Ejemplo n.º 1
0
typename SurfaceBase<VertexType,EdgeType,TriangleType>::ctype SurfaceBase<VertexType,EdgeType,TriangleType>::minInteriorAngle(int n) const
{
    ctype minAngle = 2*M_PI;
    const std::array<int, 3>& p = triangles(n).vertices;

    for (int i=0; i<3; i++){
        StaticVector<ctype,3> a = vertices(p[(i+1)%3]) - vertices(p[i]);
        StaticVector<ctype,3> b = vertices(p[(i+2)%3]) - vertices(p[i]);

        ctype angle = acosf(a.dot(b) / (a.length() * b.length()));
        if (angle<minAngle)
            minAngle = angle;
    }

    return minAngle;
}
Ejemplo n.º 2
0
void ContactMapping<2,ctype>::build(const std::vector<std::array<ctype,2> >& coords1,  ///< The vertex coordinates of the first surface
               const std::vector<std::array<int,2> >& tri1,       ///< The triangles of the first surface
               const std::vector<std::array<ctype,2> >& coords2,  ///< The vertices of the second surface
               const std::vector<std::array<int,2> >& tri2,
                                    const DirectionFunction<2,ctype>* domainDirection,
                                    const DirectionFunction<2,ctype>* targetDirection
               )
{
    int numVertices1 = coords1.size();
    int numVertices2 = coords2.size();
    int nTri1  = tri1.size();
    int nTri2  = tri2.size();

#if 0
    printf("----- 1 -----\n");

    for (int i=0; i<nTri1; i++)
        printf("-- %d %d\n", tri1[2*i], tri1[2*i+1]);

    printf("----- 2 -----\n");

    for (int i=0; i<nTri2; i++)
        printf("-- %d %d\n", tri2[2*i], tri2[2*i+1]);
#endif

    // //////////////////////////////////////////////////
    //   Build domain surface and its normal field
    // //////////////////////////////////////////////////

    psurface_.domainVertices.resize(numVertices1);
    for (int i=0; i<numVertices1; i++)
        for (int j=0; j<2; j++)
            psurface_.domainVertices[i][j] = coords1[i][j];

    // Build the domain segments
    psurface_.domainSegments.clear();  // may contain old stuff from previous runs
    psurface_.domainSegments.resize(nTri1);
    for (int i=0; i<nTri1; i++) {
        psurface_.domainSegments[i].points[0] = tri1[i][0];
        psurface_.domainSegments[i].points[1] = tri1[i][1];
    }

    // ///////////////////////////////
    //   Build the domain normal field
    // ///////////////////////////////
    std::vector<StaticVector<ctype, 2> > domainNormals;
    std::vector<StaticVector<ctype, 2> > targetNormals;

    computeDiscreteDomainDirections(domainDirection, domainNormals);

    // //////////////////////////////////////////////////
    //   Build range surface and its normal field
    // //////////////////////////////////////////////////

    // first mark the vertices that are actually used
    psurface_.targetVertices.resize(numVertices2);
    for (int i=0; i<numVertices2; i++)
        for (int j=0; j<2; j++)
            psurface_.targetVertices[i][j] = coords2[i][j];

    // /////////////////////////////////////////////////////
    //   Build the segments-per-vertex arrays
    // /////////////////////////////////////////////////////

    std::vector<std::array<int, 2> > segPerVertex1(psurface_.domainVertices.size());
    for (size_t i=0; i<segPerVertex1.size(); i++)
        segPerVertex1[i][0] = segPerVertex1[i][1] = -1;

    for (int i=0; i<nTri1; i++) {

        //printf("segment %d:  %d %d  --  %d %d\n", i, tri2[2*i], tri2[2*i+1], used2[tri2[2*i]],used2[tri2[2*i+1]]);
        for (int j=0; j<2; j++) {

            int p = tri1[i][j];
            if (segPerVertex1[p][0]==-1)
                segPerVertex1[p][0] = i;
            else
                segPerVertex1[p][1] = i;

