diff --git a/constraint.cpp b/constraint.cpp
index e0a043b..cef9980 100644
--- a/constraint.cpp
+++ b/constraint.cpp
@@ -126,6 +126,10 @@ void Constraint::MenuConstrain(int id) {
                 c.type = PT_ON_CIRCLE;
                 c.ptA = gs.point[0];
                 c.entityA = gs.entity[0];
+            } else if(gs.points == 1 && gs.faces == 1 && gs.n == 2) {
+                c.type = PT_ON_FACE;
+                c.ptA = gs.point[0];
+                c.entityA = gs.face[0];
             } else {
                 Error("Bad selection for on point / curve / plane constraint.");
                 return;
@@ -547,6 +551,16 @@ void Constraint::Generate(IdList<Equation,hEquation> *l) {
                         SS.GetEntity(ptA)->PointGetExprs(), entityA), 0);
             break;
 
+        case PT_ON_FACE: {
+            // a plane, n dot (p - p0) = 0
+            ExprVector p = SS.GetEntity(ptA)->PointGetExprs();
+            Entity *f = SS.GetEntity(entityA);
+            ExprVector p0 = f->FaceGetPointExprs();
+            ExprVector n = f->FaceGetNormalExprs();
+            AddEq(l, (p.Minus(p0)).Dot(n), 0);
+            break;
+        }
+
         case PT_ON_LINE:
             if(workplane.v == Entity::FREE_IN_3D.v) {
                 Entity *ln = SS.GetEntity(entityA);
diff --git a/drawconstraint.cpp b/drawconstraint.cpp
index 7a6edbb..da00092 100644
--- a/drawconstraint.cpp
+++ b/drawconstraint.cpp
@@ -224,11 +224,25 @@ void Constraint::DrawOrGetDistance(Vector *labelPos) {
 
         case PT_ON_CIRCLE:
         case PT_ON_LINE:
+        case PT_ON_FACE:
         case PT_IN_PLANE: {
-            double s = 7/SS.GW.scale;
+            double s = 8/SS.GW.scale;
             Vector p = SS.GetEntity(ptA)->PointGetNum();
-            Vector r = gr.WithMagnitude(s);
-            Vector d = gu.WithMagnitude(s);
+            Vector r, d;
+            if(type == PT_ON_FACE) {
+                Vector n = SS.GetEntity(entityA)->FaceGetNormalNum();
+                r = n.Normal(0);
+                d = n.Normal(1);
+            } else if(type == PT_IN_PLANE) {
+                Entity *n = SS.GetEntity(entityA)->Normal();
+                r = n->NormalU();
+                d = n->NormalV();
+            } else {
+                r = gr;
+                d = gu;
+                s *= (6.0/8); // draw these a little smaller
+            }
+            r = r.WithMagnitude(s); d = d.WithMagnitude(s);
             LineDrawOrGetDistance(p.Plus (r).Plus (d), p.Plus (r).Minus(d));
             LineDrawOrGetDistance(p.Plus (r).Minus(d), p.Minus(r).Minus(d));
             LineDrawOrGetDistance(p.Minus(r).Minus(d), p.Minus(r).Plus (d));
diff --git a/dsc.h b/dsc.h
index 3782610..412947b 100644
--- a/dsc.h
+++ b/dsc.h
@@ -16,6 +16,7 @@ public:
     double w, vx, vy, vz;
 
     static Quaternion From(double w, double vx, double vy, double vz);
+    static Quaternion From(hParam w, hParam vx, hParam vy, hParam vz);
     static Quaternion From(Vector u, Vector v);
 
     Quaternion Plus(Quaternion b);
diff --git a/entity.cpp b/entity.cpp
index c64e681..0d1a873 100644
--- a/entity.cpp
+++ b/entity.cpp
@@ -574,6 +574,69 @@ Quaternion Entity::PointGetQuaternion(void) {
     return q;
 }
 
