4.Scripting #

Familiarity with C# and OOP programming is assumed. Support cannot be extended to coding help. Some specific functionality and use cases really need to be handled on a project-specific basis with some creative thinking.

If you are using an assembly definition, ensure you add a reference to the sc.splines.mesher.runtime assembly, otherwise you won’t be able to access the namespace and classes.

Whenever using the API, ensure you add using sc.splines.mesher.runtime; to include the namespace.

Manual rebuilding

Both the Spline Curve Mesher and Spline Fill Mesher components have a Rebuild() function, which will trigger a regeneration of the entire mesh. An option splineIndex argument can be passed on to rebuild for a specific spline.

When changing settings in the inspector rebuilding happens automatically, but when changing them through script its required to call Rebuild() after you’ve finished making changes.

Mesh Generation Callbacks

Both the Spline Curve Mesher and Spline Fill Mesher components and classes expose two triggers, designed to facilitate custom functionality. For instance, you may want to execute certain functionality whenever the spline mesh is rebuilt.

For example:

Updating a navmesh after a fence has been altered.
(Re)spawning objects along the same spline
Updating game logic data that depends on the spline
Adding components to the created mesh segments (eg. making meshes breakable)

All in all, this is an excellent way to integrate the tool with custom workflows.

Unlike the Events exposed in the inspector callbacks are entirely code-based, and can be subscribed to. A bare bones example looks like this:

using System;
using UnityEngine;
using sc.splines.mesher.runtime;

[ExecuteAlways] //Ensure the OnEnable and OnDisable functions fire outside of play mode
public class RebuildEventExample : MonoBehaviour
{
    public SplineMesher splineMesher;

    private void OnEnable()
    {
        //Subscribe
        SplineMesher.onPostRebuildMesh += OnPostRebuild;
    }

    private void OnPostRebuild(SplineMesher instance)
    {
        //Is the instance being rebuild the one we want to work with
        if (instance == splineMesher)
        {
            //Execute something
        }
    }

    private void OnDisable()
    {
        //Unsubscribe
        SplineMesher.onPostRebuildMesh -= OnPostRebuild;
    }
}

There’s also the onPreRebuildMesh callback, that executes before the mesh is being rebuild.

Collision/Trigger Callbacks

The SplineMeshSegment class holds generic collision and trigger enter/stay/exit events that can be subscribed to. The possibilities are endless so two generic examples are demonstrated here.

A Spline Mesh Segment represents an individual mesh objects created for a spline, with a Mesh Collider attached.

using sc.splinemesher.pro.runtime;
using Unity.Mathematics;
using UnityEngine;
using UnityEngine.Splines;

public class CollisionCallbacksExample : MonoBehaviour
{
    void Start()
    {
        SplineMeshSegment.onCollisionEnter += OnCollisionEnterSpline;
        
        //Similarly, there's a "onCollisionExit" event

        SplineMeshSegment.onTriggerStay += OnTriggerStaySpline;
        //There's also "onTriggerEnter and onTriggerExit" events"
    }
    
    private void OnCollisionEnterSpline(SplineMeshSegment splineMeshSegment, Collision other)
    {
        //Something collided with this spline mesh segment
        
        //You can perform normal checks here (eg layer mask, components, etc...) to see if the event is relevant to you
        if(other.gameObject.CompareTag("Player") == false) return;
        
        //You can traverse upwards to get the related Spline Mesher component, and thus also the spline this segment was made from
        SplineMesher mesher = splineMeshSegment.Container.Owner;

        SplineContainer splineContainer = mesher.SplineContainer;
        int splineIndex = splineMeshSegment.Container.SplineIndex;
        
        Spline spline = splineContainer.Splines[splineIndex];
    }
    
    private void OnTriggerStaySpline(SplineMeshSegment splineMeshSegment, Collider other)
    {
        //Collider is inside of the spline mesh segment's trigger volume. 
        //Reminder: Convex mesh colliders cannot be made triggers
        
        //Example: A player is inside a wind tube mesh, push it forward along the spline
        SplineMesher mesher = splineMeshSegment.Container.Owner;

        SplineContainer splineContainer = mesher.SplineContainer;
        int splineIndex = splineMeshSegment.Container.SplineIndex;
        
        Spline spline = splineContainer.Splines[splineIndex];

        //Sample the forward direction of the spline nearest the collider
        SplineUtility.GetNearestPoint(spline, other.transform.position, out float3 nearestPoint, out float t);
        float3 forward = math.normalize(spline.EvaluateTangent(t));
        
        Rigidbody rb = other.GetComponent();
        rb.AddForce(forward * 2f, ForceMode.VelocityChange);
    }
    
    void OnDestroy()
    {
        SplineMeshSegment.onCollisionEnter -= OnCollisionEnterSpline;
        SplineMeshSegment.onTriggerStay -= OnTriggerStaySpline;
    }
}