Example #1
0
void Group::GenerateShellAndMesh(void) {
    bool prevBooleanFailed = booleanFailed;
    booleanFailed = false;

    Group *srcg = this;

    thisShell.Clear();
    thisMesh.Clear();
    runningShell.Clear();
    runningMesh.Clear();

    // Don't attempt a lathe or extrusion unless the source section is good:
    // planar and not self-intersecting.
    bool haveSrc = true;
    if(type == EXTRUDE || type == LATHE) {
        Group *src = SK.GetGroup(opA);
        if(src->polyError.how != POLY_GOOD) {
            haveSrc = false;
        }
    }

    if(type == TRANSLATE || type == ROTATE) {
        // A step and repeat gets merged against the group's prevous group,
        // not our own previous group.
        srcg = SK.GetGroup(opA);

        GenerateForStepAndRepeat<SShell>(&(srcg->thisShell), &thisShell);
        GenerateForStepAndRepeat<SMesh> (&(srcg->thisMesh),  &thisMesh);
    } else if(type == EXTRUDE && haveSrc) {
        Group *src = SK.GetGroup(opA);
        Vector translate = Vector::From(h.param(0), h.param(1), h.param(2));

        Vector tbot, ttop;
        if(subtype == ONE_SIDED) {
            tbot = Vector::From(0, 0, 0); ttop = translate.ScaledBy(2);
        } else {
            tbot = translate.ScaledBy(-1); ttop = translate.ScaledBy(1);
        }

        SBezierLoopSetSet *sblss = &(src->bezierLoops);
        SBezierLoopSet *sbls;
        for(sbls = sblss->l.First(); sbls; sbls = sblss->l.NextAfter(sbls)) {
            int is = thisShell.surface.n;
            // Extrude this outer contour (plus its inner contours, if present)
            thisShell.MakeFromExtrusionOf(sbls, tbot, ttop, color);

            // And for any plane faces, annotate the model with the entity for
            // that face, so that the user can select them with the mouse.
            Vector onOrig = sbls->point;
            int i;
            for(i = is; i < thisShell.surface.n; i++) {
                SSurface *ss = &(thisShell.surface.elem[i]);
                hEntity face = Entity::NO_ENTITY;

                Vector p = ss->PointAt(0, 0),
                       n = ss->NormalAt(0, 0).WithMagnitude(1);
                double d = n.Dot(p);

                if(i == is || i == (is + 1)) {
                    // These are the top and bottom of the shell.
                    if(fabs((onOrig.Plus(ttop)).Dot(n) - d) < LENGTH_EPS) {
                        face = Remap(Entity::NO_ENTITY, REMAP_TOP);
                        ss->face = face.v;
                    }
                    if(fabs((onOrig.Plus(tbot)).Dot(n) - d) < LENGTH_EPS) {
                        face = Remap(Entity::NO_ENTITY, REMAP_BOTTOM);
                        ss->face = face.v;
                    }
                    continue;
                }

                // So these are the sides
                if(ss->degm != 1 || ss->degn != 1) continue;

                Entity *e;
                for(e = SK.entity.First(); e; e = SK.entity.NextAfter(e)) {
                    if(e->group.v != opA.v) continue;
                    if(e->type != Entity::LINE_SEGMENT) continue;

                    Vector a = SK.GetEntity(e->point[0])->PointGetNum(),
                           b = SK.GetEntity(e->point[1])->PointGetNum();
                    a = a.Plus(ttop);
                    b = b.Plus(ttop);
                    // Could get taken backwards, so check all cases.
                    if((a.Equals(ss->ctrl[0][0]) && b.Equals(ss->ctrl[1][0])) ||
                       (b.Equals(ss->ctrl[0][0]) && a.Equals(ss->ctrl[1][0])) ||
                       (a.Equals(ss->ctrl[0][1]) && b.Equals(ss->ctrl[1][1])) ||
                       (b.Equals(ss->ctrl[0][1]) && a.Equals(ss->ctrl[1][1])))
                    {
                        face = Remap(e->h, REMAP_LINE_TO_FACE);
                        ss->face = face.v;
                        break;
                    }
                }
            }
        }
    } else if(type == LATHE && haveSrc) {
        Group *src = SK.GetGroup(opA);