+bool Entity::IsFace(void) {
+    switch(type) {
+        case FACE_NORMAL_PT:
+        case FACE_XPROD:
+        case FACE_N_ROT_TRANS:
+            return true;
+        default:
+            return false;
+    }
+}
+
+ExprVector Entity::FaceGetNormalExprs(void) {
+    ExprVector r;
+    if(type == FACE_NORMAL_PT) {
+        r = ExprVector::From(numNormal.vx, numNormal.vy, numNormal.vz);
+    } else if(type == FACE_XPROD) {
+        ExprVector vc = ExprVector::From(param[0], param[1], param[2]);
+        ExprVector vn = ExprVector::From(numVector);
+        r = vc.Cross(vn);
+    } else if(type == FACE_N_ROT_TRANS) {
+        // The numerical normal vector gets the rotation
+        r = ExprVector::From(numNormal.vx, numNormal.vy, numNormal.vz);
+        ExprQuaternion q =
+            ExprQuaternion::From(param[3], param[4], param[5], param[6]);
+        r = q.Rotate(r);
+    } else oops();
+    return r;
+}
+
+Vector Entity::FaceGetNormalNum(void) {
+    Vector r;
+    if(type == FACE_NORMAL_PT) {
+        r = Vector::From(numNormal.vx, numNormal.vy, numNormal.vz);
+    } else if(type == FACE_XPROD) {
+        Vector vc = Vector::From(param[0], param[1], param[2]);
+        r = vc.Cross(numVector);
+    } else if(type == FACE_N_ROT_TRANS) {
+        // The numerical normal vector gets the rotation
+        r = Vector::From(numNormal.vx, numNormal.vy, numNormal.vz);
+        Quaternion q = Quaternion::From(param[3], param[4], param[5], param[6]);
+        r = q.Rotate(r);
+    } else oops();
+    return r;
+}
+
+ExprVector Entity::FaceGetPointExprs(void) {
+    ExprVector r;
+    if(type == FACE_NORMAL_PT) {
+        r = SS.GetEntity(point[0])->PointGetExprs();
+    } else if(type == FACE_XPROD) {
+        r = ExprVector::From(numPoint);
+    } else if(type == FACE_N_ROT_TRANS) {
+        // The numerical point gets the rotation and translation.
+        ExprVector trans = ExprVector::From(param[0], param[1], param[2]);
+        ExprQuaternion q =
+            ExprQuaternion::From(param[3], param[4], param[5], param[6]);
+        r = ExprVector::From(numPoint);
+        r = q.Rotate(r);
+        r = r.Plus(trans);
+    } else oops();
+    return r;
+}
+
 void Entity::LineDrawOrGetDistance(Vector a, Vector b) {
     if(dogd.drawing) {
         // glPolygonOffset works only on polys, not lines, so do it myself
@@ -890,6 +953,12 @@ void Entity::DrawOrGetDistance(int order) {
             break;
         }
 
+        case FACE_NORMAL_PT:
+        case FACE_XPROD:
+        case FACE_N_ROT_TRANS:
+            // Do nothing; these are drawn with the triangle mesh
+            break;
+
         default:
             oops();
     }
@@ -933,5 +1002,11 @@ void Entity::CalculateNumerical(void) {
     if(type == DISTANCE || type == DISTANCE_N_COPY) {
         actDistance = DistanceGetNum();
     }
+    if(IsFace()) {
+        ExprVector p = FaceGetPointExprs();
+        ExprVector n = FaceGetNormalExprs();
+        numPoint  = Vector::From(       p.x->Eval(), p.y->Eval(), p.z->Eval());
+        numNormal = Quaternion::From(0, n.x->Eval(), n.y->Eval(), n.z->Eval());
+    }
 }
 
diff --git a/expr.cpp b/expr.cpp
index eed0ac7..1904cb6 100644
--- a/expr.cpp
+++ b/expr.cpp
@@ -21,6 +21,14 @@ ExprVector ExprVector::From(hParam x, hParam y, hParam z) {
     return ve;
 }
 
+ExprVector ExprVector::From(double x, double y, double z) {
+    ExprVector ve;
+    ve.x = Expr::From(x);
+    ve.y = Expr::From(y);
+    ve.z = Expr::From(z);
+    return ve;
+}
+
 ExprVector ExprVector::Minus(ExprVector b) {
     ExprVector r;
     r.x = x->Minus(b.x);
@@ -236,6 +244,15 @@ int Expr::Children(void) {
     }
 }
 
