public static Vector3 GetTangent(this SplineSegment s, float naturalT)
{
var up = s.GetUpVector(naturalT);
var rot = s.GetRotation(naturalT);
up = rot * up;
return(Vector3.Cross(s.GetDeltaOnSpline(naturalT), up));
}
// Distorts a mesh along a spline
public static Mesh DistortAlongSpline(this Mesh sourceMesh, SplineSegment spline, Matrix4x4 meshTransform,
float splineStartTime = 0, float splineEndTime = 1, float snapDistance = 0,
SplineSegment.ESplineInterpolation splineInterpolation = SplineSegment.ESplineInterpolation.Natural)
{
var result = new Mesh();
var verts = new List <Vector3>(sourceMesh.vertices);
var meshBounds = new Bounds();
for (var i = 0; i < verts.Count; i++)
{
verts[i] = meshTransform.MultiplyPoint3x4(verts[i]);
if (i == 0)
{
meshBounds.center = verts[i];
}
else
{
meshBounds.Encapsulate(verts[i]);
}
}
//DebugHelper.DrawCube(meshBounds.center, meshBounds.extents, Quaternion.identity, Color.white, 20);
var splineLength = spline.Length;
var colors = new Color[verts.Count];
// Transform vert from mesh space to spline-axis space
for (var i = verts.Count - 1; i >= 0; i--)
{
var vert = verts[i];
// First is finding the vert on the spline axis
var normalizedVert = vert - meshBounds.min;
// Normalized vert tells us where it falls on the splines 't' axis
normalizedVert = new Vector3(
normalizedVert.x / Mathf.Max(float.Epsilon, meshBounds.size.x),
normalizedVert.y / Mathf.Max(float.Epsilon, meshBounds.size.y),
normalizedVert.z / Mathf.Max(float.Epsilon, meshBounds.size.z));
var t = Mathf.Lerp(splineStartTime, splineEndTime, normalizedVert.x);
var dist = t * splineLength;
if (dist < snapDistance)
{
t = 0;
}
var distRemaining = splineLength - dist;
if (distRemaining < snapDistance)
{
t = 1;
}
t = Mathf.Clamp01(t);
var natT = t;
if (splineInterpolation == SplineSegment.ESplineInterpolation.Uniform)
{
natT = spline.UniformToNaturalTime(t);
}
//var rotation = spline.GetRotation(natT);
var tangent = spline.GetTangent(natT);
var splineForward = Quaternion.LookRotation(tangent, spline.GetUpVector(natT));
//var axisRotation = GetAxisRotation(axis);
//var uniformT = spline.NaturalToUniformTime(t);
var pointAlongSpline = /*transform.worldToLocalMatrix**/ spline.GetUniformPointOnSpline(t);
//var vectorFromAxis = GetVectorFromAxis(vert, axis);
//var splineAdjustedVert = vert - vectorFromAxis;
verts[i] = pointAlongSpline + splineForward * new Vector3(0, vert.y, vert.z);
colors[i] = Color.Lerp(Color.black, Color.white, t);
}
result.SetVertices(verts);
result.colors = colors;
result.SetTriangles(sourceMesh.GetTriangles(0), 0);
result.SetUVs(0, new List <Vector2>(sourceMesh.uv));
return(result);
}
