diff --git a/polymer/eduke32/build/include/build.h b/polymer/eduke32/build/include/build.h
index f42239b9d..2eadcc913 100644
--- a/polymer/eduke32/build/include/build.h
+++ b/polymer/eduke32/build/include/build.h
@@ -41,6 +41,7 @@ extern "C" {
 #define MAXYDIM 3200
 #define MAXBASEPALS 8
 #define MAXPALOOKUPS 256
+#define MAXPSKYMULTIS 8
 #define MAXPSKYTILES 256
 #define MAXSPRITESONSCREEN 4096
 #define MAXUNIQHUDID 256 //Extra slots so HUD models can store animation state without messing game sprites
@@ -81,13 +82,16 @@ void yax_updategrays(int32_t posze);
 # define YAX_ITER_WALLS(Wal, Itervar, Cfvar) Cfvar=0, Itervar=(Wal); Itervar!=-1; \
     Itervar=yax_getnextwall(Itervar, Cfvar), (void)(Itervar==-1 && Cfvar==0 && (Cfvar=1) && (Itervar=yax_getnextwall((Wal), Cfvar)))
 
+extern int16_t yax_bunchnum[MAXSECTORS][2];
+extern int16_t yax_nextwall[MAXWALLS][2];
+
 int16_t yax_getbunch(int16_t i, int16_t cf);
 void yax_getbunches(int16_t i, int16_t *cb, int16_t *fb);
 void yax_setbunch(int16_t i, int16_t cf, int16_t bunchnum);
 void yax_setbunches(int16_t i, int16_t cb, int16_t fb);
 int16_t yax_getnextwall(int16_t wal, int16_t cf);
 void yax_setnextwall(int16_t wal, int16_t cf, int16_t thenextwall);
-void yax_update(int32_t onlyreset);
+void yax_update(int32_t resetstat);
 int32_t yax_getneighborsect(int32_t x, int32_t y, int32_t sectnum, int32_t cf, int16_t *ret_bunchnum);
 
 static inline int32_t yax_waltosecmask(int32_t walclipmask)
@@ -297,7 +301,12 @@ EXTERN int32_t visibility, parallaxvisibility;
 EXTERN int32_t windowx1, windowy1, windowx2, windowy2;
 EXTERN int16_t startumost[MAXXDIM], startdmost[MAXXDIM];
 
+// original multi-psky handling (only one per map)
 EXTERN int16_t pskyoff[MAXPSKYTILES], pskybits;
+// new multi-psky -- up to MAXPSKYMULTIS
+EXTERN int16_t pskynummultis;
+EXTERN int16_t pskymultilist[MAXPSKYMULTIS], pskymultibits[MAXPSKYMULTIS];
+EXTERN int16_t pskymultioff[MAXPSKYMULTIS][MAXPSKYTILES];
 
 EXTERN int16_t headspritesect[MAXSECTORS+1], headspritestat[MAXSTATUS+1];
 EXTERN int16_t prevspritesect[MAXSPRITES], prevspritestat[MAXSPRITES];
diff --git a/polymer/eduke32/build/include/editor.h b/polymer/eduke32/build/include/editor.h
index 4629e2bfd..ad40a6252 100644
--- a/polymer/eduke32/build/include/editor.h
+++ b/polymer/eduke32/build/include/editor.h
@@ -45,7 +45,7 @@ extern int32_t zmode, kensplayerheight, zlock;
 //extern int16_t defaultspritecstat;
 
 extern int32_t temppicnum, tempcstat, templotag, temphitag, tempextra;
-extern uint32_t temppal, tempvis, tempxrepeat, tempyrepeat;
+extern uint32_t temppal, tempvis, tempxrepeat, tempyrepeat, tempxpanning, tempypanning;
 extern int32_t tempshade, tempxvel, tempyvel, tempzvel;
 extern char somethingintab;
 
@@ -73,6 +73,10 @@ extern int32_t showambiencesounds;
 extern uint8_t graysectbitmap[MAXSECTORS>>3];
 extern uint8_t graywallbitmap[MAXWALLS>>3];
 
+#ifdef YAX_ENABLE
+int32_t yax_is121(int16_t bunchnum, int16_t getfloor);
+#endif
+
 // editor side view
 extern int32_t m32_sideview;
 extern int32_t m32_sideelev;
diff --git a/polymer/eduke32/build/include/polymost.h b/polymer/eduke32/build/include/polymost.h
index 80c52017f..ddf6a0deb 100644
--- a/polymer/eduke32/build/include/polymost.h
+++ b/polymer/eduke32/build/include/polymost.h
@@ -131,7 +131,11 @@ static inline void fogcalc(const int32_t shade, const int32_t vis, const int32_t
     f = (vis > 239) ? (float)(gvisibility*((vis-240+f)/(klabs(vis-256)))) :
         (float)(gvisibility*(vis+16+f));
 
-    fogresult = clamp(f, 0.001f, 100.f);
+    if (f < 0.001f)
+        f = 0.001f;
+    else if (f > 100.0f)
+        f = 100.0f;
+    fogresult = f;
 
     Bmemcpy(fogcol, &fogtable[pal<<2], sizeof(fogcol));
 }
diff --git a/polymer/eduke32/build/src/build.c b/polymer/eduke32/build/src/build.c
index cfb5f5573..c8ebc00ae 100644
--- a/polymer/eduke32/build/src/build.c
+++ b/polymer/eduke32/build/src/build.c
@@ -109,7 +109,7 @@ int16_t highlightsector[MAXSECTORS], highlightsectorcnt = -1;
 extern char textfont[128][8];
 
 int32_t temppicnum, tempcstat, templotag, temphitag, tempextra;
-uint32_t temppal, tempvis, tempxrepeat, tempyrepeat;
+uint32_t temppal, tempvis, tempxrepeat, tempyrepeat, tempxpanning=0, tempypanning=0;
 int32_t tempshade, tempxvel, tempyvel, tempzvel;
 char somethingintab = 255;
 
@@ -338,6 +338,21 @@ static void M32_drawdebug(void)
 #endif
 
 #ifdef YAX_ENABLE
+// Check whether bunchnum has exactly one corresponding floor and ceiling
+// and return it in this case. If not 1-to-1, return -1.
+int32_t yax_is121(int16_t bunchnum, int16_t getfloor)
+{
+    int32_t i;
+    i = headsectbunch[0][bunchnum];
+    if (i<0 || nextsectbunch[0][i]>=0)
+        return -1;
+    i = headsectbunch[1][bunchnum];
+    if (i<0 || nextsectbunch[1][i]>=0)
+        return -1;
+
+    return headsectbunch[getfloor][bunchnum];
+}
+
 static void yax_fixreverselinks(int16_t oldwall, int16_t newwall)
 {
     int32_t cf, ynw;
@@ -2241,6 +2256,7 @@ void overheadeditor(void)
     int32_t prefixarg = 0;
     int32_t resetsynctics = 0, lasttick=getticks(), waitdelay=totalclock, lastdraw=getticks();
     int32_t tsign;
+    int32_t olen[2]={0,0}, nlen[2]={0,0}, dragwall[2] = {-1, -1};
 
     m32_setkeyfilter(1);
 
