherever it is currently positioned. By the time the :fig-fate-2d-5: Fade cue is 25% complete, the target cue will have arrived on the path, and the remaining 75% of the fade will proceed as drawn.

The interpolated path is drawn in green, showing you exactly where the target cue will travel from its current position, indicated by the circle and crosshairs, to meet up with the path.

A higher merge percentage will result in a smoother meeting if the target cue is far away from the starting point of the path, but of course it will also result in more of the movement being off the path as drawn.

Smooth path. When this box is un-checked, paths will be drawn precisely between each control point. When the box is checked, the path will be smoothed between points to create a naturally curving line.

You can use the and buttons to zoom in and out on the canvas. If you’re using a trackpad, you can zoom in and out by placing the cursor over the canvas and pinching in and out. If you’re using a mouse or trackball with a scroll wheel, you can zoom in and out by holding down the option key (⌥) and scrolling vertically.

While zoomed in, you can pan around using two-finger swipes on a trackpad. If you have a mouse or trackball with a middle button (oftentimes the scroll wheel can be clicked; this is usually the middle button,) you can pan around my holding that button down.

The Reset Points button resets the path to the default shape defined by the cue template.

The Audio FX Tab

The Audio FX Tab tab will only appear if the target cue contains audio. It behaves the same as the Audio FX tab for Fade cues targeting Audio cues.

The Video FX Tab

Fade cues automatically recognize video effects added to their target cues, and list all of the parameters of all of the video effects in use. By default, the checkbox next to each effect parameter is unchecked, which means the Fade cue will not adjust that parameter. To fade a parameter, just check the box next to that parameter. Fade cues can adjust any number of parameters simultaneously.

Clicking the Set Video FX from Target button will set all video effects parameters to the levels that they contain in the target cue. This is a convenient way to get started building a fade, as it will help you keep track of the starting point from which you will be fading.

Checking the box labeled Fade rate to, and setting a target rate, allows you to fade the playback rate of the target cue. The maximum playback rate in QLab is 33, or 33× normal speed, and the minimum is 0.03. This control has no effect on Camera or Text cues.

Stop Target When Done. If this box is checked, the target cue will stop once the fade is complete. If the box is unchecked, the target cue will continue to run after the fade is complete.

Preview. This button provides quick access and a visual reference to the live fade preview setting.

Relative Fades

By default, Fade cues are Absolute. This means that any parameters that you adjust with a Fade cue will arrive at their final levels regardless of their status before the Fade cue runs. If you use a Fade cue to set the scale of a target Video cue to 2, then the scale of that Video cue will end up at 2 after running the Fade no matter where that level was set to begin with.

However, using the pop-up menu on the left side of the Levels tab or Geometry tab, you can set a Fade cue to be a relative fade. Instead of setting levels to a specific value, relative fades either add or subtract a given amount or multiply or divide a given amount from, to, or by the active parameters, so the starting point of those parameters very much matters. When set to relative, the cue’s icon changes to the relative form.

In this screen shot, the Fade cue has its scale set to 0.9 which has the effect of reducing the size of the target to 90% of its current size. If you ran the Fade cue three times, the cumulative result would be reducing the size of the target cue to 72.9% of its original size, since each time the Fade cue runs, it causes a 90% reduction of the then-current size.

Relative opacity changes are similarly multiplicative; a relative Fade cue set to an opacity of 90% will reduce the opacity of its target by 10% of its then-current opacity.

Relative translation and rotation changes are additive, so a relative Fade cue set to an X-axis translation of 100 will add 100 pixels to the X-axis translation of its target each time it runs.

Relative fades which adjust 3D rotation or video effects can have results which are difficult to predict, and so this manual will refrain from making blanket statements about them.

In QLab 4, using absolute Fade cues on a parameter that had previously been adjusted by relative Fade cues could have unpredictable results. In QLab 5, however, absolute fades supersede relative ones. In QLab 5, an absolute fade is absolutely more absolute.

Reverting Fades

QLab has a sort of special-case undo command that applies only to Fade cues, called Revert Fade Action. You can find this command under the Tools menu when a Fade cue is selected, or you can use the keyboard shortcut ⇧⌘R.

When Revert Fade Action is invoked on a Fade cue after that Fade cue has been run, QLab reverts the levels of that Fade cue’s target to whatever they were before the Fade ran except for levels which have been otherwise changed. That is to say, the only adjustments that are reverted are the ones that the selected Fade cue caused.

Broken Fade Cues

Fade cues can become broken for the following reasons:

Missing cue target

Assign a target cue to this cue.

No parameters set to fade

Set this cue to adjust at least one parameter. You can enable or disable an audio parameter by clicking in it; active controls will be highlighted in yellow. You can enable or disable a video parameter by checking or unchecking the box next to it.

Missing cue audio effect

Either install the missing audio effect and restart QLab, or remove the missing effect from the Audio FX tab of the inspector of the target cue.

License required

An audio or video license is required to fade playback rate, fade audio effects, fade patches, or use Timecode triggers. A video license is required to fade video geometry or video effects. Install the appropriate type of license or adjust the cue to avoid using licensed features to clear this warning.