diff --git a/geom-exp.cpp b/geom-exp.cpp
index 10ec8bd2..96221d2a 100644
--- a/geom-exp.cpp
+++ b/geom-exp.cpp
@@ -709,7 +709,24 @@ EX void showEuclideanMenu() {
       });
     }
   
-  if(euwrap || geometry == gFieldQuotient || cryst || archimedean || (euclid && WDIM == 3)) {
+  else if(geometry == gRotSpace) {
+    constexpr auto& r = rots::underlying_scale;
+    dialog::addSelItem(XLAT("view the underlying geometry"), r > 0 ? fts(r)+"x" : "NO", '4');
+    dialog::add_action([] {
+      dialog::editNumber(r, 0, 1, 0.05, 0.25, XLAT("view the underlying geometry"),
+        XLAT(
+          "The space you are currently in the space of rotations of the underlying hyperbolic or spherical geometry. "
+          "This option lets you see the underlying space. Lands and some walls (e.g. in the Graveyard) are based on "
+          "the respective features in the underlying world, but details such as monsters or items are ignored."
+          )
+        );
+      dialog::bound_low(0);
+      dialog::bound_up(1);
+      dialog::extra_options = [] () { rots::draw_underlying(true); };
+      });
+    }
+  
+  else if(euwrap || geometry == gFieldQuotient || cryst || archimedean || (euclid && WDIM == 3)) {
     dialog::addItem(XLAT("advanced parameters"), '4');
     dialog::add_action([] {
       if(0); 
diff --git a/graph.cpp b/graph.cpp
index 9db348e2..db18e529 100644
--- a/graph.cpp
+++ b/graph.cpp
@@ -7531,6 +7531,8 @@ EX bool dronemode;
 
 purehookset hooks_calcparam;
 
+EX int corner_centering;
+
 EX void calcparam() {
 
   DEBBI(DF_GRAPH, ("calc param"));
@@ -7571,11 +7573,21 @@ EX void calcparam() {
   if(GDIM == 3 && in_perspective()) cd->radius = cd->scrsize;
   realradius = min(realradius, cd->radius);
   
+  ld aradius = sphere ? cd->radius / (vid.alpha - 1) : cd->radius;
+  
   if(dronemode) { cd->ycenter -= cd->radius; cd->ycenter += vid.fsize/2; cd->ycenter += vid.fsize/2; cd->radius *= 2; }
   
+  if(corner_centering) {
+    cd->ycenter = cd->ytop + cd->ysize - vid.fsize - aradius;
+    if(corner_centering == 1)
+      cd->xcenter = cd->xtop + vid.fsize + aradius;
+    if(corner_centering == 2)
+      cd->xcenter = cd->xtop + cd->xsize - vid.fsize - aradius;
+    }
+
   cd->xcenter += cd->scrsize * vid.xposition;
   cd->ycenter += cd->scrsize * vid.yposition;
-
+  
   cd->tanfov = tan(vid.fov * degree / 2);
   
   if(pmodel) 
diff --git a/hud.cpp b/hud.cpp
index 181a85c4..9e4e96e8 100644
--- a/hud.cpp
+++ b/hud.cpp
@@ -481,6 +481,10 @@ EX void drawStats() {
   first_cell_to_draw = true;
   bool h = hide_player();
 
+  bool cornermode = (vid.xres > vid.yres * 85/100 && vid.yres > vid.xres * 85/100);
+  
+  if(geometry == gRotSpace) rots::draw_underlying(!cornermode);
+  
   {
   dynamicval<eModel> pm(pmodel, flat_model());
   glClear(GL_DEPTH_BUFFER_BIT);
@@ -492,9 +496,7 @@ EX void drawStats() {
   if(prod) vid.alpha = 30, vid.scale = 30;
 
   calcparam();
-  
-  bool cornermode = (vid.xres > vid.yres * 85/100 && vid.yres > vid.xres * 85/100);
-  
+
   if(vid.radarsize > 0 && h)
   #if CAP_RACING
     if(!racing::on)
diff --git a/nonisotropic.cpp b/nonisotropic.cpp
index 94eefd9c..fa3c6139 100644
--- a/nonisotropic.cpp
+++ b/nonisotropic.cpp
@@ -1217,6 +1217,89 @@ EX namespace rots {
       }
     };
 
