Spatial attachments

Coordinates select particles on the current world-space shape, not a target destination. Radius zero selects the nearest particle; positive radius selects all inside a sphere. Empty or overlapping regions fail. Disabled attachments still reserve their particles until destroyed. Changing host or enabling captures current offsets without a jump.

Example#

anchor = soft.create_attachment(0, 0, 3.5, 0.3);
if (!is_undefined(anchor)) {
    anchor.set_body(support);
    // anchor.set_enabled(false);
    // anchor.destroy();
}

Usage and limits#

World/Static/Kinematic targets prescribe positions. Dynamic hosts use compliant two-way attachments with opposite impulses and host rotation. This is not a rigid weld. Only the Soft Body–host collision pair is suppressed; other collisions remain. Dynamic attachments subdivide the world step to at most 1/480 s, capped at roughly 64 segments; measure scene-wide cost.

A destroyed host disables its attachments but preserves selections for reassignment. Soft Body destruction removes them. Existing cloth grid pins retain their original one-way behavior and cannot overwrite particles reserved by spatial attachments. Release the region through the attachment itself. Getters report current position, point count, host and enabled state.

API reference#

Public function and method signatures. Call methods on the returned instance; parameters with defaults are optional.

Related guides#

• Migrating existing code›
• Choosing a Soft Body›
• Soft sphere›
• Volumetric soft box›
• Closed model import›
• Cloth model and named anchors›
• Separate visual mesh›
• Local force and impulse›
• Wind›
• Carrying Soft Bodies›

Verified operation contracts#

These contracts distinguish units, return values, errors and lifetime according to the current implementation. Check results: false, 0 and undefined can mean different things for different methods.