Map an Effect to an LED Strip

Map effects to individually addressable LED pixels.

Goal

Create a position map and apply effects to:

• LED strips
• LED matrices/panels
• Custom pixel arrangements

Time: 20-25 minutes

What is position mapping?

Position mapping treats a group of LEDs as a canvas. Instead of controlling fixtures individually, you render effects to a 2D (or 3D) space, and each pixel receives its color based on position.

Step 1: Create a position map

1. Open the Mappings panel (via Window > Add panel > Mappings, or switch to the Position Maps workspace)
2. Click + to create a new position map
3. Name it (e.g., "LED Wall")
4. Set dimensions:
   • Width: Number of pixels horizontally
   • Height: Number of pixels vertically

For a single LED strip of 60 pixels:

• Width: 60
• Height: 1

For a 16x16 matrix:

• Width: 16
• Height: 16

Step 2: Map pixels to DMX

Each pixel needs a DMX address:

1. Open the Position Map Editor
2. Select your position map
3. Click Auto Address for sequential addressing
4. Or manually assign addresses by clicking pixels

Addressing modes

• Sequential - Pixels addressed in order
• Snake - Alternating direction each row (common for zigzag LED strips)
• Custom - Manual assignment for irregular layouts

Universe spanning

Large position maps span multiple universes:

• Universe 1: Pixels 1-170 (at 3 channels each)
• Universe 2: Pixels 171-340
• And so on...

Step 3: Position the position map

For accurate preview visualization:

1. In the Position Map settings, set:

   • Position - Where the map appears in 3D space
   • Scale - Physical size
   • Rotation - Orientation

2. Or drag in the Preview panel with the positioning tool

Step 4: Create a pixel effect

Effects for position maps use spatial nodes:

1. Create a new layer for your position map

2. In the Node Editor, add:

   • Input > Pixel Position - Provides normalized coordinates (0-1)
   • Color > HSL to RGB - Converts a position value to color
   • Color > Combine Color - Assembles RGB channels into a color
   • Output > Output

3. Connect: Pixel Position X output → HSL to RGB Hue → R/G/B to Combine Color → Output

Understanding Pixel Position coordinates

Pixel Position provides a normalized position for each pixel:

• X: 0 at left edge, 1 at right edge
• Y: 0 at top, 1 at bottom

Use these to create position-based effects.

Step 5: Animate the effect

Add movement:

1. Add an Input > Time node
2. Add the time value to the X coordinate:
   • Pixel Position X output
   • Time + X → Fractional Part → HSL to RGB → Combine Color → Output

This creates a moving rainbow across your pixels.

Step 6: Apply different patterns

Radial gradient

1. Use Spatial > Exponential Falloff or Spatial > Linear Falloff from center
2. Map distance to color

Waves

1. Use Wave > Sine with Pixel Position as input
2. Combine horizontal and vertical for interference patterns

Shapes

1. Use SDF Primitives for spheres, boxes, etc.
2. SDF Primitives > Sphere SDF with Pixel Position creates circular patterns

Step 7: Assign to fixtures

Connect the position map to your output:

1. In Position Map Settings, assign the Output Universe(s)
2. Ensure Art-Net is configured for those universes
3. Test output to verify mapping

Working with multiple position maps

For complex setups:

1. Create separate position maps for each element
2. Each can have independent effects
3. Or use the same effect with different position transformations

Example setup

• "Back Wall" - 100x50 matrix
• "Floor Strips" - 8 strips of 60 pixels each
• "Ceiling Ring" - 200 pixels in a circle

Position map tips

Performance

Large position maps need more processing:

• Reduce effect complexity for many pixels
• Lower preview quality if needed
• Use efficient node graphs

Color accuracy

Different LED types vary:

• Adjust gamma in output settings
• Use color calibration if available
• Test with actual hardware

Troubleshooting mapping

If pixels are out of order:

• Check your addressing mode (sequential vs. snake)
• Verify start address
• Check universe assignments

Next steps

• Explore spatial nodes
• Learn about SDF effects
• Set up Art-Net output