        }

    }

    // use this to construct the neighbor relationships between segments
    for (size_t i=0; i<psurface_.domainSegments.size(); i++) {

        int vertex0 = psurface_.domainSegments[i].points[0];
        int other0 = (segPerVertex1[vertex0][0] == i) ? segPerVertex1[vertex0][1] : segPerVertex1[vertex0][0];
        psurface_.domainSegments[i].neighbor[0] = other0;

        int vertex1 = psurface_.domainSegments[i].points[1];
        int other1 = (segPerVertex1[vertex1][0] == i) ? segPerVertex1[vertex1][1] : segPerVertex1[vertex1][0];
        psurface_.domainSegments[i].neighbor[1] = other1;

        //printf("Segment %d neighbors:  %d  %d\n", i, other0, other1);
    }



    // Build the segments-per-vertex arrays for the target vertices
    std::vector<std::array<int, 2> > segPerVertex2(psurface_.targetVertices.size());
    for (size_t i=0; i<segPerVertex2.size(); i++)
        segPerVertex2[i][0] = segPerVertex2[i][1] = -1;

    for (int i=0; i<nTri2; i++) {

        //printf("segment %d:  %d %d  --  %d %d\n", i, tri2[2*i], tri2[2*i+1], tri2[2*i], tri2[2*i+1]);
        for (int j=0; j<2; j++) {

            int p = tri2[i][j];
            if (segPerVertex2[p][0]==-1)
                segPerVertex2[p][0] = i;
            else
                segPerVertex2[p][1] = i;

        }

    }

    computeDiscreteTargetDirections(tri2, targetDirection, targetNormals);

    // ///////////////////////////////////////////////////////////////////////
    //   Project the vertices of the target surface onto the domain surface
    // ///////////////////////////////////////////////////////////////////////
    const ctype eps = 1e-10;

    for (size_t i=0; i<psurface_.targetVertices.size(); i++) {

        ctype bestLocalPos = std::numeric_limits<ctype>::max();  // init to something
        int bestSegment = -1;
        ctype bestDist = std::numeric_limits<ctype>::max();

        for (int j=0; j<psurface_.domainSegments.size(); j++) {

            const StaticVector<ctype,2>& p0 = psurface_.domainVertices[psurface_.domainSegments[j].points[0]];
            const StaticVector<ctype,2>& p1 = psurface_.domainVertices[psurface_.domainSegments[j].points[1]];

            const StaticVector<ctype,2>& n0 = domainNormals[psurface_.domainSegments[j].points[0]];
            const StaticVector<ctype,2>& n1 = domainNormals[psurface_.domainSegments[j].points[1]];

            ctype local; // the unknown...

            if (NormalProjector<ctype>::computeInverseNormalProjection(p0, p1, n0, n1,
                                                                        psurface_.targetVertices[i], local)) {

                // We want that the line from the domain surface to its projection
                // approaches the target surface from the front side, i.e., it should
                // not pass through the body represented by the target surface.
                // We do a simplified test by comparing the connecting segment
                // with the normal at the target surface and the normal at the
                // domain surface
                /** \todo Rewrite this once we have expression templates */
                StaticVector<ctype,2> base;
                StaticVector<ctype, 2> baseNormal;
                StaticVector<ctype, 2> segment;

                for (int k=0; k<2; k++) {
                    base[k]       = (1-local)*p0[k] + local*p1[k];
                    baseNormal[k] = (1-local)*n0[k] + local*n1[k];
                    segment[k]    = psurface_.targetVertices[i][k] - base[k];
                }

                ctype distance = segment.length2();

                if (segment.dot(targetNormals[i]) > -0.0001
                    && segment.dot(baseNormal) > -0.0001
                    && distance > 1e-8) {
                    //printf("aborting %g %g %g\n", segment * targetNormals[i], segment * baseNormal, distance);
                    continue;
                }

                // There may be several inverse orthogonal projections.
                // We want the shortest one.

                if (distance < bestDist) {

                    bestDist = distance;
                    bestLocalPos = local;
                    bestSegment  = j;

                }

            }

        }

        // /////////////////////////////////////////////
        //   We have found a valid projection
        // /////////////////////////////////////////////
        if (bestSegment != -1) {

            typename PSurface<1,ctype>::DomainSegment& bS = psurface_.domainSegments[bestSegment];

            if (bestLocalPos < eps) {

                // Insert as new first element
                bS.nodes.insert(bS.nodes.begin(), typename PSurface<1,ctype>::Node(0, 1, true, true, segPerVertex2[i][0], segPerVertex2[i][1]));

