DMX Output & Mapping

FXCanvas can drive real lighting rigs from your render canvas. Colors from your visuals are sampled, transformed, and sent out over Art-Net or sACN to fixtures like LED bars, moving heads, and pixel tape, using industry standard GDTF fixture profiles.

This guide walks through the whole pipeline: importing fixtures, patching them, grouping them, laying them out in 2D, defining how the canvas maps onto them, and finally configuring network output.

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Concepts at a Glance

Before jumping in, it helps to understand the main building blocks.

Concept	What it is
Rig	A saved collection of fixtures, groups, layout positions, maps, and regions. Rigs live outside shows so you can reuse them.
Fixture Type	A GDTF file describing a physical fixture model (channels, modes, emitters).
Fixture Instance	A single patched fixture in your rig (one row in the patch).
Group	A named set of fixture instances. MVR-imported or user-created.
Layout	The 2D positions of fixture instances on a plan view.
DMX Map	A named collection of layers that defines how the canvas drives fixtures.
Mapping Layer	A single rule inside a map: one group, one strategy, one transform.
Input Region	A rectangular area of the render canvas used as the source for a layer.
Output	Art-Net or sACN transmission to one or more universes.

All of this lives inside the DMX Manager window, which is organized as seven tabs.

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The DMX Manager Window

Open it from Tools → DMX Manager. The tabs run left to right in the order you would typically use them:

Tab	Purpose
Rigs	Create, load, save, delete, and set the default startup rig. Import MVR files.
Fixtures	Manage fixture types in the rig. Import GDTF, browse the online fixture library.
Patch	Assign fixtures to universes and DMX addresses. Grid or Table view.
Groups	View MVR groups and create custom groups for targeting in maps.
Mapping	Position fixtures, define maps and layers, and edit input regions.
Output	Configure Art-Net or sACN transmission.
Monitor	Watch live DMX channel values being sent out.

If the rig has unsaved changes, the Rigs tab shows an asterisk (Rigs *) and closing the window prompts you to save, discard, or cancel.

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Typical Workflow

A first-time setup usually goes like this:

1. Create or load a rig on the Rigs tab.
2. Add fixture types on the Fixtures tab by importing GDTF files, importing an MVR, or downloading from the online library.
3. Patch fixtures on the Patch tab to specific universes and addresses.
4. Organize into groups on the Groups tab (optional but recommended).
5. Arrange fixtures in 2D on the Mapping tab in Layout mode.
6. Create a DMX map with layers on the Mapping tab in Output mode.
7. Optionally define input regions on the Mapping tab in Input mode.
8. Configure output on the Output tab and enable transmission.
9. Verify with the Monitor tab and physical fixtures.

The rest of this page covers each tab in detail.

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Rigs

A rig is everything about your physical lighting setup. Rigs are saved in ~/Documents/FXCanvas/Rigs/[RigName]/ with a rig.json plus any imported MVR and GDTF files.

What a rig contains

• Fixture types (GDTF data)
• Fixture instances (patch, positions)
• MVR groups (read-only) and custom groups
• DMX maps and mapping layers
• Input regions
• Layout positions

Creating and managing rigs

Action	How
New rig	Click New Rig, enter a name
Load	Select a rig in the list and click Load
Save	Click Save (only enabled when dirty)
Rename	Right-click or use the action menu in the rig row
Delete	Right-click or use the action menu, confirm in the modal
Set as default	Check the default box so the rig loads on next startup

Importing an MVR

MVR (My Virtual Rig) is the industry-standard file that most lighting design software exports. FXCanvas can import an MVR and create everything it describes in a single step.

1. On the Rigs tab, click Import MVR.
2. Select the .mvr file.
3. FXCanvas extracts embedded GDTF files, creates fixture types and instances, sets patch addresses, reads positions, and creates MVR groups.

Progress is shown in an overlay. Import runs on a background thread so the UI stays responsive.

tip

An MVR is by far the fastest way to bootstrap a rig. Ask your lighting designer for one instead of manually patching fixtures.

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Fixtures

The Fixtures tab manages the fixture types available in the rig. A fixture type is a GDTF file; fixture instances are created later on the Patch tab.

The tab has two view modes, toggled at the top:

• Rig Fixtures — fixture types already loaded into the current rig
• Fixture Library — search and download from the online GDTF Share library

Rig Fixtures view

Two-pane layout:

• Left: list of fixture types (manufacturer, model, count of instances)
• Right: details for the selected type, including modes, channel counts, emitters, and physical geometry

From here you can see exactly which modes are available on each fixture and what the DMX footprint of each mode is.

Importing a single GDTF

Click Import GDTF above the list, select a .gdtf file, and it gets parsed and added to the rig. The file is copied into the rig's GDTF/ folder so the rig stays self-contained.

Fixture Library (online GDTF Share)

Switch to Fixture Library to search the GDTF Share database directly from within FXCanvas.

Features:

• Search by manufacturer or model
• Filter sidebar for manufacturers and channel counts
• Results table with pagination
• Details pane showing full GDTF preview (channels, modes, emitters) once downloaded
• Add to Rig dialog — pick a DMX mode, set quantity, and optionally specify a start address (leave blank for auto)

The preview is cached across selections so flipping between fixtures is fast.