+int Expr::Nodes(void) {
+    switch(Children()) {
+        case 0: return 1;
+        case 1: return 1 + a->Nodes();
+        case 2: return 1 + a->Nodes() + b->Nodes();
+        default: oops();
+    }
+}
+
 Expr *Expr::DeepCopy(void) {
     Expr *n = AllocExpr();
     *n = *this;
diff --git a/expr.h b/expr.h
index cb8ebf8..1d68e77 100644
--- a/expr.h
+++ b/expr.h
@@ -92,6 +92,8 @@ public:
     Expr *DeepCopy(void);
     // number of child nodes: 0 (e.g. constant), 1 (sqrt), or 2 (+)
     int Children(void);
+    // total number of nodes in the tree
+    int Nodes(void);
 
     // Make a copy, with the parameters (usually referenced by hParam)
     // resolved to pointers to the actual value. This speeds things up
@@ -125,6 +127,7 @@ public:
     static ExprVector From(Expr *x, Expr *y, Expr *z);
     static ExprVector From(Vector vn);
     static ExprVector From(hParam x, hParam y, hParam z);
+    static ExprVector From(double x, double y, double z);
 
     ExprVector Plus(ExprVector b);
     ExprVector Minus(ExprVector b);
diff --git a/glhelper.cpp b/glhelper.cpp
index b5aa401..1f1a7a3 100644
--- a/glhelper.cpp
+++ b/glhelper.cpp
@@ -111,7 +111,7 @@ void glxColor4d(double r, double g, double b, double a)
     if(!ColorLocked) glColor4d(r, g, b, a);
 }
 
-void glxFillMesh(bool useModelColor, SMesh *m)
+void glxFillMesh(int specColor, SMesh *m, DWORD h, DWORD s1, DWORD s2)
 {
     glEnable(GL_NORMALIZE);
     int prevColor = -1;
@@ -121,8 +121,19 @@ void glxFillMesh(bool useModelColor, SMesh *m)
         Vector n = tr->Normal();
         glNormal3d(n.x, n.y, n.z);
 
-        int color = tr->meta.color;
-        if(useModelColor && color != prevColor) {
+        int color;
+        if((s1 != 0 && tr->meta.face == s1) || 
+           (s2 != 0 && tr->meta.face == s2))
+        {
+            color = RGB(200, 0, 0);
+        } else if(h != 0 && tr->meta.face == h) {
+            color = RGB(200, 200, 0);
+        } else if(specColor < 0) {
+            color = tr->meta.color;
+        } else {
+            color = specColor;
+        }
+        if(color != prevColor) {
             GLfloat mpf[] = { ((color >>  0) & 0xff) / 255.0f,
                               ((color >>  8) & 0xff) / 255.0f,
                               ((color >> 16) & 0xff) / 255.0f, 1.0 };
diff --git a/graphicswin.cpp b/graphicswin.cpp
index a65f2aa..2b42023 100644
--- a/graphicswin.cpp
+++ b/graphicswin.cpp
@@ -745,6 +745,15 @@ void GraphicsWindow::HitTestMakeSelection(Point2d mp) {
         }
     }
 
+    // Faces, from the triangle mesh; these are lowest priority
+    if(s.constraint.v == 0 && s.entity.v == 0 && (showMesh || showShaded)) {
+        SMesh *m = &((SS.GetGroup(activeGroup))->mesh);
+        DWORD v = m->FirstIntersectionWith(mp);
+        if(v) {
+            s.entity.v = v;
+        }
+    }
+
     if(!s.Equals(&hover)) {
         hover = s;
         InvalidateGraphics();
@@ -804,6 +813,11 @@ void GraphicsWindow::GroupSelection(void) {
                 gs.vector[(gs.vectors)++] = s->entity;
             }
 
+            // Faces (which are special, associated/drawn with triangles)
+            if(e->IsFace()) {
+                gs.face[(gs.faces)++] = s->entity;
+            }
+
             // And some aux counts too
             switch(e->type) {
                 case Entity::WORKPLANE:     (gs.workplanes)++; break;
diff --git a/mesh.cpp b/mesh.cpp
index cdc5cbd..6e0b560 100644
--- a/mesh.cpp
+++ b/mesh.cpp
@@ -235,6 +235,35 @@ void SMesh::MakeFromDifference(SMesh *a, SMesh *b) {
     dbp("tris = %d", l.n);
 }
 
