diff --git a/drawentity.cpp b/drawentity.cpp
index 2c23168..5dda1e7 100644
--- a/drawentity.cpp
+++ b/drawentity.cpp
@@ -48,6 +48,31 @@ void Entity::DrawAll(void) {
             if(e->forceHidden) continue;
 
             Vector v = e->PointGetNum();
+
+            bool free = false;
+            if(e->type == POINT_IN_3D) {
+                Param *px = SS.GetParam(e->param[0]),
+                      *py = SS.GetParam(e->param[1]),
+                      *pz = SS.GetParam(e->param[2]);
+
+                free = (px->free) || (py->free) || (pz->free);
+            } else if(e->type == POINT_IN_2D) {
+                Param *pu = SS.GetParam(e->param[0]),
+                      *pv = SS.GetParam(e->param[1]);
+
+                free = (pu->free) || (pv->free);
+            }
+            if(free) {
+                Vector re = r.ScaledBy(2.5), de = d.ScaledBy(2.5);
+
+                glxColor3d(0, 1.0, 1.0);
+                glxVertex3v(v.Plus (re).Plus (de));
+                glxVertex3v(v.Plus (re).Minus(de));
+                glxVertex3v(v.Minus(re).Minus(de));
+                glxVertex3v(v.Minus(re).Plus (de));
+                glxColor3d(0, 0.8, 0);
+            }
+
             glxVertex3v(v.Plus (r).Plus (d));
             glxVertex3v(v.Plus (r).Minus(d));
             glxVertex3v(v.Minus(r).Minus(d));
diff --git a/generate.cpp b/generate.cpp
index a8376cc..e8d8b9f 100644
--- a/generate.cpp
+++ b/generate.cpp
@@ -156,7 +156,7 @@ void SolveSpace::GenerateAll(void) {
     }
 }
 
-void SolveSpace::GenerateAll(int first, int last) {
+void SolveSpace::GenerateAll(int first, int last, bool andFindFree) {
     int i, j;
 
     // Remove any requests or constraints that refer to a nonexistent
@@ -221,7 +221,7 @@ void SolveSpace::GenerateAll(int first, int last) {
                 }
                 // The group falls inside the range, so really solve it,
                 // and then regenerate the mesh based on the solved stuff.
-                SolveGroup(g->h);
+                SolveGroup(g->h, andFindFree);
                 g->GeneratePolygon();
                 g->GenerateMesh();
                 g->clean = true;
@@ -341,7 +341,7 @@ void SolveSpace::ForceReferences(void) {
     }
 }
 
-void SolveSpace::SolveGroup(hGroup hg) {
+void SolveSpace::SolveGroup(hGroup hg, bool andFindFree) {
     int i;
     // Clear out the system to be solved.
     sys.entity.Clear();
@@ -364,7 +364,7 @@ void SolveSpace::SolveGroup(hGroup hg) {
         p->val = GetParam(p->h)->val;
     }
 
-    sys.Solve(g);
+    sys.Solve(g, andFindFree);
     FreeAllTemporary();
 }
 
diff --git a/graphicswin.cpp b/graphicswin.cpp
index ec617b3..e694997 100644
--- a/graphicswin.cpp
+++ b/graphicswin.cpp
@@ -40,7 +40,7 @@ const GraphicsWindow::MenuEntry GraphicsWindow::menu[] = {
 { 1, "Zoom To &Fit\tF",                     MNU_ZOOM_TO_FIT,    'F',    mView },
 { 1,  NULL,                                 0,                          NULL  },
 { 1, "Nearest &Ortho View\tF1",             MNU_NEAREST_ORTHO,  F(1),   mView },
-{ 1, "Nearest &Iso View\tF2",               MNU_NEAREST_ISO,    F(2),   mView },
+{ 1, "Nearest &Isometric View\tF2",         MNU_NEAREST_ISO,    F(2),   mView },
 { 1,  NULL,                                 0,                          NULL  },
 { 1, "Show Text &Window\tTab",              MNU_SHOW_TEXT_WND,  '\t',   mView },
 { 1, "Show &Toolbar",                       MNU_SHOW_TOOLBAR,   0,      mView },
@@ -102,7 +102,9 @@ const GraphicsWindow::MenuEntry GraphicsWindow::menu[] = {
 { 1, "Comment\t;",                          MNU_COMMENT,        ';',    mCon  },
 
