public static bool GenerateExtrudedShapeAsset(CSGBrushMeshAsset brushMeshAsset, Curve2D shape, Path path, int curveSegments, CSGSurfaceAsset[] surfaceAssets, ref SurfaceDescription[] surfaceDescriptions)
{
var shapeVertices = new List <Vector2>();
var shapeSegmentIndices = new List <int>();
GetPathVertices(shape, curveSegments, shapeVertices, shapeSegmentIndices);
Vector2[][] polygonVerticesArray;
int[][] polygonIndicesArray;
if (!Decomposition.ConvexPartition(shapeVertices, shapeSegmentIndices,
out polygonVerticesArray,
out polygonIndicesArray))
{
return(false);
}
// TODO: make each extruded quad split into two triangles when it's not a perfect plane,
// split it to make sure it's convex
// TODO: make it possible to smooth (parts) of the shape
// TODO: make materials work well
// TODO: make it possible to 'draw' shapes on any surface
// TODO: make path work as a spline, with subdivisions
// TODO: make this work well with twisted rotations
// TODO: make shape/path subdivisions be configurable / automatic
var subMeshes = new List <CSGBrushSubMesh>();
for (int p = 0; p < polygonVerticesArray.Length; p++)
{
var polygonVertices = polygonVerticesArray[p];
var segmentIndices = polygonIndicesArray[p];
var shapeSegments = polygonVertices.Length;
for (int s = 0; s < path.segments.Length - 1; s++)
{
var pathPointA = path.segments[s];
var pathPointB = path.segments[s + 1];
int subSegments = 1;
var offsetQuaternion = pathPointB.rotation * Quaternion.Inverse(pathPointA.rotation);
var offsetEuler = offsetQuaternion.eulerAngles;
if (offsetEuler.x > 180)
{
offsetEuler.x = 360 - offsetEuler.x;
}
if (offsetEuler.y > 180)
{
offsetEuler.y = 360 - offsetEuler.y;
}
if (offsetEuler.z > 180)
{
offsetEuler.z = 360 - offsetEuler.z;
}
var maxAngle = Mathf.Max(offsetEuler.x, offsetEuler.y, offsetEuler.z);
if (maxAngle != 0)
{
subSegments = Mathf.Max(1, (int)Mathf.Ceil(maxAngle / 5));
}
if ((pathPointA.scale.x / pathPointA.scale.y) != (pathPointB.scale.x / pathPointB.scale.y) &&
(subSegments & 1) == 1)
{
subSegments += 1;
}
for (int n = 0; n < subSegments; n++)
{
var matrix0 = PathPoint.Lerp(ref path.segments[s], ref path.segments[s + 1], n / (float)subSegments);
var matrix1 = PathPoint.Lerp(ref path.segments[s], ref path.segments[s + 1], (n + 1) / (float)subSegments);
// TODO: this doesn't work if top and bottom polygons intersect
// => need to split into two brushes then, invert one of the two brushes
var invertDot = Vector3.Dot(matrix0.MultiplyVector(Vector3.forward).normalized, (matrix1.MultiplyPoint(shapeVertices[0]) - matrix0.MultiplyPoint(shapeVertices[0])).normalized);
if (invertDot == 0.0f)
{
continue;
}
Vector3[] vertices;
if (invertDot < 0)
{
var m = matrix0; matrix0 = matrix1; matrix1 = m;
}
if (!GetExtrudedVertices(polygonVertices, matrix0, matrix1, out vertices))
{
continue;
}
var subMesh = new CSGBrushSubMesh();
CreateExtrudedSubMesh(subMesh, shapeSegments, segmentIndices, 0, 1, vertices, surfaceAssets, surfaceDescriptions);
subMeshes.Add(subMesh);
}
}
}
brushMeshAsset.SubMeshes = subMeshes.ToArray();
brushMeshAsset.CalculatePlanes();
brushMeshAsset.OnValidate();
brushMeshAsset.SetDirty();
return(true);
}