        Vector pt   = SK.GetEntity(predef.origin)->PointGetNum(),
               axis = SK.GetEntity(predef.entityB)->VectorGetNum();
        axis = axis.WithMagnitude(1);

        SBezierLoopSetSet *sblss = &(src->bezierLoops);
        SBezierLoopSet *sbls;
        for(sbls = sblss->l.First(); sbls; sbls = sblss->l.NextAfter(sbls)) {
            thisShell.MakeFromRevolutionOf(sbls, pt, axis, color, this);
        }
    } else if(type == LINKED) {
        // The imported shell or mesh are copied over, with the appropriate
        // transformation applied. We also must remap the face entities.
        Vector offset = {
            SK.GetParam(h.param(0))->val,
            SK.GetParam(h.param(1))->val,
            SK.GetParam(h.param(2))->val };
        Quaternion q = {
            SK.GetParam(h.param(3))->val,
            SK.GetParam(h.param(4))->val,
            SK.GetParam(h.param(5))->val,
            SK.GetParam(h.param(6))->val };

        thisMesh.MakeFromTransformationOf(&impMesh, offset, q, scale);
        thisMesh.RemapFaces(this, 0);

        thisShell.MakeFromTransformationOf(&impShell, offset, q, scale);
        thisShell.RemapFaces(this, 0);
    }

    if(srcg->meshCombine != COMBINE_AS_ASSEMBLE) {
        thisShell.MergeCoincidentSurfaces();
    }

    // So now we've got the mesh or shell for this group. Combine it with
    // the previous group's mesh or shell with the requested Boolean, and
    // we're done.

    Group *prevg = srcg->RunningMeshGroup();

    if(prevg->runningMesh.IsEmpty() && thisMesh.IsEmpty() && !forceToMesh) {
        SShell *prevs = &(prevg->runningShell);
        GenerateForBoolean<SShell>(prevs, &thisShell, &runningShell,
            srcg->meshCombine);

        if(srcg->meshCombine != COMBINE_AS_ASSEMBLE) {
            runningShell.MergeCoincidentSurfaces();
        }

        // If the Boolean failed, then we should note that in the text screen
        // for this group.
        booleanFailed = runningShell.booleanFailed;
        if(booleanFailed != prevBooleanFailed) {
            SS.ScheduleShowTW();
        }
    } else {
        SMesh prevm, thism;
        prevm = {};
        thism = {};

        prevm.MakeFromCopyOf(&(prevg->runningMesh));
        prevg->runningShell.TriangulateInto(&prevm);

        thism.MakeFromCopyOf(&thisMesh);
        thisShell.TriangulateInto(&thism);

        SMesh outm = {};
        GenerateForBoolean<SMesh>(&prevm, &thism, &outm, srcg->meshCombine);

        // And make sure that the output mesh is vertex-to-vertex.
        SKdNode *root = SKdNode::From(&outm);
        root->SnapToMesh(&outm);
        root->MakeMeshInto(&runningMesh);

        outm.Clear();
        thism.Clear();
        prevm.Clear();
    }

    displayDirty = true;
}
Example #2
0
//-----------------------------------------------------------------------------
// Trim this surface against the specified shell, in the way that's appropriate
// for the specified Boolean operation type (and which operand we are). We
// also need a pointer to the shell that contains our own surface, since that
// contains our original trim curves.
//-----------------------------------------------------------------------------
SSurface SSurface::MakeCopyTrimAgainst(SShell *parent,
                                       SShell *sha, SShell *shb,
                                       SShell *into,
                                       int type)
{
    bool opA = (parent == sha);
    SShell *agnst = opA ? shb : sha;

    SSurface ret;
    // The returned surface is identical, just the trim curves change
    ret = *this;
    ret.trim = {};

    // First, build a list of the existing trim curves; update them to use
    // the split curves.
    STrimBy *stb;
    for(stb = trim.First(); stb; stb = trim.NextAfter(stb)) {
        STrimBy stn = *stb;
        stn.curve = (parent->curve.FindById(stn.curve))->newH;
        ret.trim.Add(&stn);
    }

    if(type == SShell::AS_DIFFERENCE && !opA) {
        // The second operand of a Boolean difference gets turned inside out
        ret.Reverse();
    }