@@ -2788,9 +2804,46 @@ void overheadeditor(void)
                 if (linehighlight >= 0)
                 {
                     int32_t secti = sectorofwall(linehighlight);
+#ifdef YAX_ENABLE
+                    int16_t cf, bunchnum, tempsect, tempwall;
+
+                    for (i=0; i<numwalls; i++)
+                        wall[i].cstat &= ~(1<<14);
+
+                    for (cf=0; cf<2; cf++)
+                    {
+                        tempsect = secti;
+                        tempwall = linehighlight;
+
+                        while ((bunchnum = yax_getbunch(tempsect, cf)) >= 0 &&
+                                   (tempsect=yax_is121(bunchnum, cf)) >= 0)
+                        {
+                            tempwall = yax_getnextwall(tempwall, cf);
+                            if (tempwall < 0)
+                                break;  // corrupt!
+                            wall[tempwall].cstat |= (1<<14);
+                        }
+                    }
+
+                    k = 0;
+                    for (i=0; i<numsectors; i++)
+                        for (WALLS_OF_SECTOR(i, j))
+                        {
+                            if (wall[j].cstat & (1<<14))
+                            {
+                                setfirstwall(i, j);
+                                k++;
+                                break;
+                            }
+                        }
+
+                    if (k > 0)
+                        message("Set first walls (sector[].wallptr) for %d sectors", k+1);
+                    else
+#endif
+                    printmessage16("This wall now sector %d's first wall (sector[].wallptr)", secti);
                     setfirstwall(secti, linehighlight);
                     asksave = 1;
-                    printmessage16("This wall now sector %d's first wall (sector[].wallptr)", secti);
                 }
             }
         }
@@ -3049,7 +3102,7 @@ void overheadeditor(void)
 
                     if (highlightsectorcnt>1 && SECTORFLD(highlightsector[i],stat, cf)&2)
                     {
-                        message("Sector %ss must not be sloped", cfs[cf]);
+                        message("Sector %ss must not be sloped if extending more than one", cfs[cf]);
                         goto end_yax;
                     }
                 }
@@ -3565,13 +3618,12 @@ end_yax: ;
                 goto end_after_dragging;
 
             j = 1;
-            if (highlightcnt > 0)
-                for (i=0; i<highlightcnt; i++)
-                    if (pointhighlight == highlight[i])
-                    {
-                        j = 0;
-                        break;
-                    }
+            for (i=0; i<highlightcnt; i++)
+                if (pointhighlight == highlight[i])
+                {
+                    j = 0;
+                    break;
+                }
 
             if (j == 0)
             {
@@ -3588,6 +3640,29 @@ end_yax: ;
             {
                 dax = wall[pointhighlight].x;
                 day = wall[pointhighlight].y;
+
+                for (i=0; i<2; i++)
+                {
+                    if (dragwall[i] < 0)
+                        break;
+
+                    nlen[i] = wallength(dragwall[i]);
+
+                    if (olen[i] != 0 && nlen[i] != 0)
+                    {
+                        int32_t nw = wall[dragwall[i]].nextwall;
+
+                        j = divscale10(nlen[i], olen[i]);
+
+                        k = getlenbyrep(olen[i], wall[dragwall[i]].xrepeat);
+                        fixxrepeat(dragwall[i], k);
+                        if (nw >= 0)
+                        {
+                            k = getlenbyrep(olen[i], wall[nw].xrepeat);
+                            fixxrepeat(nw, k);
+                        }
+                    }
+                }
             }
             else if ((pointhighlight&0xc000) == 16384)
             {
@@ -3595,6 +3670,8 @@ end_yax: ;
                 day = sprite[pointhighlight&16383].y;
             }
 
+            dragwall[0] = dragwall[1] = -1;
+
             for (runi=0; runi<3; runi++)
                 for (i=numwalls-1; i>=0; i--)  //delete points
                 {
@@ -3720,8 +3797,18 @@ end_after_dragging:
             else  //if (highlightsectorcnt <= 0)
             {
                 if ((bstatus&1) > (oldmousebstatus&1))
+                {
                     pointhighlight = getpointhighlight(mousxplc, mousyplc, pointhighlight);
 
+                    if (pointhighlight >= 0)
+                    {
+                        dragwall[0] = lastwall(pointhighlight);
+                        dragwall[1] = pointhighlight;
+                        olen[0] = wallength(dragwall[0]);
+                        olen[1] = wallength(dragwall[1]);
+                    }
+                }
+
                 if (pointhighlight >= 0 && (!m32_sideview || m32_sideelev>=32))
                 {
                     if (m32_sideview)
@@ -4923,7 +5010,8 @@ check_next_sector: ;
                     for (j=numwalls; j<danumwalls; j++)
                     {
 #ifdef YAX_ENABLE
-                        yax_fixreverselinks(j, j);
+//                        if (doSectorSplit || (j!=numwalls && j!=danumwalls-1))
+                            yax_fixreverselinks(j, j);
 #endif
                         if (wall[j].nextwall >= 0)
                         {
@@ -8194,7 +8282,6 @@ static void AlignWalls(int32_t w0, int32_t z0, int32_t w1, int32_t z1, int32_t t
     int32_t n;
 
     //do the x alignment
-    wall[w1].cstat &= ~0x0108;    //Set to non-flip
     wall[w1].xpanning = (uint8_t)((wall[w0].xpanning + (wall[w0].xrepeat<<3))%tilesizx[tilenum]);
 
     for (n=picsiz[tilenum]>>4; (1<<n)<tilesizy[tilenum]; n++);
@@ -8209,6 +8296,8 @@ void AlignWallPoint2(int32_t w0)
     AlignWalls(w0,GetWallBaseZ(w0), w1,GetWallBaseZ(w1), wall[w0].picnum);
 }
 