+DWORD SMesh::FirstIntersectionWith(Point2d mp) {
+    Vector gu = SS.GW.projRight, gv = SS.GW.projUp;
+    Vector gn = (gu.Cross(gv)).WithMagnitude(1);
+
+    Vector p0 = gu.ScaledBy(mp.x/SS.GW.scale).Plus(
+                gv.ScaledBy(mp.y/SS.GW.scale));
+    p0 = p0.Minus(SS.GW.offset);
+
+    double maxT = -1e12;
+    DWORD face = 0;
+
+    int i;
+    for(i = 0; i < l.n; i++) {
+        STriangle *tr = &(l.elem[i]);
+        Vector n = tr->Normal();
+        if(n.Dot(gn) < LENGTH_EPS) continue; // back-facing or on edge
+
+        if(tr->ContainsPointProjd(gn, p0)) {
+            // Let our line have the form r(t) = p0 + gn*t
+            double t = (n.Dot((tr->a).Minus(p0)))/(n.Dot(gn));
+            if(t > maxT) {
+                maxT = t;
+                face = tr->meta.face;
+            }
+        }
+    }
+    return face;
+}
+
 SBsp2 *SBsp2::Alloc(void) { return (SBsp2 *)AllocTemporary(sizeof(SBsp2)); }
 SBsp3 *SBsp3::Alloc(void) { return (SBsp3 *)AllocTemporary(sizeof(SBsp3)); }
 
diff --git a/polygon.cpp b/polygon.cpp
index e54d771..699b581 100644
--- a/polygon.cpp
+++ b/polygon.cpp
@@ -6,9 +6,12 @@ Vector STriangle::Normal(void) {
 }
 
 bool STriangle::ContainsPoint(Vector p) {
+    Vector n = Normal();
+    return ContainsPointProjd(n.WithMagnitude(1), p);
+}
+
+bool STriangle::ContainsPointProjd(Vector n, Vector p) {
     Vector ab = b.Minus(a), bc = c.Minus(b), ca = a.Minus(c);
-    Vector n = ab.Cross(bc);
-    n = n.WithMagnitude(1);
 
     Vector no_ab = n.Cross(ab);
     if(no_ab.Dot(p) < no_ab.Dot(a) - LENGTH_EPS) return false;
diff --git a/polygon.h b/polygon.h
index c29eca5..743c3cd 100644
--- a/polygon.h
+++ b/polygon.h
@@ -114,6 +114,7 @@ public:
     static STriangle From(STriMeta meta, Vector a, Vector b, Vector c);
     Vector Normal(void);
     bool ContainsPoint(Vector p);
+    bool ContainsPointProjd(Vector n, Vector p);
 };
 
 class SBsp2 {
@@ -190,6 +191,8 @@ public:
     void AddAgainstBsp(SMesh *srcm, SBsp3 *bsp3);
     void MakeFromUnion(SMesh *a, SMesh *b);
     void MakeFromDifference(SMesh *a, SMesh *b);
+
+    DWORD FirstIntersectionWith(Point2d mp);
 };
 
 // A linked list of triangles
diff --git a/sketch.cpp b/sketch.cpp
index 225e42c..6482e32 100644
--- a/sketch.cpp
+++ b/sketch.cpp
@@ -10,6 +10,8 @@ const hRequest Request::HREQUEST_REFERENCE_XY = { 1 };
 const hRequest Request::HREQUEST_REFERENCE_YZ = { 2 };
 const hRequest Request::HREQUEST_REFERENCE_ZX = { 3 };
 
+#define gs (SS.GW.gs)
+
 void Group::AddParam(IdList<Param,hParam> *param, hParam hp, double v) {
     Param pa;
     memset(&pa, 0, sizeof(pa));
@@ -30,7 +32,6 @@ void Group::MenuGroup(int id) {
     }
 
     SS.GW.GroupSelection();
-#define gs (SS.GW.gs)
 
     switch(id) {
         case GraphicsWindow::MNU_GROUP_3D:
@@ -214,7 +215,7 @@ void Group::Generate(IdList<Entity,hEntity> *entity,
             break;
         }
 
