Examples with FemElement3d artisynth.core.femmodels.FemElement3d used on opensource projects

Example 11 with FemElement3d

use of artisynth.core.femmodels.FemElement3d in project artisynth_core by artisynth.

the class FemDisplayProbe method getStrainValue.

// computes strain of a point inside the model based on FEM shape
// function interpolation
private static double getStrainValue(Point3d pnt, FemModel3d model) {
    Point3d loc = new Point3d();
    FemElement3d elem = model.findNearestElement(loc, pnt);
    Vector3d coords = new Vector3d();
    double strain = 0;
    if (elem != null) {
        elem.getNaturalCoordinates(coords, pnt);
        FemNode3d[] nodes = elem.getNodes();
        for (int i = 0; i < elem.numNodes(); i++) {
            strain += elem.getN(i, coords) * nodes[i].getVonMisesStrain();
        }
    }
    return strain;
}

Example 12 with FemElement3d

use of artisynth.core.femmodels.FemElement3d in project artisynth_core by artisynth.

the class MFreeMeshComp method getFaceElement.

public MFreeElement3d getFaceElement(Face face) {
    // Form the intersection of all the element dependencies of all three
    // nodes associated with the face. If the face is on the surface,
    // there should be only one element left.
    HashSet<MFreeNode3d> nodes = new HashSet<MFreeNode3d>();
    HalfEdge he0 = face.firstHalfEdge();
    HalfEdge he = he0;
    do {
        addVertexNodes(nodes, he.getHead());
        he = he.getNext();
    } while (he != he0);
    HashSet<FemElement3d> elems = null;
    for (MFreeNode3d node : nodes) {
        if (elems == null) {
            elems = new HashSet<>(node.getElementDependencies());
        } else {
            elems.retainAll(node.getElementDependencies());
        }
    }
    if (elems.size() != 1) {
        MFreeElement3d[] elemArray = elems.toArray(new MFreeElement3d[0]);
        int[] idxs = face.getVertexIndices();
        System.out.print("Error: couldn't get element for face [ ");
        for (int i = 0; i < idxs.length; i++) {
            System.out.print("" + idxs[i] + " ");
        }
        System.out.println("]");
        System.out.println("Candidate elements are:");
        for (int i = 0; i < elemArray.length; i++) {
            System.out.println(" element " + elemArray[i].getNumber());
        }
        return null;
    // ignore for now ...
    // throw new InternalErrorException (
    // "Face "+face+" associated with "+elems.size()+" elements");
    }
    return (MFreeElement3d) elems.toArray()[0];
}

Example 13 with FemElement3d

use of artisynth.core.femmodels.FemElement3d in project artisynth_core by artisynth.

the class MFreeModel3d method findNearestElement.

/**
 * Finds the nearest element and node coordinates
 * @param nearest nearest point
 * @param N shape function evaluation at point
 * @return the nearest element
 */
public FemElement3d findNearestElement(Point3d nearest, Point3d pnt, VectorNd N) {
    BVFeatureQuery query = new BVFeatureQuery();
    NearestIPointCalculator dcalc = new NearestIPointCalculator(pnt);
    query.nearestObject(getElementBVTree(), dcalc);
    FemElement3d elem = dcalc.nearestObject();
    MFreeIntegrationPoint3d ipnt = dcalc.nearestIPoint();
    nearest.set(ipnt.getPosition());
    N.set(ipnt.getShapeWeights());
    return elem;
}

Example 14 with FemElement3d

use of artisynth.core.femmodels.FemElement3d in project artisynth_core by artisynth.

the class MFreeModel3d method findNaturalCoordinates.

/**
 * Finds the containing element and node coordinates
 * @param pnt 3D point in world coordinates to find natural coordinates of
 * @param coords natural coordinates
 * @param N shape function values
 * @return the containing element if it exists
 */
public FemNode3d[] findNaturalCoordinates(Point3d pnt, Point3d coords, VectorNd N) {
    BVFeatureQuery query = new BVFeatureQuery();
    NearestIPointCalculator dcalc = new NearestIPointCalculator(pnt);
    query.nearestObject(getElementBVTree(), dcalc);
    FemElement3d elem = dcalc.nearestObject();
    MFreeIntegrationPoint3d ipnt = dcalc.nearestIPoint();
    // try to compute coords
    coords.set(ipnt.getRestPosition());
    int n = ((MFreeElement3d) elem).getNaturalCoordinates(coords, pnt, 1000, N);
    return elem.getNodes();
}

Example 15 with FemElement3d

use of artisynth.core.femmodels.FemElement3d in project artisynth_core by artisynth.

the class MFreeModel3d method computeConsistentMassMatrix.

public SparseMatrixNd computeConsistentMassMatrix() {
    int nNodes = myNodes.size();
    SparseMatrixNd M = new SparseMatrixNd(nNodes, nNodes);
    updateJacobians();
    for (FemElement3d e : myElements) {
        for (int k = 0; k < e.numIntegrationPoints(); k++) {
            IntegrationPoint3d ipnt = e.getIntegrationPoints()[k];
            IntegrationData3d idat = e.getIntegrationData()[k];
            VectorNd shapeCoords = ipnt.getShapeWeights();
            for (int i = 0; i < e.numNodes(); i++) {
                for (int j = i; j < e.numNodes(); j++) {
                    // if (e.isTermActive(i, j)) {
                    int bi = e.getNodes()[i].getNumber();
                    int bj = e.getNodes()[j].getNumber();
                    double m = myDensity * shapeCoords.get(i) * shapeCoords.get(j) * ipnt.getWeight() * ipnt.getDetF() * idat.getDetJ0();
                    M.set(bi, bj, M.get(bi, bj) + m);
                    if (i != j) {
                        M.set(bj, bi, M.get(bj, bi) + m);
                    }
                // }
                }
            }
        }
    }
    return M;
}