                // Look for left neighbor segment
                if (psurface_.domainSegments[bestSegment].neighbor[0] != -1) {

                    psurface_.domainSegments[psurface_.domainSegments[bestSegment].neighbor[0]].nodes.push_back( typename PSurface<1,ctype>::Node(1, 0, true, true,
                                                                                                  segPerVertex2[i][0], segPerVertex2[i][1]) );

                }

            } else if (bestLocalPos > 1-eps) {

                typename PSurface<1,ctype>::Node newNode(1, 0, true, true, segPerVertex2[i][0], segPerVertex2[i][1]);
                bS.nodes.push_back(newNode);

                // Look for right neighbor segment
                if (psurface_.domainSegments[bestSegment].neighbor[1] != -1) {

                    typename PSurface<1,ctype>::DomainSegment& rightNeighborSegment = psurface_.domainSegments[psurface_.domainSegments[bestSegment].neighbor[1]];
                    rightNeighborSegment.nodes.insert(rightNeighborSegment.nodes.begin(),
                                                      typename PSurface<1,ctype>::Node(0, 1, true, true, segPerVertex2[i][0], segPerVertex2[i][1]));

                }
            } else {
                int nNodes = bS.nodes.size();

                bS.nodes.resize(nNodes+1);
                int j=nNodes-1;
                for (; j>=0; j--) {
                    if (bS.nodes[j].domainLocalPosition > bestLocalPos)
                        bS.nodes[j+1] = bS.nodes[j];
                    else
                        break;
                }

                bS.nodes[j+1] = typename PSurface<1,ctype>::Node(bestLocalPos, 0, false, true, segPerVertex2[i][0], segPerVertex2[i][1]);

            }

        }

    }

    // //////////////////////////////////////////////////////////////////////
    //   Insert missing nodes that belong to vertices of the domain segment
    // //////////////////////////////////////////////////////////////////////

    for (int i=0; i<psurface_.domainSegments.size(); i++) {

        typename PSurface<1,ctype>::DomainSegment& cS = psurface_.domainSegments[i];

        // Insert node belonging to domain vertex to the segment to the left of the vertex
        if (cS.nodes.size()==0
            || !cS.nodes[0].isNodeOnVertex
            || (cS.nodes.size()==1 && cS.nodes[0].isNodeOnVertex && cS.nodes[0].domainLocalPosition > 1-eps)) {

            ctype rangeLocalPosition;
            int rangeSegment;

            if (NormalProjector<ctype>::normalProjection(psurface_.domainVertices[cS.points[0]], domainNormals[cS.points[0]],
                                                          rangeSegment, rangeLocalPosition,
                                                          tri2, coords2)) {

                typename PSurface<1,ctype>::Node newNode(0, rangeLocalPosition, true, false, rangeSegment, rangeSegment);

                cS.nodes.insert(cS.nodes.begin(), newNode);

            }

        }

        // Insert node belonging to domain vertex to the segment to the right of the vertex
        if (cS.nodes.size()==0
            || !cS.nodes.back().isNodeOnVertex
            || (cS.nodes.size()==1 && cS.nodes[0].isNodeOnVertex && cS.nodes[0].domainLocalPosition < eps)) {

            ctype rangeLocalPosition;
            int rangeSegment;

            if (NormalProjector<ctype>::normalProjection(psurface_.domainVertices[cS.points[1]], domainNormals[cS.points[1]],
                                                          rangeSegment, rangeLocalPosition,
                                                          tri2, coords2)) {

                typename PSurface<1,ctype>::Node newNode(1, rangeLocalPosition, true, false, rangeSegment, rangeSegment);

                cS.nodes.push_back(newNode);
            }

        }

    }

#if 0
    for (int i=0; i<psurface_.domainSegments.size(); i++) {
        printf(" --- segment %d ---   (%d  -->  %d)\n", i,
               psurface_.domainSegments[i].points[0],psurface_.domainSegments[i].points[1]);
        for (int j=0; j<psurface_.domainSegments[i].nodes.size(); j++)
            std::cout << psurface_.domainSegments[i].nodes[j];

        std::cout << std::endl;
    }
#endif

    // /////////////////////////////////////////////////////
    //   Insert edges
    // /////////////////////////////////////////////////////

    /** \todo Only works if the relevant domain is a single connected component */
    for (int i=0; i<psurface_.domainSegments.size(); i++) {

        std::vector<typename PSurface<1,ctype>::Node>& nodes = psurface_.domainSegments[i].nodes;