+#define ALIGN_WALLS_CSTAT_MASK (4+8+256)
+
 // flags:
 //  1: recurse nextwalls
 //  2: iterate point2's
@@ -8216,7 +8305,7 @@ void AlignWallPoint2(int32_t w0)
 int32_t AutoAlignWalls(int32_t w0, uint32_t flags, int32_t nrecurs)
 {
     int32_t z0, z1, tilenum, w1, visible, nextsec, sectnum;
-    static int32_t numaligned, wall0;
+    static int32_t numaligned, wall0, cstat0;
     static uint32_t lenrepquot;
 
     tilenum = wall[w0].picnum;
@@ -8229,6 +8318,7 @@ int32_t AutoAlignWalls(int32_t w0, uint32_t flags, int32_t nrecurs)
         numaligned = 0;
         lenrepquot = getlenbyrep(wallength(w0), wall[w0].xrepeat);
         wall0 = w0;
+        cstat0 = wall[w0].cstat & ALIGN_WALLS_CSTAT_MASK;  // top/bottom orientation; x/y-flip
     }
 
     z0 = GetWallBaseZ(w0);
@@ -8274,6 +8364,8 @@ int32_t AutoAlignWalls(int32_t w0, uint32_t flags, int32_t nrecurs)
                 if ((flags&4) && w0!=wall0)
                     fixxrepeat(w0, lenrepquot);
                 AlignWalls(w0,z0, w1,z1, tilenum);
+                wall[w1].cstat &= ~ALIGN_WALLS_CSTAT_MASK;
+                wall[w1].cstat |= cstat0;
                 numaligned++;
 
                 //if wall was 1-sided, no need to recurse
diff --git a/polymer/eduke32/build/src/defs.c b/polymer/eduke32/build/src/defs.c
index daed7423f..570708258 100644
--- a/polymer/eduke32/build/src/defs.c
+++ b/polymer/eduke32/build/src/defs.c
@@ -548,7 +548,7 @@ static int32_t defsparser(scriptfile *script)
                 //            initprintf("got bpl %d xsiz %d ysiz %d\n",bpl,xsiz,ysiz);
 
                 ftd = Bmalloc(xsiz*ysiz);
-                faketiledata[tile] = Bmalloc(xsiz*ysiz);
+                faketiledata[tile] = Bmalloc(xsiz*ysiz + 400);
 
                 for (i=xsiz-1; i>=0; i--)
                 {
@@ -600,7 +600,7 @@ static int32_t defsparser(scriptfile *script)
 //            initprintf("got bpl %d xsiz %d ysiz %d\n",bpl,xsiz,ysiz);
 
             ftd = Bmalloc(xsiz*ysiz);
-            faketiledata[tile] = Bmalloc(xsiz*ysiz);
+            faketiledata[tile] = Bmalloc(xsiz*ysiz + 400);
 
             for (i=xsiz-1; i>=0; i--)
             {
diff --git a/polymer/eduke32/build/src/engine.c b/polymer/eduke32/build/src/engine.c
index ed3671af1..21a660415 100644
--- a/polymer/eduke32/build/src/engine.c
+++ b/polymer/eduke32/build/src/engine.c
@@ -188,10 +188,10 @@ int16_t editstatus = 0;
 
 ////////// YAX //////////
 
-#if YAX_M32_DEBUG
+#ifdef YAX_DEBUG
 extern char m32_debugstr[64][128];
 extern int32_t m32_numdebuglines;
-# define yaxdebug(fmt, ...)  do { if (m32_numdebuglines<64) Bsprintf(m32_debugstr[m32_numdebuglines++], fmt, ##__VA_ARGS__); } while (0)
+# define yaxdebug(fmt, ...)  do { if (m32_numdebuglines<64) Bsnprintf(m32_debugstr[m32_numdebuglines++], 128, fmt, ##__VA_ARGS__); } while (0)
 #else
 # define yaxdebug(fmt, ...)
 #endif
@@ -242,6 +242,7 @@ static int32_t scansector_retfast = 0;
 static int32_t scansector_collectsprites = 1;
 static int32_t yax_globalcf = -1;
 static int32_t yax_globallev = YAX_MAXDRAWS;
+//static int32_t yax_globalbunch = -1;
 
 // duplicated tsprites
 //  [i]:
@@ -252,8 +253,8 @@ static int16_t yax_spritesortcnt[1 + 2*YAX_MAXDRAWS];
 static int16_t yax_tsprite[1 + 2*YAX_MAXDRAWS][MAXSPRITESONSCREEN];
 
 // game-time YAX data structures
-static int16_t yax_bunchnum[MAXSECTORS][2];
-static int16_t yax_nextwall[MAXWALLS][2];
+int16_t yax_bunchnum[MAXSECTORS][2];
+int16_t yax_nextwall[MAXWALLS][2];
 
 static int32_t yax_islockededge(/*int16_t sec,*/ int16_t line, int16_t cf)
 #if 1
@@ -364,7 +365,10 @@ void yax_setnextwall(int16_t wal, int16_t cf, int16_t thenextwall)
 }
 
 //// in-struct --> array transfer; list construction
-void yax_update(int32_t onlyreset)
+// resetstat:  0: reset and read data from structs and construct linked lists etc.
+//             1: only reset
+//             2: read data from game-time arrays and construct linked lists etc.
+void yax_update(int32_t resetstat)
 {
 // TODO: always make bunchnums consecutive
     int32_t i, j, oeditstatus=editstatus;
@@ -374,39 +378,46 @@ void yax_update(int32_t onlyreset)
 
     for (i=0; i<MAXSECTORS; i++)
     {
-        yax_bunchnum[i][0] = yax_bunchnum[i][1] = -1;
+        if (resetstat != 2 || i>=numsectors)
+            yax_bunchnum[i][0] = yax_bunchnum[i][1] = -1;
         nextsectbunch[0][i] = nextsectbunch[1][i] = -1;
     }
     for (i=0; i<YAX_MAXBUNCHES; i++)
         headsectbunch[0][i] = headsectbunch[1][i] = -1;
     for (i=0; i<MAXWALLS; i++)
-        yax_nextwall[i][0] = yax_nextwall[i][1] = -1;
+        if (resetstat != 2 || i>=numwalls)
+            yax_nextwall[i][0] = yax_nextwall[i][1] = -1;
 
-    if (onlyreset)
+    if (resetstat==1)
         return;
 
