public static bool GenerateMeshFromSpline <SplinePointCustomData>(Spline.Spline spline, Transform transform, int subdivisions, float radius, int smoothingIterations, Vector2 customDataDefault, ref Mesh mesh)
where SplinePointCustomData : ISplinePointCustomData
{
var splinePoints = spline.GetComponentsInChildren <SplinePoint>();
if (splinePoints.Length < 2)
{
return(false);
}
var splinePointCount = splinePoints.Length;
if (spline._closed && splinePointCount > 2)
{
splinePointCount++;
}
var points = new Vector3[(splinePointCount - 1) * 3 + 1];
if (!SplineInterpolation.GenerateCubicSplineHull(splinePoints, points, spline._closed))
{
return(false);
}
// Sample spline
// Estimate total length of spline and use this to compute a sample count
var lengthEst = 0f;
for (int i = 1; i < splinePointCount; i++)
{
lengthEst += (splinePoints[i % splinePoints.Length].transform.position - splinePoints[i - 1].transform.position).magnitude;
}
lengthEst = Mathf.Max(lengthEst, 1f);
var spacing = 16f / Mathf.Pow(2f, subdivisions + 1);
var pointCount = Mathf.CeilToInt(lengthEst / spacing);
pointCount = Mathf.Max(pointCount, 1);
var sampledPtsOnSpline = new Vector3[pointCount];
var sampledPtsOffSpline = new Vector3[pointCount];
var customData = new Vector2[pointCount];
// First set of sample points lie on spline
sampledPtsOnSpline[0] = points[0];
customData[0] = customDataDefault;
if (splinePoints[0].TryGetComponent(out SplinePointCustomData customDataComp00))
{
customData[0] = customDataComp00.GetData();
}
for (var i = 1; i < pointCount; i++)
{
float t = i / (float)(pointCount - 1);
SplineInterpolation.InterpolateCubicPosition(splinePointCount, points, t, out sampledPtsOnSpline[i]);
var tpts = t * (splinePoints.Length - 1f);
var spidx = Mathf.FloorToInt(tpts);
var alpha = tpts - spidx;
var customData0 = customDataDefault;
if (splinePoints[spidx].TryGetComponent(out SplinePointCustomData customDataComp0))
{
customData0 = customDataComp0.GetData();
}
var customData1 = customDataDefault;
if (splinePoints[Mathf.Min(spidx + 1, splinePoints.Length - 1)].TryGetComponent(out SplinePointCustomData customDataComp1))
{
customData1 = customDataComp1.GetData();
}
customData[i] = Vector2.Lerp(customData0, customData1, Mathf.SmoothStep(0f, 1f, alpha));
}
// Second set of sample points lie off-spline - some distance to the right
for (var i = 0; i < pointCount; i++)
{
var ibefore = i - 1;
var iafter = i + 1;
if (!spline._closed)
{
// Not closed - clamp to range
ibefore = Mathf.Max(ibefore, 0);
iafter = Mathf.Min(iafter, pointCount - 1);
}
else
{
// Closed - wrap into range
if (ibefore < 0)
{
ibefore += pointCount;
}
iafter %= pointCount;
}
var tangent = sampledPtsOnSpline[iafter] - sampledPtsOnSpline[ibefore];
var normal = tangent;
normal.x = tangent.z;
normal.z = -tangent.x;
normal.y = 0f;
normal = normal.normalized;
sampledPtsOffSpline[i] = sampledPtsOnSpline[i] + normal * radius;
}
if (spline._closed)
{
var midPoint = Vector3.Lerp(sampledPtsOffSpline[0], sampledPtsOffSpline[sampledPtsOffSpline.Length - 1], 0.5f);
sampledPtsOffSpline[0] = sampledPtsOffSpline[sampledPtsOffSpline.Length - 1] = midPoint;
}
// Blur the second set of points to help solve overlaps or large distortions. Not perfect but helps in many cases.
if (smoothingIterations > 0)
{
var scratchPoints = new Vector3[pointCount];
// Ring buffer style access when closed spline
if (!spline._closed)
{
for (var j = 0; j < smoothingIterations; j++)
{
scratchPoints[0] = sampledPtsOffSpline[0];
scratchPoints[pointCount - 1] = sampledPtsOffSpline[pointCount - 1];
for (var i = 1; i < pointCount - 1; i++)
{
scratchPoints[i] = (sampledPtsOffSpline[i] + sampledPtsOffSpline[i + 1] + sampledPtsOffSpline[i - 1]) / 3f;
scratchPoints[i] = sampledPtsOnSpline[i] + (scratchPoints[i] - sampledPtsOnSpline[i]).normalized * radius;
}
var tmp = sampledPtsOffSpline;
sampledPtsOffSpline = scratchPoints;
scratchPoints = tmp;
}
}
else
{
for (var j = 0; j < smoothingIterations; j++)
{
for (var i = 0; i < sampledPtsOffSpline.Length; i++)
{
// Slightly odd indexing. The first and last point are the same, the indices need to wrap to either the
// second element (if overflow) or the penultimate element (if underflow) to ensure tension is maintained at ends.
var ibefore = i - 1;
var iafter = i + 1;
if (ibefore < 0)
{
ibefore = sampledPtsOffSpline.Length - 2;
}
if (iafter >= sampledPtsOffSpline.Length)
{
iafter = 1;
}
scratchPoints[i] = (sampledPtsOffSpline[i] + sampledPtsOffSpline[iafter] + sampledPtsOffSpline[ibefore]) / 3f;
scratchPoints[i] = sampledPtsOnSpline[i] + (scratchPoints[i] - sampledPtsOnSpline[i]).normalized * radius;
}
var tmp = sampledPtsOffSpline;
sampledPtsOffSpline = scratchPoints;
scratchPoints = tmp;
}
}
}
return(UpdateMesh(transform, sampledPtsOnSpline, sampledPtsOffSpline, customData, spline._closed, ref mesh));
}
public static void ExtendSpline(Spline spline)
{
var newPoint = SplinePointEditor.AddSplinePointAfter(spline.transform);
Undo.RegisterCreatedObjectUndo(newPoint, "Add Crest Spline Point");
}
public static bool GenerateMeshFromSpline(Spline.Spline spline, Transform transform, int subdivisions, float radius, int smoothingIterations, Vector2 customDataDefault, ref Mesh mesh)
{
return(GenerateMeshFromSpline <SplinePointDataNone>(spline, transform, subdivisions, radius, smoothingIterations, customDataDefault, ref mesh));
}