        ////////////////////////////////
        for (int j=0; j<int(nodes.size())-1; j++) {

            if (nodes[j].rangeSegments[0] == nodes[j+1].rangeSegments[0])
                nodes[j].rightRangeSegment = nodes[j].rangeSegments[0];
            else if (nodes[j].rangeSegments[0] == nodes[j+1].rangeSegments[1])
                nodes[j].rightRangeSegment = nodes[j].rangeSegments[0];
            else if (nodes[j].rangeSegments[1] == nodes[j+1].rangeSegments[0])
                nodes[j].rightRangeSegment = nodes[j].rangeSegments[1];
            else if (nodes[j].rangeSegments[1] == nodes[j+1].rangeSegments[1])
                nodes[j].rightRangeSegment = nodes[j].rangeSegments[1];
            else
                throw(std::runtime_error("Segment of the PSurface<1> data structure is inconsistent!"));

            if (nodes[j].rightRangeSegment == -1)
                throw(std::runtime_error("Segment of the PSurface<1> data structure is inconsistent!"));

        }

    }

}
Ejemplo n.º 3
0
ctype CircularPatch<ctype>::distanceTo(const StaticVector<ctype,3> &p) const
{
    int i, j;
    ctype bestDist = std::numeric_limits<ctype>::max();

    // check point against triangles
    for (j=0; j<size(); j++){

        const DomainTriangle<ctype>& cT = par->triangles(triangles[j]);

        StaticVector<ctype,3> triPoints[3];
        triPoints[0] = par->vertices(cT.vertices[0]);
        triPoints[1] = par->vertices(cT.vertices[1]);
        triPoints[2] = par->vertices(cT.vertices[2]);

        // local base
        StaticVector<ctype,3> a = triPoints[1] - triPoints[0];
        StaticVector<ctype,3> b = triPoints[2] - triPoints[0];
        StaticVector<ctype,3> c = a.cross(b);
        c.normalize();

        StaticVector<ctype,3> x = p - triPoints[0];

        // write x in the new base  (Cramer's rule)
        StaticMatrix<ctype,3> numerator(a, b, c);
        StaticMatrix<ctype,3> alphaMat(x, b, c);
        StaticMatrix<ctype,3> betaMat(a, x, c);
        StaticMatrix<ctype,3> gammaMat(a, b, x);

        ctype alpha = alphaMat.det()/numerator.det();
        ctype beta  = betaMat.det()/numerator.det();
        ctype gamma = gammaMat.det()/numerator.det();

        // check whether orthogonal projection onto the ab plane is in triangle
        bool isIn = alpha>=0 && beta>=0 && (1-alpha-beta)>=0;

        if (isIn && fabs(gamma)<bestDist){

            //              printf("a(%1.2f %1.2f %1.2f) b(%1.2f %1.2f %1.2f)  c(%1.2f %1.2f %1.2f)  x(%1.2f %1.2f %1.2f)\n",
            //                     a.x, a.y, a.z, b.x, b.y, b.z, c.x, c.y, c.z, x.x, x.y, x.z);

            //              printf("tri: %d, alpha = %f, beta = %f, gamma = %f\n", j, alpha, beta, gamma);

            bestDist = fabs(gamma);
        }
    }

    // check point against edges
    for (i=0; i<size(); i++){
        for (j=0; j<3; j++){

            const DomainTriangle<ctype>& cT = par->triangles(triangles[i]);

            StaticVector<ctype,3> from = par->vertices(cT.vertices[j]);
            StaticVector<ctype,3> to   = par->vertices(cT.vertices[(j+1)%3]);

            StaticVector<ctype,3> edge = to - from;

            ctype projectLength = edge.dot(p - from)/edge.length();
            StaticVector<ctype,3> projection = edge/edge.length() * projectLength;

            ctype orthoDist = ((p-from) - projection).length();

            if (projectLength>=0 && projectLength<=edge.length() && orthoDist<bestDist)
                bestDist = orthoDist;
        }
    }

    // check point against vertices
    for (i=0; i<size(); i++){
        for (j=0; j<3; j++){
            ctype dist = (p - par->vertices(par->triangles(triangles[i]).vertices[j])).length();
            if (dist < bestDist){
                bestDist = dist;
            }
        }
    }

    return bestDist;
}