     // constuct singly linked list of sectors-of-bunch
-    editstatus = 1;  // read bunchnums directly from the sector struct!
+    editstatus = (resetstat==0);  // read bunchnums directly from the sector struct!
     for (i=numsectors-1; i>=0; i--)
     {
         yax_getbunches(i, &cb, &fb);
-        yax_bunchnum[i][0] = cb;
-        yax_bunchnum[i][1] = fb;
+        if (resetstat==0)
+        {
+            yax_bunchnum[i][0] = cb;
+            yax_bunchnum[i][1] = fb;
+        }
 
         if (cb >= 0)
         {
-            for (j=sector[i].wallptr; j<sector[i].wallptr+sector[i].wallnum; j++)
-            {
-                if (yax_islockededge(j,YAX_CEILING))
-                    yax_nextwall[j][0] = YAX_NEXTWALL(j,0);
-            }
+            if (resetstat==0)
+                for (j=sector[i].wallptr; j<sector[i].wallptr+sector[i].wallnum; j++)
+                {
+                    if (yax_islockededge(j,YAX_CEILING))
+                        yax_nextwall[j][0] = YAX_NEXTWALL(j,0);
+                }
 
             if (headsectbunch[0][cb] == -1)
             {
                 headsectbunch[0][cb] = i;
                 // not duplicated in floors, since every extended ceiling
                 // must have a corresponding floor:
-                numyaxbunches++;
+                if (resetstat==0)
+                    numyaxbunches++;
             }
             else
             {
@@ -418,11 +429,12 @@ void yax_update(int32_t onlyreset)
 
         if (fb >= 0)
         {
-            for (j=sector[i].wallptr; j<sector[i].wallptr+sector[i].wallnum; j++)
-            {
-                if (yax_islockededge(j,YAX_FLOOR))
-                    yax_nextwall[j][1] = YAX_NEXTWALL(j,1);
-            }
+            if (resetstat==0)
+                for (j=sector[i].wallptr; j<sector[i].wallptr+sector[i].wallnum; j++)
+                {
+                    if (yax_islockededge(j,YAX_FLOOR))
+                        yax_nextwall[j][1] = YAX_NEXTWALL(j,1);
+                }
 
             if (headsectbunch[1][fb] == -1)
                 headsectbunch[1][fb] = i;
@@ -456,31 +468,35 @@ int32_t yax_getneighborsect(int32_t x, int32_t y, int32_t sectnum, int32_t cf, i
     return -1;
 }
 
-// >0 b2 is farther away than b1
+static inline int32_t yax_walldist(int32_t w)
+{
+    return klabs(wall[w].x-globalposx) + klabs(wall[w].y-globalposy);
+}
+
 static int yax_cmpbunches(const int16_t *b1, const int16_t *b2)
 {
     int32_t s1,s2, w1,w2;
-#if 1
-    int32_t dx1,dy1, dx2,dy2, r;
-#else
-    int64_t dx1,dy1, dx2,dy2, r;
-#endif
+
     s1 = headsectbunch[yax_globalcf][*b1];
     s2 = headsectbunch[yax_globalcf][*b2];
 
     w1 = sector[s1].wallptr;
     w2 = sector[s2].wallptr;
 
-    dx1 = wall[w1].x-globalposx; dy1 = wall[w1].y-globalposy;
-    dx2 = wall[w2].x-globalposx; dy2 = wall[w2].y-globalposy;
 #if 1
-    r = klabs(dx2+dy2) - klabs(dx1+dy1);
-    return r;
+    return (yax_walldist(w2) - yax_walldist(w1));
 #else
-    r = (dx2*dx2 + dy2*dy2) - (dx1*dx1 + dy1*dy1);
-    if (r > 0)
-        return 1;
-    return r>>63;
+    {
+        int64_t dx1,dy1, dx2,dy2, r;
+
+        dx1 = wall[w1].x-globalposx; dy1 = wall[w1].y-globalposy;
+        dx2 = wall[w2].x-globalposx; dy2 = wall[w2].y-globalposy;
+
+        r = (dx2*dx2 + dy2*dy2) - (dx1*dx1 + dy1*dy1);
+        if (r > 0)
+            return 1;
+        return r>>63;
+    }
 #endif
 }
 
@@ -491,27 +507,55 @@ static int32_t yax_getbestsector(int32_t bunchnum, int32_t cf, const int16_t *ou
     if (bunchnum==ourbunch[cf])
     {
         k = yax_getneighborsect(globalposx, globalposy, sectnum, cf, NULL);
-        if (k < 0)
-            k = headsectbunch[!cf][bunchnum];
-        return k;
+        if (k >= 0)
+            return k;
     }
-    else
+
     {
-//        return headsectbunch[!cf][bunchnum];
+        int32_t j, walldist, bestsec=-1, bestwalldist=INT32_MAX;
+        int32_t startwall, endwall, checkthis;
 
         scansector_retfast = 1;
         scansector_collectsprites = 0;
         for (k = headsectbunch[!cf][bunchnum]; k != -1; k = nextsectbunch[!cf][k])
         {
-            numscans = numbunches = 0;
-            scansector(k);
-            if (numbunches > 0)
-                break;
+            startwall = sector[k].wallptr;
+            endwall = startwall+sector[k].wallnum;
+
+            checkthis = 0;
+            for (j=startwall; j<endwall; j++)
+            {
+/*
+                if (wall[j].nextsector == globalcursectnum)
+                {
+                    scansector_collectsprites = 1;
+                    scansector_retfast = 0;
+                    return k;
+                }
+*/
+                walldist = yax_walldist(j);
+                if (walldist < bestwalldist)
+                {
+                    checkthis = 1;
+                    bestwalldist = walldist;
+                }
+            }
+
+            if (checkthis)
+            {
+                numscans = numbunches = 0;
+                scansector(k);
+                if (numbunches > 0)
+                    bestsec = k;
+            }
         }
         scansector_collectsprites = 1;
         scansector_retfast = 0;
 
-        return k;
+        if (bestsec < 0)
+            bestsec = headsectbunch[!cf][bunchnum];
+
+        return bestsec;
     }
 }
 
@@ -538,14 +582,15 @@ static void yax_tweakpicnums(int32_t bunchnum, int32_t cf, int32_t restore)
         }
 }
 
-static void yax_copytsprite(int16_t curbunchnum)
+static void yax_copytsprite(int32_t curbunchnum, int32_t resetsortcnt)
 {
     int16_t bunchnum;
     int32_t i, spritenum, gotthrough, sectnum, cf;
     int32_t sortcnt = yax_spritesortcnt[yax_globallev];
     const spritetype *spr;
 
-    spritesortcnt = 0;
+    if (resetsortcnt)
+        spritesortcnt = 0;
 
     for (i=0; i<sortcnt; i++)
     {
@@ -574,6 +619,9 @@ static void yax_copytsprite(int16_t curbunchnum)
                 continue;
         }
 
