static void GenerateSegment(
Curve.Curve curve,
List <FrenetFrame> frames,
int tubularSegments,
float radius,
int radialSegments,
List <Vector3> vertices,
List <Vector3> normals,
List <Vector4> tangents,
int i
)
{
var u = 1f * i / tubularSegments;
var p = curve.GetPointAt(u);
var fr = frames[i];
var N = fr.Normal;
var B = fr.Binormal;
for (int j = 0; j <= radialSegments; j++)
{
float v = 1f * j / radialSegments * PI2;
var sin = Mathf.Sin(v);
var cos = Mathf.Cos(v);
Vector3 normal = (cos * N + sin * B).normalized;
vertices.Add(p + radius * normal);
normals.Add(normal);
var tangent = fr.Tangent;
tangents.Add(new Vector4(tangent.x, tangent.y, tangent.z, 0f));
}
}
public static Mesh Build(Curve.Curve curve, int tubularSegments, float radius, int radialSegments, bool closed)
{
var vertices = new List <Vector3>();
var normals = new List <Vector3>();
var tangents = new List <Vector4>();
var uvs = new List <Vector2>();
var indices = new List <int>();
var frames = curve.ComputeFrenetFrames(tubularSegments, closed);
for (int i = 0; i < tubularSegments; i++)
{
GenerateSegment(curve, frames, tubularSegments, radius, radialSegments, vertices, normals, tangents, i);
}
GenerateSegment(curve, frames, tubularSegments, radius, radialSegments, vertices, normals, tangents, (!closed) ? tubularSegments : 0);
for (int i = 0; i <= tubularSegments; i++)
{
for (int j = 0; j <= radialSegments; j++)
{
float u = 1f * j / radialSegments;
float v = 1f * i / tubularSegments;
uvs.Add(new Vector2(u, v));
}
}
for (int j = 1; j <= tubularSegments; j++)
{
for (int i = 1; i <= radialSegments; i++)
{
int a = (radialSegments + 1) * (j - 1) + (i - 1);
int b = (radialSegments + 1) * j + (i - 1);
int c = (radialSegments + 1) * j + i;
int d = (radialSegments + 1) * (j - 1) + i;
// faces
indices.Add(a); indices.Add(d); indices.Add(b);
indices.Add(b); indices.Add(d); indices.Add(c);
}
}
var mesh = new Mesh();
mesh.vertices = vertices.ToArray();
mesh.normals = normals.ToArray();
mesh.tangents = tangents.ToArray();
mesh.uv = uvs.ToArray();
mesh.SetIndices(indices.ToArray(), MeshTopology.Triangles, 0);
return(mesh);
}
