| public abstract GetCurvePoints ( ) : Curves.CurvePoint[] | ||
| return | Curves.CurvePoint[] | |
private float GetLinearTimeOnCurve(float posOnCurve)
{
// this is necessary because the points on the curve are not evenly sampled, if they were we could just use dist / curveLength
var linearTime = 0f;
var points = Curve.GetCurvePoints();
var step = 1f / (points.Length - 1);
for (var i = 0; i < points.Length - 1; i++)
{
var point = points[i];
if (posOnCurve > point.DistanceOnCurve)
{
var interpolation = Mathf.InverseLerp(point.DistanceOnCurve, points[i + 1].DistanceOnCurve, posOnCurve);
linearTime = Mathf.Lerp(step * i, step * (i + 1), interpolation);
}
}
return(linearTime);
}
protected Mesh GetCurvedMesh()
{
var positionsOnCurve = _curve.GetCurvePoints();
const int wallResolution = 10;
const float radius = 0.1f;
//calculate how many vertices we need
var numVertexColumns = wallResolution + 1; //+1 for welding
var numVertexRows = positionsOnCurve.Length;
//calculate sizes
var numVertices = numVertexColumns * numVertexRows;
var numUVs = numVertices; //always
var numSideTris = wallResolution * _curve.Resolution * _curve.ControlPoints.Length * 2; //for one cap
var trisArrayLength = numSideTris * 3; //3 places in the array for each tri
//initialize arrays
var vertices = new Vector3[numVertices];
var uvs = new Vector2[numUVs];
var tris = new int[trisArrayLength];
//precalculate increments to improve performance
var angleStep = 2 * Mathf.PI / wallResolution;
var uvStepH = 1.0f / wallResolution;
var uvStepV = 1.0f / _curve.Resolution;
for (var j = 0; j < positionsOnCurve.Length; j++)
{
var curvePos = positionsOnCurve[j];
for (var i = 0; i < numVertexColumns; i++)
{
//calculate angle for that vertex on the unit circle
var angle = i * angleStep;
//"fold" the sheet around as a cylinder by placing the first and last vertex of each row at the same spot
if (i == numVertexColumns - 1)
{
angle = 0;
}
//position current vertex
var verticalVertPos = new Vector3(radius * Mathf.Cos(angle), 0, radius * Mathf.Sin(angle));
vertices[j * numVertexColumns + i] = Quaternion.LookRotation(curvePos.Normal, curvePos.Tangent) * verticalVertPos + curvePos.Position;
//calculate UVs
uvs[j * numVertexColumns + i] = new Vector2(i * uvStepH, j * uvStepV);
//create the tris
if (j == 0 || i >= numVertexColumns - 1)
{
//nothing to do on the first and last "floor" on the tris, capping is done below
//also nothing to do on the last column of vertices
continue;
}
//create 2 tris below each vertex
//6 seems like a magic number. For every vertex we draw 2 tris in this for-loop, therefore we need 2*3=6 indices in the Tris array
//offset the base by the number of slots we need for the bottom cap tris. Those will be populated once we draw the cap
int baseIndex = (j - 1) * wallResolution * 6 + i * 6;
//1st tri - below and in front
tris[baseIndex + 0] = j * numVertexColumns + i;
tris[baseIndex + 1] = j * numVertexColumns + i + 1;
tris[baseIndex + 2] = (j - 1) * numVertexColumns + i;
//2nd tri - the one it doesn't touch
tris[baseIndex + 3] = (j - 1) * numVertexColumns + i;
tris[baseIndex + 4] = j * numVertexColumns + i + 1;
tris[baseIndex + 5] = (j - 1) * numVertexColumns + i + 1;
}
}
//assign vertices, uvs and tris
var curvedMesh = new Mesh
{
name = "Curved Mesh",
vertices = vertices,
uv = uvs
};
//System.Array.Reverse(tris); // flip normals
curvedMesh.triangles = tris;
curvedMesh.RecalculateNormals();
curvedMesh.RecalculateBounds();
CalculateMeshTangents(curvedMesh);
curvedMesh.Optimize();
return(curvedMesh);
}