+        if (spritesortcnt >= MAXSPRITESONSCREEN)
+            break;
+
         Bmemcpy(&tsprite[spritesortcnt], spr, sizeof(spritetype));
         spriteext[spritenum].tspr = &tsprite[spritesortcnt];
         tsprite[spritesortcnt].owner = spritenum;
@@ -605,7 +653,9 @@ void yax_drawrooms(void (*ExtAnalyzeSprites)(void), int32_t horiz, int16_t sectn
 
     // original (1st-draw) and accumulated ('per-level') gotsector bitmaps
     static uint8_t ogotsector[MAXSECTORS>>3], lgotsector[MAXSECTORS>>3];
-//    int32_t t;
+#ifdef YAX_DEBUG
+    int32_t t;
+#endif
 
     if (rendmode!=0 || numyaxbunches==0)
     {
@@ -649,10 +699,15 @@ void yax_drawrooms(void (*ExtAnalyzeSprites)(void), int32_t horiz, int16_t sectn
                 j = yax_getbunch(i, cf);
                 if (j >= 0 && !(havebunch[j>>3]&(1<<(j&7))))
                 {
-                    havebunch[j>>3] |= (1<<(j&7));
-                    bunches[cf][bnchnum[cf]++] = j;
-                    bnchend[lev][cf]++;
-                    numhere++;
+                    if ((SECTORFLD(i,stat, cf)&2) ||
+                            (cf==0 && globalposz > sector[i].ceilingz) ||
+                            (cf==1 && globalposz < sector[i].floorz))
+                    {
+                        havebunch[j>>3] |= (1<<(j&7));
+                        bunches[cf][bnchnum[cf]++] = j;
+                        bnchend[lev][cf]++;
+                        numhere++;
+                    }
                 }
             }
 
@@ -668,22 +723,20 @@ void yax_drawrooms(void (*ExtAnalyzeSprites)(void), int32_t horiz, int16_t sectn
                 for (bnchcnt=bbeg; bnchcnt < bbeg+numhere; bnchcnt++)
                 {
                     j = bunches[cf][bnchcnt];  // the actual bunchnum...
-
-//                    t=getticks();
+//                    yax_globalbunch = j;
+#ifdef YAX_DEBUG
+                    t=getticks();
+#endif
                     k = yax_getbestsector(j, cf, ourbunch, sectnum);
                     bestsec[cf][bnchcnt] = k;
                     if (k < 0)
                     {
-//                        initprintf("cf %d, lev %d: skipped bunch %d\n", cf, lev, j);
+#ifdef YAX_DEBUG
+                        initprintf("%s, l %d: skipped bunch %d\n", cf?"v":"^", lev, j);
+#endif
                         continue;
                     }
 
-                    if (ourbunch[cf]==j)
-                    {
-                        ourbunch[cf] = yax_getbunch(k, cf);
-                        sectnum = k;
-                    }
-
                     if (lev != YAX_MAXDRAWS-1)
                     {
                         // +MAXSECTORS: force
@@ -692,8 +745,15 @@ void yax_drawrooms(void (*ExtAnalyzeSprites)(void), int32_t horiz, int16_t sectn
                             for (i=0; i<(numsectors+7)>>3; i++)
                                 lgotsector[i] |= gotsector[i];
 
-//                        yaxdebug("cf %d, lev %d: fake-drawn sec %d (bunch %d), %d dspr, %2d ms",
-//                                 cf, lev, k, j, yax_spritesortcnt[yax_globallev], getticks()-t);
+                        yaxdebug("%s, l %d: faked sec %3d (bunch %2d),%3d dspr, ob=[%2d,%2d], sn=%3d,%3d ms",
+                                 cf?"v":"^", lev, k, j, yax_spritesortcnt[yax_globallev],
+                                 ourbunch[0],ourbunch[1],sectnum,getticks()-t);
+                    }
+
+                    if (ourbunch[cf]==j)
+                    {
+                        ourbunch[cf] = yax_getbunch(k, cf);
+                        sectnum = k;
                     }
                 }
 
@@ -716,7 +776,7 @@ void yax_drawrooms(void (*ExtAnalyzeSprites)(void), int32_t horiz, int16_t sectn
     g_nodraw = 0;
     scansector_collectsprites = 0;
 
-#if 0
+#ifdef ENGINE_CLEAR_SCREEN
     begindrawing();
     for (i=0; i<xdim*ydim; i++)
         *((char *)frameplace + i) = i;
@@ -728,23 +788,26 @@ void yax_drawrooms(void (*ExtAnalyzeSprites)(void), int32_t horiz, int16_t sectn
         for (lev=maxlev[cf]; lev>=0; lev--)
         {
             yax_globallev = YAX_MAXDRAWS + (-1 + 2*cf)*(lev+1);
+            scansector_collectsprites = (lev == YAX_MAXDRAWS-1);
 
             for (bnchcnt=bnchbeg[lev][cf]; bnchcnt<bnchend[lev][cf]; bnchcnt++)
             {
                 j = bunches[cf][bnchcnt];  // the actual bunchnum...
                 k = bestsec[cf][bnchcnt];  // best start-drawing sector
-
-//                t=getticks();
+//                yax_globalbunch = j;
+#ifdef YAX_DEBUG
+                t=getticks();
+#endif
                 yax_tweakpicnums(j, cf, 0);
                 if (k < 0)
                     continue;
 
                 drawrooms(globalposx,globalposy,globalposz,globalang,horiz,k+MAXSECTORS);  // +MAXSECTORS: force
 
-                yax_copytsprite(j);
+                yax_copytsprite(j, !scansector_collectsprites);
 
-//                yaxdebug("cf %d, lev %d: DRAWN sec %d (bunch %d), %d tspr, %2d ms",
-//                         cf, lev, k, j, spritesortcnt, getticks()-t);
+                yaxdebug("%s, l %d: DRAWN sec %3d (bunch %2d),%3d tspr,%3d ms",
+                         cf?"v":"^", lev, k, j, spritesortcnt, getticks()-t);
 
                 ExtAnalyzeSprites();
                 drawmasks();
@@ -756,22 +819,23 @@ void yax_drawrooms(void (*ExtAnalyzeSprites)(void), int32_t horiz, int16_t sectn
         }
     }
 
-//    t=getticks();
-
+#ifdef YAX_DEBUG
+    t=getticks();
+#endif
     yax_globallev = YAX_MAXDRAWS;
+    scansector_collectsprites = 0;
 
     // draw base level
     drawrooms(globalposx,globalposy,globalposz,globalang,horiz,osectnum);
+    yaxdebug("DRAWN base level sec %d, %2d ms", osectnum, getticks()-t);
 