    // Build up our original trim polygon; remember the coordinates could
    // be changed if we just flipped the surface normal, and we are using
    // the split curves (not the original curves).
    SEdgeList orig = {};
    ret.MakeEdgesInto(into, &orig, AS_UV);
    ret.trim.Clear();
    // which means that we can't necessarily use the old BSP...
    SBspUv *origBsp = SBspUv::From(&orig, &ret);

    // And now intersect the other shell against us
    SEdgeList inter = {};

    SSurface *ss;
    for(ss = agnst->surface.First(); ss; ss = agnst->surface.NextAfter(ss)) {
        SCurve *sc;
        for(sc = into->curve.First(); sc; sc = into->curve.NextAfter(sc)) {
            if(sc->source != SCurve::FROM_INTERSECTION) continue;
            if(opA) {
                if(sc->surfA.v != h.v || sc->surfB.v != ss->h.v) continue;
            } else {
                if(sc->surfB.v != h.v || sc->surfA.v != ss->h.v) continue;
            }

            int i;
            for(i = 1; i < sc->pts.n; i++) {
                Vector a = sc->pts.elem[i-1].p,
                       b = sc->pts.elem[i].p;

                Point2d auv, buv;
                ss->ClosestPointTo(a, &(auv.x), &(auv.y));
                ss->ClosestPointTo(b, &(buv.x), &(buv.y));

                int c = (ss->bsp) ? ss->bsp->ClassifyEdge(auv, buv, ss) : SBspUv::OUTSIDE;
                if(c != SBspUv::OUTSIDE) {
                    Vector ta = Vector::From(0, 0, 0);
                    Vector tb = Vector::From(0, 0, 0);
                    ret.ClosestPointTo(a, &(ta.x), &(ta.y));
                    ret.ClosestPointTo(b, &(tb.x), &(tb.y));

                    Vector tn = ret.NormalAt(ta.x, ta.y);
                    Vector sn = ss->NormalAt(auv.x, auv.y);

                    // We are subtracting the portion of our surface that
                    // lies in the shell, so the in-plane edge normal should
                    // point opposite to the surface normal.
                    bool bkwds = true;
                    if((tn.Cross(b.Minus(a))).Dot(sn) < 0) bkwds = !bkwds;
                    if(type == SShell::AS_DIFFERENCE && !opA) bkwds = !bkwds;
                    if(bkwds) {
                        inter.AddEdge(tb, ta, sc->h.v, 1);
                    } else {
                        inter.AddEdge(ta, tb, sc->h.v, 0);
                    }
                }
            }
        }
    }

    // Record all the points where more than two edges join, which I will call
    // the choosing points. If two edges join at a non-choosing point, then
    // they must either both be kept or both be discarded (since that would
    // otherwise create an open contour).
    SPointList choosing = {};
    SEdge *se;
    for(se = orig.l.First(); se; se = orig.l.NextAfter(se)) {
        choosing.IncrementTagFor(se->a);
        choosing.IncrementTagFor(se->b);
    }
    for(se = inter.l.First(); se; se = inter.l.NextAfter(se)) {
        choosing.IncrementTagFor(se->a);
        choosing.IncrementTagFor(se->b);
    }
    SPoint *sp;
    for(sp = choosing.l.First(); sp; sp = choosing.l.NextAfter(sp)) {
        if(sp->tag == 2) {
            sp->tag = 1;
        } else {
            sp->tag = 0;
        }
    }
    choosing.l.RemoveTagged();

    // The list of edges to trim our new surface, a combination of edges from
    // our original and intersecting edge lists.
    SEdgeList final = {};

    while(orig.l.n > 0) {
        SEdgeList chain = {};
        FindChainAvoiding(&orig, &chain, &choosing);

        // Arbitrarily choose an edge within the chain to classify; they
        // should all be the same, though.
        se = &(chain.l.elem[chain.l.n/2]);

        Point2d auv  = (se->a).ProjectXy(),
                buv  = (se->b).ProjectXy();

