How the Chain Works

The chain is the core of Lightbridge. It’s the list of sources and effects that produce your visual output, and the order matters.

Tip

For the full architectural picture — the flat accumulator, the render loop, the feedback pass, per-source effects, and transforms — see the Chain Model concept. This guide is the hands-on workflow.

Sources and effects

• Sources generate visuals — patterns, fractals, textures, video feeds.
• Effects transform whatever is above them in the chain — blur, bloom, colour shifts, distortions.
• Instruments add a source together with its performance buttons. Open Instruments from the chain palette, choose one, then confirm adding its buttons to the current set.

When you add a source, it composites on top of everything already in the chain’s accumulator. When you add an effect, it processes the entire accumulated image up to that point.

An instrument is a bigger gesture than dropping a single source: it inserts one source node and appends set-scoped action buttons that are already wired to it. Use it when you want a playable setup, such as a Particle Playground beat-burst row, instead of a blank source to patch from scratch.

Why order matters

The chain renders top to bottom. Each source composites onto what’s already there, and each effect transforms the current composite.

Consider two different orderings:

Voronoi → Plasma → Bloom

Bloom applies to both Voronoi and Plasma — the whole image glows.

Voronoi → Bloom → Plasma

Bloom only applies to Voronoi. Plasma renders on top of the glowing Voronoi, unaffected by bloom.

To reorder: drag nodes up or down in the chain editor.

Blending with opacity

Each source has an opacity parameter that controls how much of it ends up in the final pixel. At 100%, the source fully covers what’s underneath (when combined with the over blend mode). At 50%, it blends half-and-half. Select a source and adjust the opacity slider in the parameter panel.

Blend modes

Beyond simple opacity, each source has a blend mode that controls how its pixels combine with the current accumulator. Lightbridge ships nine blend modes:

Mode	Feel
over	Default — source replaces destination
add	Aggressive brighten (glows, lasers)
multiply	Darkens / tints
screen	Softer brighten (light leaks, fog)
overlay	Contrast boost
softlight	Gentle contrast lift
dodge	Strongest brighten
difference	Colour-inverting, high contrast
exclusion	Softer difference

To change a source’s blend mode, select it in the chain and use the blend mode selector in the parameter panel header. See the Blend Modes reference for formulas and typical uses.

Effects apply to the composite

A key concept: effects don’t target individual sources. They transform the entire accumulated image at the point where they sit in the chain. If you want an effect on only one source, place it directly after that source and before any others — or use per-source effects (below).

Every effect also has a mix parameter in [0, 1]. At mix = 0 the effect is bypassed; at mix = 1 it runs at full strength. Mid-values crossfade between dry and wet, which is useful for dialling in an effect.

Selecting and moving nodes

Click a chain node to select it. To select more than one:

• Shift+click extends the selection to a contiguous range.
• Cmd/Ctrl+click toggles individual nodes in and out of the selection.
• Marquee (rubber-band) select — click-drag on the chain background (or between cards) to sweep out a selection rectangle. Holding Shift/Cmd/Ctrl while marquee-dragging adds to the existing selection instead of replacing it; the cursor switches to a copy glyph to confirm.

Once you have a multi-selection you can drag the whole group as one — the cards lift together and originals ghost in place until you drop.

Grouping nodes

When a chain gets long, you can bundle related nodes into a group — a node that contains its own mini-chain. Groups keep your top level tidy and, more importantly, let you scope effects: an effect placed inside a group only transforms the nodes inside that group, not the rest of the chain.

To create a group: select two or more sibling nodes in the chain (see above) and press Cmd+G (or right-click → Group Selected). They collapse into a single group card that behaves like a source — it has opacity, a blend mode, and composites into whatever’s above it.

To edit a group: double-click the group card to drill into it. The chain header swaps to a breadcrumb trail showing where you are — click any segment to jump back, or press Escape to go up one level.

To ungroup: right-click the group → Ungroup. The children move back to the parent level; the group itself is deleted. (Delete removes the group and its children — use Ungroup when you want to keep them.)

Common uses:

• Scoped bloom / blur — group a few sources, drop bloom inside, and only those sources glow.
• Reusable effect stack — a group containing only effects (an “FX GROUP”) applies its effects to the parent accumulator at that point in the chain.
• Organising a complex build — nest by section (background / midground / foreground) and drill in only when you need to tweak.

Groups can nest up to four levels deep.

Per-source effects

To apply an effect to just one source without affecting anything else in the chain, use per-source effects. Right-click the source in the chain editor and use the Source Effects option — the effect will apply to that source’s image before it composites onto the accumulator, so nothing else sees it.

Per-source effects are the right tool when:

• You want to blur or distort one layer without blurring the rest
• You want the effect to “follow” the source wherever you move it in the chain
• You want to stack chain effects on top of the already-processed source

Related

• The Chain Model — the architectural view: flat accumulator, render order, transforms, feedback.
• Blend Modes reference — all nine modes with formulas and typical uses.
• Performing Live — how you wield the chain during a gig.