-    yax_copytsprite(-1);
-
+    yax_copytsprite(-1, scansector_collectsprites);
     scansector_collectsprites = 1;
 
     for (cf=0; cf<2; cf++)
         if (maxlev[cf] >= 0)
             for (bnchcnt=bnchbeg[0][cf]; bnchcnt<bnchend[0][cf]; bnchcnt++)
                 yax_tweakpicnums(bunches[cf][bnchcnt], cf, 1);  // restore picnums
-//    yaxdebug("DRAWN base level sec %d, %2d ms", osectnum, getticks()-t);
 
 #ifdef ENGINE_SCREENSHOT_DEBUG
     engine_screenshot = 0;
@@ -3710,6 +3774,10 @@ static void parascan(int32_t dax1, int32_t dax2, int32_t sectnum, char dastat, i
     int32_t j, k, l, m, n, x, z, wallnum, nextsectnum, globalhorizbak;
     int16_t *topptr, *botptr;
 
+    int16_t dapskybits;
+    static const int16_t zeropskyoff[MAXPSKYTILES];
+    const int16_t *dapskyoff;
+
     UNREFERENCED_PARAMETER(dax1);
     UNREFERENCED_PARAMETER(dax2);
 
@@ -3752,7 +3820,20 @@ static void parascan(int32_t dax1, int32_t dax2, int32_t sectnum, char dastat, i
     globalyscale = (8<<(globalshiftval-19));
     //if (globalorientation&256) globalyscale = -globalyscale, globalzd = -globalzd;
 
-    k = 11 - (picsiz[globalpicnum]&15) - pskybits;
+    dapskyoff = zeropskyoff;
+    dapskybits = pskybits;
+
+    for (j=0; j<pskynummultis; j++)
+    {
+        if (globalpicnum == pskymultilist[j])
+        {
+            dapskybits = pskymultibits[j];
+            dapskyoff = pskymultioff[j];
+            break;
+        }
+    }
+
+    k = 11 - (picsiz[globalpicnum]&15) - dapskybits;
     x = -1;
 
     for (z=bunchfirst[bunch]; z>=0; z=p2[z])
@@ -3792,7 +3873,7 @@ static void parascan(int32_t dax1, int32_t dax2, int32_t sectnum, char dastat, i
         else if (x >= 0)
         {
             l = globalpicnum; m = (picsiz[globalpicnum]&15);
-            globalpicnum = l+pskyoff[lplc[x]>>m];
+            globalpicnum = l + dapskyoff[lplc[x]>>m];
 
             if (((lplc[x]^lplc[xb1[z]-1])>>m) == 0)
                 wallscan(x,xb1[z]-1,topptr,botptr,swplc,lplc);
@@ -3801,7 +3882,7 @@ static void parascan(int32_t dax1, int32_t dax2, int32_t sectnum, char dastat, i
                 j = x;
                 while (x < xb1[z])
                 {
-                    n = l+pskyoff[lplc[x]>>m];
+                    n = l + dapskyoff[lplc[x]>>m];
                     if (n != globalpicnum)
                     {
                         wallscan(j,x-1,topptr,botptr,swplc,lplc);
@@ -3822,7 +3903,7 @@ static void parascan(int32_t dax1, int32_t dax2, int32_t sectnum, char dastat, i
     if (x >= 0)
     {
         l = globalpicnum; m = (picsiz[globalpicnum]&15);
-        globalpicnum = l+pskyoff[lplc[x]>>m];
+        globalpicnum = l + dapskyoff[lplc[x]>>m];
 
         if (((lplc[x]^lplc[xb2[bunchlast[bunch]]])>>m) == 0)
             wallscan(x,xb2[bunchlast[bunch]],topptr,botptr,swplc,lplc);
@@ -3831,7 +3912,7 @@ static void parascan(int32_t dax1, int32_t dax2, int32_t sectnum, char dastat, i
             j = x;
             while (x <= xb2[bunchlast[bunch]])
             {
-                n = l+pskyoff[lplc[x]>>m];
+                n = l + dapskyoff[lplc[x]>>m];
                 if (n != globalpicnum)
                 {
                     wallscan(j,x-1,topptr,botptr,swplc,lplc);
@@ -4039,7 +4120,12 @@ static void drawalls(int32_t bunch)
             {
                 if ((fz[2] >= fz[0]) && (fz[3] >= fz[1]))
                 {
-                    if (globparaflorclip)
+                    if (globparaflorclip
+#ifdef YAX_ENABLE
+//                        || ((sec->floorstat&2) && yax_globallev < YAX_MAXDRAWS)
+//                            || yax_getbunch(wallnum, YAX_FLOOR) < 0
+#endif
+                        )
                         for (x=x1; x<=x2; x++)
                             if (dplc[x] < dmost[x])
                                 if (umost[x] <= dmost[x])
@@ -4236,13 +4322,41 @@ static void drawalls(int32_t bunch)
         }
 
 #ifdef ENGINE_SCREENSHOT_DEBUG
-        if (engine_screenshot && !g_nodraw)
+        if (engine_screenshot)
+#ifdef YAX_ENABLE
+        if (!g_nodraw)
+#endif
         {
             static char fn[BMAX_PATH];
+            static char bakframe[MAXXDIM*MAXYDIM];
+
+            char purple = getclosestcol(63, 0, 63);
+            char yellow = getclosestcol(63, 63, 0);
+
+            begindrawing();  //{{{
+            Bmemcpy(bakframe, (char *)frameplace, xdim*ydim);
+            for (x=0; x<xdim; x++)
+            {
+                if (umost[x] > dmost[x])
+                {
+                    *((char *)frameplace + (ydim/2)*bytesperline + x) = yellow;
+                    *((char *)frameplace + (ydim/2+1)*bytesperline + x) = purple;
+                    continue;
+                }
+
+                if (umost[x] >= 0 || umost[x] < ydim)
+                    *((char *)frameplace + umost[x]*bytesperline + x) = purple;
+
+                if (dmost[x]-1 >= 0 || dmost[x]-1 < ydim)
+                    *((char *)frameplace + (dmost[x]-1)*bytesperline + x) = yellow;
+            }
 