        Vector pt, enin, enout, surfn;
        ret.EdgeNormalsWithinSurface(auv, buv, &pt, &enin, &enout, &surfn,
                                        se->auxA, into, sha, shb);

        int indir_shell, outdir_shell, indir_orig, outdir_orig;

        indir_orig  = SShell::INSIDE;
        outdir_orig = SShell::OUTSIDE;

        agnst->ClassifyEdge(&indir_shell, &outdir_shell,
                            ret.PointAt(auv), ret.PointAt(buv), pt,
                            enin, enout, surfn);

        if(KeepEdge(type, opA, indir_shell, outdir_shell,
                               indir_orig,  outdir_orig))
        {
            for(se = chain.l.First(); se; se = chain.l.NextAfter(se)) {
                final.AddEdge(se->a, se->b, se->auxA, se->auxB);
            }
        }
        chain.Clear();
    }
Example #3
0
//-----------------------------------------------------------------------------
// Does the given point lie on our shell? There are many cases; inside and
// outside are obvious, but then there's all the edge-on-edge and edge-on-face
// possibilities.
//
// To calculate, we intersect a ray through p with our shell, and classify
// using the closest intersection point. If the ray hits a surface on edge,
// then just reattempt in a different random direction.
//-----------------------------------------------------------------------------
bool SShell::ClassifyEdge(int *indir, int *outdir,
                          Vector ea, Vector eb,
                          Vector p,
                          Vector edge_n_in, Vector edge_n_out, Vector surf_n)
{
    List<SInter> l;
    ZERO(&l);

    srand(0);

    // First, check for edge-on-edge
    int edge_inters = 0;
    Vector inter_surf_n[2], inter_edge_n[2];
    SSurface *srf;
    for(srf = surface.First(); srf; srf = surface.NextAfter(srf)) {
        if(srf->LineEntirelyOutsideBbox(ea, eb, true)) continue;

        SEdgeList *sel = &(srf->edges);
        SEdge *se;
        for(se = sel->l.First(); se; se = sel->l.NextAfter(se)) {
            if((ea.Equals(se->a) && eb.Equals(se->b)) ||
               (eb.Equals(se->a) && ea.Equals(se->b)) ||
                p.OnLineSegment(se->a, se->b))
            {
                if(edge_inters < 2) {
                    // Edge-on-edge case
                    Point2d pm;
                    srf->ClosestPointTo(p,  &pm, false);
                    // A vector normal to the surface, at the intersection point
                    inter_surf_n[edge_inters] = srf->NormalAt(pm);
                    // A vector normal to the intersecting edge (but within the
                    // intersecting surface) at the intersection point, pointing
                    // out.
                    inter_edge_n[edge_inters] =
                      (inter_surf_n[edge_inters]).Cross((se->b).Minus((se->a)));
                }

                edge_inters++;
            }
        }
    }

    if(edge_inters == 2) {
        // TODO, make this use the appropriate curved normals
        double dotp[2];
        for(int i = 0; i < 2; i++) {
            dotp[i] = edge_n_out.DirectionCosineWith(inter_surf_n[i]);
        }

        if(fabs(dotp[1]) < DOTP_TOL) {
            SWAP(double, dotp[0],         dotp[1]);
            SWAP(Vector, inter_surf_n[0], inter_surf_n[1]);
            SWAP(Vector, inter_edge_n[0], inter_edge_n[1]);
        }

        int coinc = (surf_n.Dot(inter_surf_n[0])) > 0 ? COINC_SAME : COINC_OPP;

        if(fabs(dotp[0]) < DOTP_TOL && fabs(dotp[1]) < DOTP_TOL) {
            // This is actually an edge on face case, just that the face
            // is split into two pieces joining at our edge.
            *indir  = coinc;
            *outdir = coinc;
        } else if(fabs(dotp[0]) < DOTP_TOL && dotp[1] > DOTP_TOL) {
            if(edge_n_out.Dot(inter_edge_n[0]) > 0) {
                *indir  = coinc;
                *outdir = OUTSIDE;
            } else {
                *indir  = INSIDE;
                *outdir = coinc;
            }
        } else if(fabs(dotp[0]) < DOTP_TOL && dotp[1] < -DOTP_TOL) {
            if(edge_n_out.Dot(inter_edge_n[0]) > 0) {
                *indir  = coinc;
                *outdir = INSIDE;
            } else {
                *indir  = OUTSIDE;
                *outdir = coinc;
            }
        } else if(dotp[0] > DOTP_TOL && dotp[1] > DOTP_TOL) {
            *indir  = INSIDE;
            *outdir = OUTSIDE;
        } else if(dotp[0] < -DOTP_TOL && dotp[1] < -DOTP_TOL) {
            *indir  = OUTSIDE;
            *outdir = INSIDE;
        } else {
            // Edge is tangent to the shell at shell's edge, so can't be
            // a boundary of the surface.
            return false;
        }
        return true;
    }

