1.Spline Extensions #

Thank you for testing Spline Extensions!

This asset is developed for Unity 2022.3.21+. Using it with older versions runs the risk of script compile errors. Unity 6.x does not affect this asset and it fully compatible.

Access to the preview package is available by verifying your Spline Mesher, Spline Spawner or River Modeler license on Discord.

Discord Server

After verifying your license, the #spline-extensions-preview channel becomes available. See the pinned message for a download link.

What is Spline Extensions?

This asset provides a swiss-army knife of Spline utilities, enhancing the way you can work with Splines. Crafted for professionals, easy to use by anyone.

Features many components that create splines, that can be used with other scripts/components that use splines.

It is an excellent companion to spline-based tools such as Spline Mesher, Spline Spawner, River Modeler or MicroVerse Splines. And any of the native Unity spline components.

All tools are non-destructive and function in realtime. Optimized for performance using Burst & Jobs.

🛠 Included Components:

Attach Transform To SplinePosition anything on a Spline, at a specific distance, percentage or snapped to the nearest transform.
Create Spline From ObjectsA no-code solution for creating dynamic Splines, by assigning Transforms to trace.
Grid Snapped SplineCreates a Spline that is snapped to a virtual grid.
Spline Caps Attaches and aligns a prefab to the start- or end of a Spline
Spline Spiral For artistic purposes, a spiraling Spline can be created, with ample controls
Spline Looping For use with mesh generation. Creates a procedural looping.
Spline Line RendererCopies a Spline curve onto a traditional Line Renderer component
Spline RectangleWith rounded corners and specified width/length
Spline CircleAdjustable diameter and knot rotation
Spline SmoothedCreates a smoothed version of an input Spline
Spline Particle EmitterCreate a Spline-surface for a Particle System to spawn on
Spline EventsExposes standard Unity events in a UI for when a Spline gets added, removed or is changed. Makes scriptless behaviour, based on Spline editing, possible.
Spline ColliderAdds a Box or Tube collider to a Spline with trigger/collision callbacks, support native physics and nav-meshes.

🚀 Advanced Components:

▪️ Create Parallel Splines

Creates a new set of Splines that run parallel to another one. Useful for spawning side objects along roads or rivers.

▪️ Spline Grid

Creates rows & columns of new splines within an Rectangle or a Spline’s area.

▪️ Spline Curbs

Creates new splines based on the turning strength of another Spline, and whether the turn curves inward or outward. Excellent for generating guard rails.

▪️ Distorted Spline

Use layers of configurable noise to create a distorted Spline that follows a source spline. Used for meandering rivers or roads.

▪️ Rounded Spline

Copies a Spline, but creates a rounded curve around each knot. Useful for creating pipelines.

▪️ Spline Audio Emitter

Makes an Audio Source follow the camera, whilst restricting it to the Spline’s edge and/or volume. Crucial for some localized soundscapes!

▪️ Spline Segments

Allows the creation of new splines, onto an existing one. Using two transforms to specify the start/end, or a distance value.

▪️ Spline Wires

Creates wire-shaped splines between Spline knots, with loops and sagging.

The demo scene showcases all of these components

⭐️ Editor tools

• Includes an extensive Spline Visualizer component, which displays Spline data as Gizmos in the scene view. Extremely useful for development or debugging spline-based code.

• The Paint Spline scene-view tool makes creating new splines a breeze!

⚙️ Adds new context menu functions to your Spline Containers:

Center Pivot
Remove Twists
Reverse Flow
Flatten Knots (X/Y/Z)
Flip (X/Y/Z)
Apply Transform

🔎 New C# extension functions:

Spline.Contains(Vector3 worldPosition)
SplineContainer.Flatten()
SplineContainer.Flip()
SplineContainer.RemoveTwists()
SplineContainer.ApplyTransform()
SplineContainer.RemoveInvalidSplines()
SplineContainer.CalculateTotalBounds()
Spline.CalculateBounds()
BezierKnot.IsLinear()

(These functions also have an Editor variant, for custom tools, that supports undo/redo operations)

✅ Supports

• Runtime functionality

• Undo/redo operations

🚧 Limitations:

• Not designed for 2D level design

Development timeline

This package is developed alongside of other spline tools, where fixes are done as issues arise, and improvements are made as they appear needed.

The majority of the work ahead lies in improving this documentation and creating solid example materials. Many of the included components have wide creative and practical uses, which needs to be demonstrated properly.

Until that time, eligible users will have free access. The asset will likely be priced at $35, with a permanent discount for Spline Mesher and Spline Spawner users.