             Bsprintf(fn, "engshot%04d.png", engine_screenshot);
             screencapture(fn, 0, "BUILD engine");
             engine_screenshot++;
+
+            Bmemcpy((char *)frameplace, bakframe, xdim*ydim);
+            enddrawing();  //}}}
         }
 #endif
     }
@@ -7102,6 +7216,7 @@ int32_t initengine(void)
     xyaspect = -1;
 
     pskyoff[0] = 0; pskybits = 0;
+    pskynummultis = 0;
 
     parallaxtype = 2; parallaxyoffs = 0L; parallaxyscale = 65536;
     showinvisibility = 0;
@@ -7261,7 +7376,7 @@ void drawrooms(int32_t daposx, int32_t daposy, int32_t daposz,
 
     i = mulscale16(xdimenscale,viewingrangerecip);
     globalpisibility = mulscale16(parallaxvisibility,i);
-    globalvisibility = mulscale16(visibility,i);
+    globalvisibility = rendmode==0 ? mulscale16(visibility,i) : scale(visibility<<2,4,3);
     globalhisibility = mulscale16(globalvisibility,xyaspect);
     globalcisibility = mulscale8(globalhisibility,320);
 
@@ -7313,6 +7428,15 @@ void drawrooms(int32_t daposx, int32_t daposy, int32_t daposz,
 
     begindrawing(); //{{{
 
+#ifdef ENGINE_CLEAR_SCREEN
+#ifdef YAX_ENABLE
+    if (!g_nodraw)
+#endif
+    if (numyaxbunches==0)
+        for (i=0; i<xdim*ydim; i++)
+            *((char *)frameplace + i) = i;
+#endif
+
     //frameoffset = frameplace + viewoffset;
     frameoffset = frameplace + windowy1*bytesperline + windowx1;
 
@@ -10103,7 +10227,7 @@ int32_t hitscan(const vec3_t *sv, int16_t sectnum, int32_t vx, int32_t vy, int32
     intptr_t tmp[3], *tmpptr=NULL;
 #ifdef YAX_ENABLE
     vec3_t newsv;
-    int32_t oldhitsect = -1;
+    int32_t oldhitsect = -1, oldhitsect2 = -2;
 #endif
     hitinfo->hitsect = -1; hitinfo->hitwall = -1; hitinfo->hitsprite = -1;
     if (sectnum < 0) return(-1);
@@ -10385,7 +10509,8 @@ restart_grand:
     if (numyaxbunches == 0 || editstatus)
         return 0;
 
-    if (hitinfo->hitsprite==-1 && hitinfo->hitwall==-1 && hitinfo->hitsect!=oldhitsect)
+    if (hitinfo->hitsprite==-1 && hitinfo->hitwall==-1 && hitinfo->hitsect!=oldhitsect
+        && hitinfo->hitsect != oldhitsect2)  // 'ping-pong' infloop protection
     {
         if (hitinfo->hitsect == -1 && oldhitsect >= 0)
         {
@@ -10409,6 +10534,7 @@ restart_grand:
             sectnum = i;
             sv = &newsv;
 
+            oldhitsect2 = oldhitsect;
             oldhitsect = hitinfo->hitsect;
             hitinfo->hitsect = -1;
 
@@ -11679,6 +11805,10 @@ void getzrange(const vec3_t *pos, int16_t sectnum,
     dawalclipmask = (cliptype&65535);
     dasprclipmask = (cliptype>>16);
 
+#ifdef YAX_ENABLE
+    origclipsectorlist[0] = sectnum;
+    origclipsectnum = 1;
+#endif
     clipsectorlist[0] = sectnum;
     clipsectcnt = 0; clipsectnum = 1;
     clipspritecnt = clipspritenum = 0;
@@ -11792,7 +11922,10 @@ restart_grand:
                 if (dx > 0) dax += dx*MAXCLIPDIST; else dax -= dx*MAXCLIPDIST;
                 if (dy > 0) day -= dy*MAXCLIPDIST; else day += dy*MAXCLIPDIST;
                 if (dax >= day) continue;
-
+#ifdef YAX_ENABLE
+                if (mcf==-1 && curspr==NULL)
+                    origclipsectorlist[origclipsectnum++] = k;
+#endif
                 //It actually got here, through all the continue's!!!
                 getzsofslope(k, pos->x,pos->y, &daz,&daz2);
                 if (curspr)
@@ -11963,12 +12096,6 @@ restart_grand:
         int16_t cb, fb, didchange;
         yax_getbunches(sectnum, &cb, &fb);
 
-        if (mcf==-1)
-        {
-            Bmemcpy(origclipsectorlist, clipsectorlist, clipsectnum*sizeof(clipsectorlist[0]));
-            origclipsectnum = clipsectnum;
-        }
-
         mcf++;
         clipsectcnt = 0; clipsectnum = 0;
 
diff --git a/polymer/eduke32/build/src/engine_priv.h b/polymer/eduke32/build/src/engine_priv.h
index 468984292..4143f3a66 100644
--- a/polymer/eduke32/build/src/engine_priv.h
+++ b/polymer/eduke32/build/src/engine_priv.h
@@ -8,8 +8,12 @@
 #define MAXNODESPERLINE 42   //Warning: This depends on MAXYSAVES & MAXYDIM!
 #define MAXCLIPDIST 1024
 
+// uncomment to clear the screen before each top-level draw
+// (classic only)
+// #define ENGINE_CLEAR_SCREEN
+
 #ifdef YAX_ENABLE
-# define YAX_MAXDRAWS 4
+# define YAX_MAXDRAWS 8
 #endif
 
 extern uint8_t **basepaltableptr;
diff --git a/polymer/eduke32/build/src/polymost.c b/polymer/eduke32/build/src/polymost.c
index 672014f53..ee0404a3d 100644
--- a/polymer/eduke32/build/src/polymost.c
+++ b/polymer/eduke32/build/src/polymost.c
@@ -1486,7 +1486,7 @@ void writexcache(char *fn, int32_t len, int32_t dameth, char effect, texcachehea
             if (!picc) goto failure; else pic = picc;
             alloclen = miplen;
 
-            picc = Brealloc(packbuf, alloclen+16);
+            picc = Brealloc(packbuf, alloclen+400);
             if (!picc) goto failure; else packbuf = picc;
 
             picc = Brealloc(midbuf, miplen);
diff --git a/polymer/eduke32/source/actors.c b/polymer/eduke32/source/actors.c
index 9326a994c..0ac702c6a 100644
--- a/polymer/eduke32/source/actors.c
+++ b/polymer/eduke32/source/actors.c
@@ -412,9 +412,13 @@ int32_t A_MoveSprite(int32_t spritenum, const vec3_t *change, uint32_t cliptype)
     {
         spr->z = daz;
 #ifdef YAX_ENABLE
-        if (change->z && yax_getbunch(spr->sectnum, !!change->z)>=0)
-            if ((SECTORFLD(spr->sectnum,stat, !!change->z)&yax_waltosecmask(cliptype))==0)
+        if (change->z && yax_getbunch(spr->sectnum, (change->z>0))>=0)
+            if ((SECTORFLD(spr->sectnum,stat, (change->z>0))&yax_waltosecmask(cliptype))==0)
+            {
+//                initprintf("spr %d, sect %d: chz=%d, cfz=[%d,%d]\n", spritenum, spr->sectnum, change->z,
+//                           actor[spritenum].ceilingz, actor[spritenum].floorz);
                 setspritez(spritenum, (vec3_t *)spr);
+            }
 #endif
     }
     else if (retval == 0) retval = 16384+dasectnum;
@@ -3279,7 +3283,6 @@ ACTOR_STATIC void G_MoveTransports(void)
                         vect.x = g_player[p].ps->pos.x;
                         vect.y = g_player[p].ps->pos.y;
                         vect.z = g_player[p].ps->pos.z+PHEIGHT;
-
                         setsprite(g_player[p].ps->i,&vect);
 