-        case EXTRUDE:
+        case EXTRUDE: {
             AddParam(param, h.param(0), gn.x);
             AddParam(param, h.param(1), gn.y);
             AddParam(param, h.param(2), gn.z);
@@ -224,10 +225,16 @@ void Group::Generate(IdList<Entity,hEntity> *entity,
             } else if(subtype == TWO_SIDED) {
                 ai = -1; af = 1;
             } else oops();
+
+            // Get some arbitrary point in the sketch, that will be used
+            // as a reference when defining top and bottom faces.
+            hEntity pt = { 0 };
             for(i = 0; i < entity->n; i++) {
                 Entity *e = &(entity->elem[i]);
                 if(e->group.v != opA.v) continue;
 
+                if(e->IsPoint()) pt = e->h;
+
                 e->CalculateNumerical();
                 hEntity he = e->h; e = NULL;
                 // As soon as I call CopyEntity, e may become invalid! That
@@ -242,7 +249,11 @@ void Group::Generate(IdList<Entity,hEntity> *entity,
                     true, false);
                 MakeExtrusionLines(he);
             }
+            // Remapped versions of that arbitrary point will be used to
+            // provide points on the plane faces.
+            MakeExtrusionTopBottomFaces(pt);
             break;
+        }
 
         case TRANSLATE: {
             // The translation vector
@@ -386,16 +397,54 @@ hEntity Group::Remap(hEntity in, int copyNumber) {
 
 void Group::MakeExtrusionLines(hEntity in) {
     Entity *ep = SS.GetEntity(in);
-    if(!(ep->IsPoint())) return;
 
     Entity en;
-    memset(&en, 0, sizeof(en));
-    en.point[0] = Remap(ep->h, REMAP_TOP);
-    en.point[1] = Remap(ep->h, REMAP_BOTTOM);
+    ZERO(&en);
+    if(ep->IsPoint()) {
+        // A point gets extruded to form a line segment
+        en.point[0] = Remap(ep->h, REMAP_TOP);
+        en.point[1] = Remap(ep->h, REMAP_BOTTOM);
+        en.group = h;
+        en.h = Remap(ep->h, REMAP_PT_TO_LINE);
+        en.type = Entity::LINE_SEGMENT;
+        SS.entity.Add(&en);
+    } else if(ep->type == Entity::LINE_SEGMENT) {
+        // A line gets extruded to form a plane face; an endpoint of the
+        // original line is a point in the plane, and the line is in the plane.
+        Vector a = SS.GetEntity(ep->point[0])->PointGetNum();
+        Vector b = SS.GetEntity(ep->point[1])->PointGetNum();
+        Vector ab = b.Minus(a);
+
+        en.param[0] = h.param(0);
+        en.param[1] = h.param(1);
+        en.param[2] = h.param(2);
+        en.numPoint = a;
+        en.numVector = ab;
+
+        en.group = h;
+        en.h = Remap(ep->h, REMAP_LINE_TO_FACE);
+        en.type = Entity::FACE_XPROD;
+        SS.entity.Add(&en);
+    }
+}
+
+void Group::MakeExtrusionTopBottomFaces(hEntity pt) {
+    if(pt.v == 0) return;
+    Group *src = SS.GetGroup(opA);
+    Vector n = src->poly.normal;
+
+    Entity en;
+    ZERO(&en);
+    en.type = Entity::FACE_NORMAL_PT;
     en.group = h;
-    en.h = Remap(ep->h, 10);
-    en.type = Entity::LINE_SEGMENT;
-    // And then this line segment gets added
+
+    en.numNormal = Quaternion::From(0, n.x, n.y, n.z);
+    en.point[0] = Remap(pt, REMAP_TOP);
+    en.h = Remap(Entity::NO_ENTITY, REMAP_TOP);
+    SS.entity.Add(&en);
+
+    en.point[0] = Remap(pt, REMAP_BOTTOM);
+    en.h = Remap(Entity::NO_ENTITY, REMAP_BOTTOM);
     SS.entity.Add(&en);
 }
 
@@ -498,6 +547,23 @@ void Group::CopyEntity(Entity *ep, int timesApplied, int remap,
             en.numDistance = ep->actDistance;
             break;
 
