Examples with BVTree maspack.geometry.BVTree used on opensource projects

Example 6 with BVTree

use of maspack.geometry.BVTree in project artisynth_core by artisynth.

the class MFreeMuscleModel method computeAverageFiberDirection.

public static boolean computeAverageFiberDirection(Vector3d dir, Point3d pos, double rad, PolylineMesh mesh) {
    BVTree bvh = mesh.getBVTree();
    ArrayList<BVNode> nodes = new ArrayList<BVNode>();
    Matrix3d cov = new Matrix3d();
    SVDecomposition3d svd = new SVDecomposition3d();
    Vector3d tmp = new Vector3d();
    Matrix3d tmp2 = new Matrix3d();
    bvh.intersectSphere(nodes, pos, rad);
    dir.setZero();
    int nsegs = 0;
    // for computing sign of direction vector
    Vector3d segmentSum = new Vector3d();
    // System.out.println("p=[");
    for (BVNode n : nodes) {
        Boundable[] elements = n.getElements();
        for (int i = 0; i < elements.length; i++) {
            LineSegment seg = (LineSegment) elements[i];
            seg = getSegmentInsideSphere(seg, pos, rad);
            if (seg != null) {
                tmp.sub(seg.myVtx1.pnt, seg.myVtx0.pnt);
                if (tmp.norm() >= 1e-8 * rad) {
                    // System.out.println(seg.myVtx0.getPosition() + " " +
                    // seg.myVtx1.getPosition());
                    nsegs++;
                    // prepare to average directions using SVD
                    computeCov(tmp2, tmp);
                    cov.add(tmp2);
                    segmentSum.add(tmp);
                }
            }
        }
    }
    if (nsegs > 0) {
        // we are technically including both +/- directions, so
        // we have twice the number of points
        cov.scale(2.0 / (2.0 * nsegs - 1));
        try {
            svd.factor(cov);
        } catch (Exception e) {
        // System.err.println(e.getMessage());
        }
        // principal components
        tmp2 = svd.getU();
        tmp2.getColumn(0, dir);
        dir.normalize();
        // most line segments
        if (dir.dot(segmentSum) < 0) {
            dir.scale(-1);
        }
        return true;
    } else {
        return false;
    }
}

Example 7 with BVTree

use of maspack.geometry.BVTree in project artisynth_core by artisynth.

the class PointDistributor method sphereGridFill.

// fills a mesh based on a regular grid of points
public static Point3d[] sphereGridFill(PolygonalMesh mesh, double r) {
    ArrayList<Point3d> pnts = new ArrayList<Point3d>();
    RigidTransform3d trans = getPrincipalAxes(mesh);
    Point3d[] box = getTightBox(mesh, trans);
    Point3d center = new Point3d(box[0]);
    center.add(box[6]);
    center.scale(0.5);
    trans.setTranslation(center);
    Vector3d l = new Vector3d(box[0]);
    l.sub(box[6]);
    l.inverseTransform(trans);
    double alpha = 2 * Math.sqrt(2) * r;
    int nx = (int) Math.ceil(l.x / alpha) + 1;
    int ny = (int) Math.ceil(l.y / alpha) + 1;
    int nz = (int) Math.ceil(l.z / alpha) + 1;
    double xoffset = -(nx - 1) * alpha / 2;
    double yoffset = -(ny - 1) * alpha / 2;
    double zoffset = -(nz - 1) * alpha / 2;
    BVTree bvh = mesh.getBVTree();
    Vector2d coords = new Vector2d();
    Point3d nearest = new Point3d();
    BVFeatureQuery query = new BVFeatureQuery();
    Point3d p;
    for (int i = 0; i < nx; i++) {
        for (int j = 0; j < ny; j++) {
            for (int k = 0; k < nz; k++) {
                double x = i * alpha + xoffset;
                double y = j * alpha + yoffset;
                double z = k * alpha + zoffset;
                p = new Point3d(x, y, z);
                p.transform(trans);
                addIfIntersects(pnts, p, r, bvh, nearest, coords, query);
            }
        }
    }
    return pnts.toArray(new Point3d[pnts.size()]);
}

Example 8 with BVTree

use of maspack.geometry.BVTree in project artisynth_core by artisynth.

the class PointDistributor method sphereFCCFill.

// fills a mesh with spheres based on face-centered cubic packing
public static Point3d[] sphereFCCFill(PolygonalMesh mesh, double r) {
    ArrayList<Point3d> pnts = new ArrayList<Point3d>();
    RigidTransform3d trans = getPrincipalAxes(mesh);
    Point3d[] box = getTightBox(mesh, trans);
    Point3d center = new Point3d(box[0]);
    center.add(box[6]);
    center.scale(0.5);
    trans.setTranslation(center);
    Vector3d l = new Vector3d(box[0]);
    l.sub(box[6]);
    l.inverseTransform(trans);
    double alpha = 2 * Math.sqrt(2) * r;
    int nx = (int) Math.ceil(l.x / alpha) + 1;
    int ny = (int) Math.ceil(l.y / alpha) + 1;
    int nz = (int) Math.ceil(l.z / alpha) + 1;
    double xoffset = -(nx - 1) * alpha / 2;
    double yoffset = -(ny - 1) * alpha / 2;
    double zoffset = -(nz - 1) * alpha / 2;
    BVTree bvh = mesh.getBVTree();
    Vector2d coords = new Vector2d();
    Point3d nearest = new Point3d();
    BVFeatureQuery query = new BVFeatureQuery();
    Point3d p;
    for (int i = 0; i < nx; i++) {
        for (int j = 0; j < ny; j++) {
            for (int k = 0; k < nz; k++) {
                double x = i * alpha + xoffset;
                double y = j * alpha + yoffset;
                double z = k * alpha + zoffset;
                p = new Point3d(x, y, z);
                p.transform(trans);
                addIfIntersects(pnts, p, r, bvh, nearest, coords, query);
                // face centers
                if (i < nx - 1 && k < nz - 1) {
                    p = new Point3d(x + alpha / 2, y, z + alpha / 2);
                    p.transform(trans);
                    addIfIntersects(pnts, p, r, bvh, nearest, coords, query);
                }
                if (j < ny - 1 && k < nz - 1) {
                    p = new Point3d(x, y + alpha / 2, z + alpha / 2);
                    p.transform(trans);
                    addIfIntersects(pnts, p, r, bvh, nearest, coords, query);
                }
                if (i < nx - 1 && j < ny - 1) {
                    p = new Point3d(x + alpha / 2, y + alpha / 2, z);
                    p.transform(trans);
                    addIfIntersects(pnts, p, r, bvh, nearest, coords, query);
                }
            }
        }
    }
    return pnts.toArray(new Point3d[pnts.size()]);
}