DMX and Art-Net (Lighting)
Controlling physical lighting fixtures and LEDs from TouchDesigner using standard protocols.
DMX
DMX (Digital Multiplex) is the standard digital communication protocol used to control stage lighting and effects.
- DMX Out CHOP: Use this to send data to USB-to-DMX interfaces (like Enttec).
- DMX In CHOP: Use this to receive data from a physical lighting console to control your TD scene.
Art-Net / sACN
Sending DMX data over Ethernet (UDP). This is the preferred method for high-count pixel systems (e.g., thousands of LEDs).
- Art-Net: Widely used, but can be less efficient than sACN for very large installations due to its broadcast nature. In TD, set the ‘Local Address’ and the target ‘Network Address’.
- sACN: Uses multicast, making it more scalable for complex network environments.
DMX via POPs (TD 2025+)
TouchDesigner 2025 added a GPU-native DMX path that complements the CHOP approach above.
- DMX Fixture POP: Define a single fixture’s channel profile (pan, tilt, color, dimmer, strobe, etc.) as a POP. Combine multiple Fixture POPs for a full rig.
- DMX Out POP: Connects to one or more DMX Fixture POPs, merges their universes, and transmits to DMX USB (FTDI), Art-Net, sACN, or KiNET hardware in one node.
When to use POPs vs CHOPs:
| Scenario | Recommended path |
|---|---|
| Simple rig, a few fixtures | DMX Out CHOP - less setup, easier to debug |
| Large LED array / pixel-mapped installation | DMX Out POP - stays on GPU, scales to thousands of points |
| Generative lighting driven by POP simulation | DMX Out POP - attributes flow directly from POP chain without CPU round-trip |
Pro-Tips
- Universe Management: One DMX Universe has 512 channels. If you are controlling RGB LEDs, that’s only 170 pixels per universe (512 / 3).
- Refresh Rate: Most lighting fixtures expect a 44Hz or 40Hz refresh rate. Ensure your TD network is optimized to maintain this speed.
- Visualization: Always build a 3D visualization of your lights in TD (using Instancing and the Geometry COMP) before going to the physical site.
📚 Learning Path · Stage 7 - Connectivity & Shaders · step 39 of 44
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