+        case Entity::FACE_NORMAL_PT:
+        case Entity::FACE_XPROD:
+        case Entity::FACE_N_ROT_TRANS:
+            if(asTrans || asAxisAngle) return;
+
+            en.type = Entity::FACE_N_ROT_TRANS;
+            en.param[0] = dx;
+            en.param[1] = dy;
+            en.param[2] = dz;
+            en.param[3] = qw;
+            en.param[4] = qvx;
+            en.param[5] = qvy;
+            en.param[6] = qvz;
+            en.numPoint = ep->numPoint;
+            en.numNormal = ep->numNormal;
+            break;
+
         default:
             oops();
     }
@@ -526,8 +592,8 @@ void Group::TagEdgesFromLineSegments(SEdgeList *el) {
         
         for(j = 0; j < el->l.n; j++) {
             SEdge *se = &(el->l.elem[j]);
-            if((p0.Equals(se->a) && p1.Equals(se->b))) se->tag = 1;
-            if((p0.Equals(se->b) && p1.Equals(se->a))) se->tag = 1;
+            if((p0.Equals(se->a) && p1.Equals(se->b))) se->tag = e->h.v;
+            if((p0.Equals(se->b) && p1.Equals(se->a))) se->tag = e->h.v;
         }
     }
 }
@@ -583,6 +649,7 @@ void Group::MakePolygons(void) {
         STriMeta meta = { 0, color };
 
         // Do the bottom; that has normal pointing opposite from translate
+        meta.face = Remap(Entity::NO_ENTITY, REMAP_BOTTOM).v;
         for(i = 0; i < srcm.l.n; i++) {
             STriangle *st = &(srcm.l.elem[i]);
             Vector at = (st->a).Plus(tbot), 
@@ -595,6 +662,7 @@ void Group::MakePolygons(void) {
             }
         }
         // And the top; that has the normal pointing the same dir as translate
+        meta.face = Remap(Entity::NO_ENTITY, REMAP_TOP).v;
         for(i = 0; i < srcm.l.n; i++) {
             STriangle *st = &(srcm.l.elem[i]);
             Vector at = (st->a).Plus(ttop), 
@@ -618,6 +686,15 @@ void Group::MakePolygons(void) {
             SEdge *edge = &(edges.l.elem[i]);
             Vector abot = (edge->a).Plus(tbot), bbot = (edge->b).Plus(tbot);
             Vector atop = (edge->a).Plus(ttop), btop = (edge->b).Plus(ttop);
+            // We tagged the edges that came from line segments; their
+            // triangles should be associated with that plane face.
+            if(edge->tag) {
+                hEntity hl = { edge->tag };
+                hEntity hf = Remap(hl, REMAP_LINE_TO_FACE);
+                meta.face = hf.v;
+            } else {
+                meta.face = 0;
+            }
             if(flipBottom) {
                 outm.AddTriangle(meta, bbot, abot, atop);
                 outm.AddTriangle(meta, bbot, atop, btop);
@@ -641,6 +718,11 @@ void Group::MakePolygons(void) {
 
         for(int i = 0; i < impMesh.l.n; i++) {
             STriangle st = impMesh.l.elem[i];
+
+            if(st.meta.face != 0) {
+                hEntity he = { st.meta.face };
+                st.meta.face = Remap(he, 0).v;
+            }
             st.a = q.Rotate(st.a).Plus(offset);
             st.b = q.Rotate(st.b).Plus(offset);
             st.c = q.Rotate(st.c).Plus(offset);
@@ -665,21 +747,30 @@ void Group::Draw(void) {
     // Show this even if the group is not visible. It's already possible
     // to show or hide just this with the "show solids" flag.
 
-    bool useModelColor;
+    int specColor;
     if(type != EXTRUDE && type != IMPORTED) {
-        GLfloat mpf[] = { 0.1f, 0.1f, 0.1f, 1.0 };
-        glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, mpf);
-        useModelColor = false;
+        specColor = RGB(25, 25, 25); // force the color to something dim
     } else {
-        useModelColor = true;
+        specColor = -1; // use the model color
     }
     // The back faces are drawn in red; should never seem them, since we
     // draw closed shells, so that's a debugging aid.
     GLfloat mpb[] = { 1.0f, 0.1f, 0.1f, 1.0 };
     glMaterialfv(GL_BACK, GL_AMBIENT_AND_DIFFUSE, mpb);
 
