Node Reference
Selection Nodes
Nodes for targeting fixtures and extracting spatial attributes from fixture arrangements.
Selection nodes define which fixtures are targeted and extract spatial attributes from fixture arrangements.
| Field | Value |
|---|
| Type ID | select |
| Category | Selection |
| Description | Resolves a tag expression into a set of fixtures with 3D positions. |
None.
| Name | Type | Default | Description |
|---|
tag_expression | string | "all" | Boolean tag expression to match fixtures |
spatial_reference | string | "global" | "global" or "group_local" |
all -- matches every fixture- Simple tags:
front, left, circular, blinder
- Capability tokens:
has_color, has_movement, has_strobe
- Operators:
& (AND), | (OR), ^ (XOR), ~ (NOT), > (fallback)
- Parentheses for grouping:
(left | right) & has_color
- Examples:
front, left & has_color, circular & ~blinder
spatial_reference="global": All matched fixtures returned in a single Selection with global coordinates.spatial_reference="group_local": Separate Selection per fixture group, with coordinates relative to each group's local frame.
| Field | Value |
|---|
| Type ID | get_attribute |
| Category | Selection |
| Description | Extracts a spatial or ordering attribute from each fixture in a Selection as a scalar Signal. |
| Port | Type | Required |
|---|
selection | Selection | Yes |
| Port | Type |
|---|
out | Signal (N=total items, T=1, C=1) |
| Name | Type | Default | Description |
|---|
attribute | string | -- | The attribute to extract (see table below) |
| Attribute | Description | Range |
|---|
index | Integer order within the selection | 0, 1, 2, ... |
normalized_index | Order normalized to range | 0.0 - 1.0 |
pos_x | Absolute global X position | meters |
pos_y | Absolute global Y position | meters |
pos_z | Absolute global Z position | meters |
rel_x | X position relative to selection bounding box | 0.0 - 1.0 |
rel_y | Y position relative to selection bounding box | 0.0 - 1.0 |
rel_z | Z position relative to selection bounding box | 0.0 - 1.0 |
rel_major_span | Position along axis with largest physical range | 0.0 - 1.0 |
rel_major_count | Position along axis with most distinct positions | 0.0 - 1.0 |
circle_radius | Distance from selection center | meters |
angular_position | Angle on fitted circle (PCA + RANSAC) | 0.0 - 1.0 |
angular_index | Index-based angular position (equal spacing) | 0.0 - 1.0 |
- For angular attributes, circle fitting is performed using PCA plane projection and RANSAC. This works for 3D arrangements, not just planar layouts.
rel_major_span and rel_major_count are useful when the fixture arrangement's primary axis is not known ahead of time.
| Field | Value |
|---|
| Type ID | random_select_mask |
| Category | Selection |
| Description | Randomly selects N items from a Selection based on a trigger signal. Changes selection when trigger value changes. |
| Port | Type | Required |
|---|
selection | Selection | Yes |
trigger | Signal | Yes |
count | Signal | No (number of items to select) |
| Port | Type |
|---|
out | Signal (N=items, T=trigger.T, C=1, values 0 or 1) |
| Name | Type | Default | Description |
|---|
avoid_repeat | int | 1 | If 1, avoids selecting the same items on consecutive triggers |
- Selection is deterministic (hash-based seeding) for reproducibility across evaluations.
- Trigger changes (e.g., beat pulses crossing a threshold) cause re-selection of which items are active.
- Output is a binary mask: 1.0 for selected fixtures, 0.0 for unselected.