 { 0, "&Analyze",                            0,                          NULL  },
-{ 1, "Measure &Volume",                     MNU_VOLUME,         0,      mAna  },
+{ 1, "Measure &Volume\tCtrl+Shift+V",       MNU_VOLUME,         'V'|S|C,mAna  },
+{ 1, NULL,                                  0,                          NULL  },
+{ 1, "Show Degrees of &Freedom\tCtrl+Shift+F", MNU_SHOW_DOF,    'F'|S|C,mAna  },
 { 1, NULL,                                  0,                          NULL  },
 { 1, "&Trace Point\tCtrl+Shift+T",          MNU_TRACE_PT,       'T'|S|C,mAna  },
 { 1, "&Stop Tracing...\tCtrl+Shift+S",      MNU_STOP_TRACING,   'S'|S|C,mAna  },
diff --git a/sketch.h b/sketch.h
index cd2fedb..bd77362 100644
--- a/sketch.h
+++ b/sketch.h
@@ -425,6 +425,7 @@ public:
 
     double      val;
     bool        known;
+    bool        free;
 
     // Used only in the solver
     hParam      substd;
diff --git a/solvespace.cpp b/solvespace.cpp
index 656a126..1070ef4 100644
--- a/solvespace.cpp
+++ b/solvespace.cpp
@@ -453,6 +453,12 @@ void SolveSpace::MenuAnalyze(int id) {
             break;
         }
 
+        case GraphicsWindow::MNU_SHOW_DOF:
+            // This works like a normal solve, except that it calculates
+            // which variables are free/bound at the same time.
+            SS.GenerateAll(0, INT_MAX, true);
+            break;
+
         case GraphicsWindow::MNU_TRACE_PT:
             if(gs.points == 1 && gs.n == 1) {
                 SS.traced.point = gs.point[0];
diff --git a/solvespace.h b/solvespace.h
index 386522e..a38864b 100644
--- a/solvespace.h
+++ b/solvespace.h
@@ -192,6 +192,7 @@ public:
     // In general, the tag indicates the subsys that a variable/equation
     // has been assigned to; these are exceptions for variables:
     static const int VAR_SUBSTITUTED      = 10000;
+    static const int VAR_DOF_TEST         = 10001;
     // and for equations:
     static const int EQ_SUBSTITUTED       = 20000;
 
@@ -240,7 +241,7 @@ public:
     static bool IsDragged(hParam p);
 
     bool NewtonSolve(int tag);
-    void Solve(Group *g);
+    void Solve(Group *g, bool andFindFree);
 };
 
 class TtfFont {
@@ -466,8 +467,8 @@ public:
     bool PruneConstraints(hGroup hg);
 
     void GenerateAll(void);
-    void GenerateAll(int first, int last);
-    void SolveGroup(hGroup hg);
+    void GenerateAll(int first, int last, bool andFindFree=false);
+    void SolveGroup(hGroup hg, bool andFindFree);
     void ForceReferences(void);
 
     bool AllGroupsOkay(void);
diff --git a/system.cpp b/system.cpp
index 1e36e32..5757a56 100644
--- a/system.cpp
+++ b/system.cpp
@@ -398,7 +398,7 @@ void System::FindWhichToRemoveToFixJacobian(Group *g) {
     }
 }
 
-void System::Solve(Group *g) {
+void System::Solve(Group *g, bool andFindFree) {
     g->solved.remove.Clear();
 
     WriteEquationsExceptFor(Constraint::NO_CONSTRAINT, g->h);
@@ -469,6 +469,27 @@ void System::Solve(Group *g) {
         goto didnt_converge;
     }
 
+    // If requested, find all the free (unbound) variables. This might be
+    // more than the number of degrees of freedom. Don't always do this,
+    // because the display would get annoying and it's slow.
+    for(i = 0; i < param.n; i++) {
+        Param *p = &(param.elem[i]);
+        p->free = false;
+
+        if(andFindFree) {
+            if(p->tag == 0) {
+                p->tag = VAR_DOF_TEST;
+                WriteJacobian(0);
+                EvalJacobian();
+                rank = CalculateRank();
+                if(rank == mat.m) {
+                    p->free = true;
+                }
+                p->tag = 0;
+            }
+        }
+    }
+
     // System solved correctly, so write the new values back in to the
     // main parameter table.
     for(i = 0; i < param.n; i++) {
@@ -482,6 +503,7 @@ void System::Solve(Group *g) {
         Param *pp = SS.GetParam(p->h);
         pp->val = val;
         pp->known = true;
+        pp->free = p->free;
     }
     if(g->solved.how != Group::SOLVED_OKAY) {
         g->solved.how = Group::SOLVED_OKAY;
diff --git a/ui.h b/ui.h
index 0f66a74..9bda2e1 100644
--- a/ui.h
+++ b/ui.h
@@ -238,6 +238,7 @@ public:
         MNU_COMMENT,
         // Analyze
         MNU_VOLUME,
+        MNU_SHOW_DOF,
         MNU_TRACE_PT,
         MNU_STOP_TRACING,
         MNU_STEP_DIM,