<sk-field-constraint>

← prev index next →

Drives one property of a node from a field's weight at that node's position — the way to make position in space control a value like scale or opacity.

JavaScript API: FieldConstraint

Remarks

This is the field-reading member of the Constraint family: like every constraint it drives its constrained target by recomputing from live scene state each frame — here it samples a SpatialField at the target's world position, turns the field weight into a scalar, and writes it to one target property. It is a single-node, CPU-evaluated constraint, distinct from its GPU per-clone counterpart.

Key attributes. field names the field to sample, by #id — any CPU-evaluable field such as the SpatialField shapes (the GPU-only sk-color-source-field has no effect here). target-property selects which property the weight writes (e.g. s for uniform scale, opacity); the raw 0–1 weight can be remapped into the value range that property needs. One field can drive several field-constraints at once by sharing its #id.

Related. Consumes a SpatialField — the same field a material or tonemap can also read, so one field can tint a surface and drive a property together. Its GPU-parallel sibling is the sk-simple-point-constraint, which applies a field weight to every clone of a Cloner at once rather than to a single node.

Serve these docs to run the live example. WebGPU needs a secure context — open this page via grunt serve rather than double-clicking the file. The Markup tab works from disk.

Attributes

AttributeTypeDefaultDescription
fieldanimatable <id-ref> — The field that provides weight values. reference by id
target-property <property-name> — The target property on the target animatable that will receive the mapped value.
priority <number> — Priority for effect ordering.
composite <constraint-composite> ("replace" | "add" | "accumulate") — Composite operation for this modifier.

↑ Documentation home · ← All elements