+    // When we fill the mesh, we need to know which triangles are selected
+    // or hovered, in order to draw them differently.
+    DWORD mh = 0, ms1 = 0, ms2 = 0;
+    hEntity he = SS.GW.hover.entity;
+    if(he.v != 0 && SS.GetEntity(he)->IsFace()) {
+        mh = he.v;
+    }
+    SS.GW.GroupSelection();
+    if(gs.faces > 0) ms1 = gs.face[0].v;
+    if(gs.faces > 1) ms2 = gs.face[1].v;
+
     glEnable(GL_LIGHTING);
-    if(SS.GW.showShaded) glxFillMesh(useModelColor, &mesh);
+    if(SS.GW.showShaded) glxFillMesh(specColor, &mesh, mh, ms1, ms2);
     glDisable(GL_LIGHTING);
 
     if(SS.GW.showMesh) glxDebugMesh(&mesh);
diff --git a/sketch.h b/sketch.h
index 86e2bb1..27a966f 100644
--- a/sketch.h
+++ b/sketch.h
@@ -148,8 +148,11 @@ public:
     static const int REMAP_LAST         = 1000;
     static const int REMAP_TOP          = 1001;
     static const int REMAP_BOTTOM       = 1002;
+    static const int REMAP_PT_TO_LINE   = 1003;
+    static const int REMAP_LINE_TO_FACE = 1004;
     hEntity Remap(hEntity in, int copyNumber);
     void MakeExtrusionLines(hEntity in);
+    void MakeExtrusionTopBottomFaces(hEntity pt);
     void TagEdgesFromLineSegments(SEdgeList *sle);
     void CopyEntity(Entity *ep, int timesApplied, int remap,
                     hParam dx, hParam dy, hParam dz,
@@ -232,9 +235,9 @@ public:
     static const int DISTANCE               =  4000;
     static const int DISTANCE_N_COPY        =  4001;
 
-    static const int FACE_N_COPY            =  5000;
-    static const int FACE_N_TRANS           =  5001;
-    static const int FACE_N_XPROD           =  5002;
+    static const int FACE_NORMAL_PT         =  5000;
+    static const int FACE_XPROD             =  5001;
+    static const int FACE_N_ROT_TRANS       =  5002;
 
 
     static const int WORKPLANE              = 10000;
@@ -258,6 +261,8 @@ public:
     Vector      numPoint;
     Quaternion  numNormal;
     double      numDistance;
+    // and a bit more state that the faces need
+    Vector      numVector;
 
     // All points/normals/distances have their numerical value; this is
     // a convenience, to simplify the import/assembly code, so that the
@@ -297,6 +302,11 @@ public:
     Vector WorkplaneGetOffset(void);
     Entity *Normal(void);
 
+    bool IsFace(void);
+    ExprVector FaceGetNormalExprs(void);
+    Vector FaceGetNormalNum(void);
+    ExprVector FaceGetPointExprs(void);
+
     bool IsPoint(void);
     // Applies for any of the point types
     Vector PointGetNum(void);
diff --git a/solvespace.h b/solvespace.h
index 930ee18..65fc12e 100644
--- a/solvespace.h
+++ b/solvespace.h
@@ -104,7 +104,7 @@ void glxVertex3v(Vector u);
 typedef void GLX_CALLBACK glxCallbackFptr(void);
 void glxTesselatePolygon(GLUtesselator *gt, SPolygon *p);
 void glxFillPolygon(SPolygon *p);
-void glxFillMesh(bool useModelColor, SMesh *m);
+void glxFillMesh(int color, SMesh *m, DWORD h, DWORD s1, DWORD s2);
 void glxDebugPolygon(SPolygon *p);
 void glxDebugEdgeList(SEdgeList *l);
 void glxDebugMesh(SMesh *m);
diff --git a/util.cpp b/util.cpp
index a89482e..801b6c2 100644
--- a/util.cpp
+++ b/util.cpp
@@ -32,6 +32,15 @@ Quaternion Quaternion::From(double w, double vx, double vy, double vz) {
     return q;
 }
 
+Quaternion Quaternion::From(hParam w, hParam vx, hParam vy, hParam vz) {
+    Quaternion q;
+    q.w  = SS.GetParam(w )->val;
+    q.vx = SS.GetParam(vx)->val;
+    q.vy = SS.GetParam(vy)->val;
+    q.vz = SS.GetParam(vz)->val;
+    return q;
+}
+
 Quaternion Quaternion::From(Vector u, Vector v)
 {
     Vector n = u.Cross(v);