+  /** reinterpret the given point of rotspace as a rotation matrix in the underlying geometry */
+  EX transmatrix qtm(hyperpoint h) {
+    if(hyperbolic) {
+      hyperpoint k = slr::to_phigans(h);
+      ld z = k[2]; k[2] = 0;
+      ld r = hypot_d(2, k);
+      // k[1] = -k[1];
+      k[0] = -k[0];
+      if(r) k = tangent_length(k, asinh(r) * 2);
+      return spin(-z * 2) * rgpushxto0(direct_exp(k, 0));
+      }
+
+    double sq0 = h[0]*h[0];
+    double sq1 = h[1]*h[1];
+    double sq2 = h[2]*h[2];
+    double sq3 = h[3]*h[3];
+    
+    transmatrix M;  
+  
+    M[0][0] =  sq0 - sq1 - sq2 + sq3;
+    M[1][1] = -sq0 + sq1 - sq2 + sq3;
+    M[2][2] = -sq0 - sq1 + sq2 + sq3;
+    
+    double tmp1 = h[0]*h[1];
+    double tmp2 = h[2]*h[3];
+    M[0][1] = -2 * (tmp1 + tmp2);
+    M[1][0] = -2 * (tmp1 - tmp2);
+    
+    tmp1 = h[0]*h[2];
+    tmp2 = h[1]*h[3];
+    M[0][2] = 2 * (tmp1 - tmp2);
+    M[2][0] = 2 * (tmp1 + tmp2);
+
+    tmp1 = h[1]*h[2];
+    tmp2 = h[0]*h[3];
+    M[1][2] = -2 * (tmp1 + tmp2);
+    M[2][1] = -2 * (tmp1 - tmp2);
+  
+    return M;
+    }
+  
+  EX ld underlying_scale = 0;
+  
+  EX void draw_underlying(bool cornermode) {
+    if(underlying_scale <= 0) return;
+    ld d = hybrid::current_view_level;
+    d *= cgi.plevel;
+    transmatrix T = rots::uzpush(-d) * spin(-2*d);
+  
+    if(det(T) < 0) T = centralsym * T;
+  
+    hyperpoint h = inverse(View * spin(master_to_c7_angle()) * T) * C0;
+    
+    auto g = std::move(gmatrix);
+    auto g0 = std::move(gmatrix0);
+  
+    hybrid::in_underlying_map([&] {
+      cgi.require_shapes();
+      dynamicval<int> pcc(corner_centering, cornermode ? 1 : 2);
+      dynamicval<bool> pf(playerfound, true);
+      dynamicval<cellwalker> m5(centerover, viewctr.at->c7);
+      dynamicval<transmatrix> m2(View, ypush(0) * qtm(h));
+      dynamicval<transmatrix> m3(playerV, Id);
+      dynamicval<transmatrix> m4(actual_view_transform, Id);
+      dynamicval<eModel> pm(pmodel, mdDisk);
+      dynamicval<ld> pss(vid.scale, (sphere ? 10 : 1) * underlying_scale);
+      dynamicval<ld> psa(vid.alpha, sphere ? 10 : 1);
+      dynamicval<hrmap*> p(hybrid::pmap, NULL);
+      dynamicval<int> psr(sightrange_bonus, 0);
+      calcparam();
+      reset_projection(); current_display->set_all(0);
+      ptds.clear();
+      drawthemap();
+      drawqueue();
+      displaychr(current_display->xcenter, current_display->ycenter, 0, 24, '+', 0xFFFFFFFF);
+      glflush();
+      });
+    gmatrix = std::move(g);
+    gmatrix0 = std::move(g0);
+    calcparam();
+    reset_projection(); current_display->set_all(0);
+    }
+
 EX }
 
 EX namespace nisot {
@@ -1370,6 +1453,11 @@ EX namespace nisot {
       set_geometry(gRotSpace);
       return 0;
       }
+    else if(argis("-rot_uscale")) {
+      PHASEFROM(2);
+      shift_arg_formula(rots::underlying_scale);
+      return 0;
+      }
     return 1;
     });