Emitters

Multi-color fixtures (RGBW, RGBA, etc.) are modeled as one or more emitters per fixture. Each emitter carries its own color channels (Red, Green, Blue, White, Amber, Lime, UV, Cyan, Magenta, Yellow, Warm White, Cool White). FXCanvas renders each emitter individually in the mapping viewport so you get accurate multi-emitter behavior out of the box.

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Patch

The Patch tab assigns fixture instances to universes and DMX addresses. Two display modes cover different workflows:

• Grid — visual universe map, click-to-patch
• Table — sortable list with inline editing

Toggle between them at the top of the tab.

Grid view

Three panels:

• Left: Fixture Inventory — unpatched fixtures waiting to be placed
• Center: Patch Grid — the selected universe, 512 cells showing how channels are allocated
• Right: Inspector — details for the currently selected fixture

Workflow:

1. Pick a universe from the selector.
2. Click a fixture in the inventory to select it.
3. Click a cell in the grid to patch it at that address.
4. Drag fixtures on the grid to move them.

Overlaps and out-of-range placements are highlighted.

Table view

A flat table of all patched fixtures with columns for FID, Name, Type, Mode, Address (universe.address), and Channels. Click headers to sort. Use the search box to filter by any visible column. Double-click a row to open the Edit Fixture dialog, where you can change name, type, mode, universe, and start address.

Importing MVR

The Patch tab also exposes an Import MVR button, equivalent to the one on the Rigs tab — handy if you're already in the patch workflow.

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Groups

Groups are named sets of fixtures. They make the Mapping tab much more powerful because layers target groups rather than individual fixtures.

Two sources:

• MVR Groups — read-only, imported from MVR Position nodes
• Custom Groups — created and edited inside FXCanvas

Creating a custom group

1. Click New Group.
2. Enter a name.
3. Move fixtures from Available to Selected using the arrow buttons.
4. Click Save.

Selection supports Ctrl+click and Shift+click multi-select. The Add All dropdown lets you bulk-add by fixture type or by copying from an existing group.

Using groups in maps

Custom groups appear alongside MVR groups in the layer creation dialog on the Mapping tab. A special "All Fixtures" pseudo-group is always available.

Deleting a group used by a DMX map triggers a warning so you don't break existing mappings.

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Mapping

The Mapping tab is where the canvas meets the fixtures. It has three modes, switched with buttons at the top:

• Layout — position fixtures in 2D
• Output — define how the canvas drives fixtures
• Input — define canvas regions used as sources

Layout mode

A 2D floor plan view of your rig.

• Pan with middle-mouse drag
• Zoom with the scroll wheel
• Select by clicking fixtures; Ctrl+click multi-selects; drag a box for area-select
• Move with the gizmo's X, Y, or center handle
• Undo / Redo for all layout edits

MVR imports bring real-world positions in meters. Without an MVR, you can arrange fixtures manually to match your venue. Layout is saved with the rig.

Output mode

The left column has three sections:

1. DMX Maps — list of maps; radio buttons pick the active one, selection picks the one you're editing
2. Layers — ordered list of layers inside the selected map (drag to reorder, topmost wins)
3. Layer Settings — details for the selected layer

The right side is the viewport showing fixtures with live color preview when an active map is set.

Creating a map

A DMX map is a named container for layers. Cues can bind to a map by name, so different cues can drive different mappings.

1. Click Add Map.
2. Enter a name and pick an initial group and strategy.
3. The map appears in the list; click the radio button to make it active.

Only the active map affects DMX output. You can edit a non-active map without disturbing the running show.

Creating a layer

Each layer inside a map has:

• Group — which fixtures it targets
• Strategy — how the canvas is applied
• Transform — offset, scale
• Options — mirror X, mirror Y, tile vs clamp
• Projection plane — XZ (top view), XY (front view), or YZ (side)
• Input region — which canvas area to sample (empty means the full canvas)
• Scale mode — how the region content fits inside the layer
• Active — on/off toggle

Layers are evaluated in order. Use ordering to decide which layer wins on fixtures that belong to multiple groups.

Mapping strategies

Strategy	What it does	Use when
Across Group	Canvas stretched across the 2D positions of fixtures in the group	You want a gradient or wave to flow across the rig
Per Fixture Type	Full canvas rendered once per fixture type, shared transform	A fixture type renders the same regardless of position
Per Fixture	Full canvas rendered per individual fixture, unique per-fixture transforms	You need each fixture to sample a different part of the canvas

For Per Fixture, you can select individual fixtures and give them their own transform overrides.

Canvas overlay and transform

When Output mode has an active layer, a rectangular overlay shows the area of the canvas that the layer is sampling. Drag the overlay to move it, or drag corners to scale. Direct numeric editing is also available in the Layer Settings.

Reset returns a layer transform to defaults.

Input mode

Input mode lets you define named rectangular Input Regions on the render canvas. A layer can reference a region to sample only that part of the canvas instead of the whole thing.