    if(edge_inters != 0) dbp("bad, edge_inters=%d", edge_inters);

    // Next, check for edge-on-surface. The ray-casting for edge-inside-shell
    // would catch this too, but test separately, for speed (since many edges
    // are on surface) and for numerical stability, so we don't pick up
    // the additional error from the line intersection.

    for(srf = surface.First(); srf; srf = surface.NextAfter(srf)) {
        if(srf->LineEntirelyOutsideBbox(ea, eb, true)) continue;

        Point2d puv;
        srf->ClosestPointTo(p, &(puv.x), &(puv.y), false);
        Vector pp = srf->PointAt(puv);

        if((pp.Minus(p)).Magnitude() > LENGTH_EPS) continue;
        Point2d dummy = { 0, 0 };
        int c = srf->bsp->ClassifyPoint(puv, dummy, srf);
        if(c == SBspUv::OUTSIDE) continue;

        // Edge-on-face (unless edge-on-edge above superceded)
        Point2d pin, pout;
        srf->ClosestPointTo(p.Plus(edge_n_in),  &pin,  false);
        srf->ClosestPointTo(p.Plus(edge_n_out), &pout, false);

        Vector surf_n_in  = srf->NormalAt(pin),
               surf_n_out = srf->NormalAt(pout);

        *indir  = ClassifyRegion(edge_n_in,  surf_n_in,  surf_n);
        *outdir = ClassifyRegion(edge_n_out, surf_n_out, surf_n);
        return true;
    }

    // Edge is not on face or on edge; so it's either inside or outside
    // the shell, and we'll determine which by raycasting.
    int cnt = 0;
    for(;;) {
        // Cast a ray in a random direction (two-sided so that we test if
        // the point lies on a surface, but use only one side for in/out
        // testing)
        Vector ray = Vector::From(Random(1), Random(1), Random(1));

        AllPointsIntersecting(
            p.Minus(ray), p.Plus(ray), &l, false, true, false);

        // no intersections means it's outside
        *indir  = OUTSIDE;
        *outdir = OUTSIDE;
        double dmin = VERY_POSITIVE;
        bool onEdge = false;
        edge_inters = 0;

        SInter *si;
        for(si = l.First(); si; si = l.NextAfter(si)) {
            double t = ((si->p).Minus(p)).DivPivoting(ray);
            if(t*ray.Magnitude() < -LENGTH_EPS) {
                // wrong side, doesn't count
                continue;
            }

            double d = ((si->p).Minus(p)).Magnitude();

            // We actually should never hit this case; it should have been
            // handled above.
            if(d < LENGTH_EPS && si->onEdge) {
                edge_inters++;
            }

            if(d < dmin) {
                dmin = d;
                // Edge does not lie on surface; either strictly inside
                // or strictly outside
                if((si->surfNormal).Dot(ray) > 0) {
                    *indir  = INSIDE;
                    *outdir = INSIDE;
                } else {
                    *indir  = OUTSIDE;
                    *outdir = OUTSIDE;
                }
                onEdge = si->onEdge;
            }
        }
        l.Clear();

        // If the point being tested lies exactly on an edge of the shell,
        // then our ray always lies on edge, and that's okay. Otherwise
        // try again in a different random direction.
        if(!onEdge) break;
        if(cnt++ > 5) {
            dbp("can't find a ray that doesn't hit on edge!");
            dbp("on edge = %d, edge_inters = %d", onEdge, edge_inters);
            SS.nakedEdges.AddEdge(ea, eb);
            break;
        }
    }

    return true;
}