Left column:

• Input Regions list with Add / Delete
• Region Settings for the selected region: name, position, size (all normalized 0-1)

Right side:

• A preview of the render canvas with draggable / resizable region rectangles drawn on top

Why use regions:

• Split the canvas between different fixture groups (e.g. left half for the front truss, right half for the back truss)
• Isolate a specific visual element, like a scrolling text region, to drive only one fixture group
• Reuse the same canvas for multiple distinct looks

Regions are independent of maps — any layer in any map can reference any region.

tip

If a layer's Input Region is left empty, it samples the full canvas. Use regions only when you need to partition the canvas.

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Output

The Output tab configures the actual network transmission of DMX data.

Sections:

Section	What it controls
Enable DMX Output	Master on/off
Auto-Configure	Automatically create universes from patched MVR fixtures
Protocol	Art-Net or sACN (E1.31)
Network	Network interface selection
Transmission Mode	Broadcast or Unicast (with address for unicast)
sACN Settings	Source priority (sACN only)
Universes	List of active universes with enable/disable
GrandMA3 Guidance	Ready-to-use values for configuring Art-Net Input on grandMA3
Status	Transmission state, frame rate, packet count

Universe management

Universes can be auto-generated from the patch, or added manually. Each universe has a port address computed as:

Port Address = (Net × 256) + (SubNet × 16) + Universe

Click Add Universe to add one manually; specify Net (0-127), SubNet (0-15), and Universe (0-15). Delete with confirmation.

Auto-configure from patch

With Auto-Configure enabled, any universe your patched fixtures live on is added automatically. This is the easy path: patch your fixtures, turn on auto-configure, and FXCanvas handles the universe list for you.

Protocol choice

Protocol	When to use
Art-Net	Most common, works with almost everything, UDP port 6454
sACN (E1.31)	Preferred for larger professional systems, supports priorities and unicast natively

note

FXCanvas can only transmit one protocol at a time. Select whichever matches your downstream equipment.

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Monitor

The Monitor tab shows live output values on the wire.

Features:

• Universe selector with fixture count for each universe
• Channel grid (32×16) where cells are tinted by their color role (Red, Green, Blue, White, etc.)
• Fixture boundaries highlighted so you can see where each fixture lives
• Tooltips showing channel number, value, percent, and the fixture and channel function

Use the Monitor tab to verify that your maps and layers are producing the expected output before trusting the rig.

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Driving Maps from Cues

Maps can be bound to cues by name. When a cue fires, its bound map becomes active.

• In the Cues panel, set the DMX Map for a cue to any existing map name.
• If a cue references a map that doesn't exist, Mapping tab's map list shows a Missing Maps section with a Create button so you can resolve it in place.

This lets you change the entire lighting behavior per cue without touching the patch or the fixtures.

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Troubleshooting

Fixtures don't appear in the Layout viewport

• Make sure the rig has fixture instances (Patch tab)
• Click Fit All in the viewport toolbar to recenter
• Check the group filter — switch to "All Fixtures" to rule it out

No color reaches the fixtures

• Is a DMX Map active (radio button on the Maps list)?
• Is the map's layer enabled?
• Is DMX Output enabled on the Output tab?
• Is the fixture patched to a universe that appears in the Output universe list?
• Does the fixture's GDTF mode actually have color channels? (Check in the Fixtures tab.)

Art-Net or sACN receiver sees nothing

• Verify the Output tab shows Transmitting and a nonzero frame rate
• Confirm protocol, universe, and network interface match the receiver
• For Art-Net, check that UDP port 6454 is not blocked by a firewall
• Try switching to Unicast if broadcast isn't getting through

Wrong fixture gets the wrong color

• Open the Monitor tab and watch the channels live
• Check the layer ordering in the map — a later layer might be overwriting
• Verify the layer's group targets the expected fixtures
• For Per Fixture strategy, check per-fixture transform overrides

MVR imported but fixtures look stacked on top of each other

• The MVR may use 2D-only layouts, which place all fixtures at the origin
• Switch to Layout mode and arrange them manually; save the rig

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Tips and Best Practices

Start with an MVR

An MVR import gets you 90% of the way: fixture types, instances, patch addresses, positions, and groups all come for free.

Keep rigs reusable

Name rigs by venue or setup (MainStage, RehearsalRoom). Rigs live outside shows, so you can reuse the same rig across multiple shows.

Group aggressively

Well-named groups make the Mapping tab dramatically easier to work with. Group by physical position (front truss, back truss) or by role (pixel tape, wash, moving heads).

Use input regions sparingly

Most setups only need the full canvas. Only reach for input regions when you genuinely need to partition the canvas among different groups.

Verify before the show

Turn on the Monitor tab and walk through your cues with the rig powered up. Catching a missing patch or a dead universe in soundcheck is a lot easier than during the opener.

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Related Topics

• DMX Input (palette control) — using Art-Net to control FXCanvas palettes from a console
• Shows and Cues — bind maps to cues for per-scene lighting behavior
• Palettes — the color palettes whose colors end up on your fixtures
• Outputs — NDI / Spout / Syphon / Display outputs for video