                         P_UpdateScreenPal(g_player[p].ps);
@@ -5625,7 +5628,10 @@ ACTOR_STATIC void G_MoveEffectors(void)   //STATNUM 3
 
             if (s->owner == -1)
             {
-                Bsprintf(tempbuf,"Could not find any locators for SE# 6 and 14 with a hitag of %" PRIdPTR ".\n",t[3]);
+                // debugging subway cars (mapping-wise) is freakin annoying
+                // let's at least have a helpful message...
+                Bsprintf(tempbuf,"Could not find any locators in sector %d"
+                         " for SE# 6 or 14 with hitag %d.\n", (int)t[0], (int)t[3]);
                 G_GameExit(tempbuf);
             }
 
diff --git a/polymer/eduke32/source/astub.c b/polymer/eduke32/source/astub.c
index c67e317df..61e86dff5 100644
--- a/polymer/eduke32/source/astub.c
+++ b/polymer/eduke32/source/astub.c
@@ -191,21 +191,6 @@ static uint8_t wallflag[MAXWALLS>>3];
 static uint8_t havebunch[YAX_MAXBUNCHES];
 static int32_t *tempzar[YAX_MAXBUNCHES];
 
-// Check whether bunchnum has exactly one corresponding floor and ceiling
-// and return it in this case. If not 1-to-1, return -1.
-static int32_t yax_is121(int16_t bunchnum, int16_t getfloor)
-{
-    int32_t i;
-    i = headsectbunch[0][bunchnum];
-    if (i<0 || nextsectbunch[0][i]>=0)
-        return -1;
-    i = headsectbunch[1][bunchnum];
-    if (i<0 || nextsectbunch[1][i]>=0)
-        return -1;
-
-    return headsectbunch[getfloor][bunchnum];
-}
-
 static void silentmessage(const char *fmt, ...);
 static int32_t yax_invalidop()
 {
@@ -693,15 +678,60 @@ const char *ExtGetVer(void)
     return s_buildRev;
 }
 
+static void MultiPskyInit(void)
+{
+    int32_t i;
+
+    // new-style multi-psky handling
+    pskymultilist[0] = MOONSKY1;
+    pskymultilist[1] = BIGORBIT1;
+    pskymultilist[2] = LA;
+    for (i=0; i<3; i++)
+    {
+        pskymultibits[i] = 3;
+        Bmemset(pskymultioff[i], 0, sizeof(pskymultioff[i]));
+    }
+
+    // MOONSKY1
+    //        earth          mountian   mountain         sun
+    pskymultioff[0][6]=1;
+    pskymultioff[0][1]=2;
+    pskymultioff[0][4]=2;
+    pskymultioff[0][2]=3;
+
+    // BIGORBIT1   // orbit
+    //       earth1         2           3           moon/sun
+    pskymultioff[1][5]=1;
+    pskymultioff[1][6]=2;
+    pskymultioff[1][7]=3;
+    pskymultioff[1][2]=4;
+
+    // LA // la city
+    //       earth1         2           3           moon/sun
+    pskymultioff[2][0]=1;
+    pskymultioff[2][1]=2;
+    pskymultioff[2][2]=1;
+    pskymultioff[2][3]=3;
+    pskymultioff[2][4]=4;
+    pskymultioff[2][5]=0;
+    pskymultioff[2][6]=2;
+    pskymultioff[2][7]=3;
+
+    pskynummultis = 3;
+}
+
 void ExtLoadMap(const char *mapname)
 {
     int32_t i;
-    int32_t sky=0;
+    int32_t sky=-1;
 
     getmessageleng = 0;
     getmessagetimeoff = 0;
 
     Bstrcpy(levelname,mapname);
+
+    // old-fashioned multi-psky handling
+
     for (i=0; i<8; i++)
         pskyoff[i] = 0;
 
@@ -720,36 +750,24 @@ void ExtLoadMap(const char *mapname)
     switch (sky)
     {
     case MOONSKY1 :
-        //        earth          mountian   mountain         sun
-        pskyoff[6]=1;
-        pskyoff[1]=2;
-        pskyoff[4]=2;
-        pskyoff[2]=3;
+        // keep in sync with MultiPskyInit
+        //                           -v-
+        Bmemcpy(pskyoff, pskymultioff[0], sizeof(pskymultioff[0]));
         break;
 
     case BIGORBIT1 : // orbit
-        //       earth1         2           3           moon/sun
-        pskyoff[5]=1;
-        pskyoff[6]=2;
-        pskyoff[7]=3;
-        pskyoff[2]=4;
+        Bmemcpy(pskyoff, pskymultioff[1], sizeof(pskymultioff[0]));
         break;
 
     case LA : // la city
-        //       earth1         2           3           moon/sun
-        pskyoff[0]=1;
-        pskyoff[1]=2;
-        pskyoff[2]=1;
-        pskyoff[3]=3;
-        pskyoff[4]=4;
-        pskyoff[5]=0;
-        pskyoff[6]=2;
-        pskyoff[7]=3;
+        Bmemcpy(pskyoff, pskymultioff[2], sizeof(pskymultioff[0]));
         break;
     }
 
     pskybits=3;
     parallaxtype=0;
+
+    //////////
     Bsprintf(tempbuf, "Mapster32 - %s",mapname);
 
     map_undoredo_free();
@@ -6544,13 +6562,12 @@ static void Keys3d(void)
                 mouseay=0;
 
                 if (AIMING_AT_CEILING_OR_FLOOR)
-#ifdef YAX_ENABLE
-                if (YAXCHK(yax_getbunch(searchsector, AIMING_AT_FLOOR) < 0))
-#endif
                 {
                     changedir = 1-2*(x1<0);
                     x1 = klabs(x1);
-
+#ifdef YAX_ENABLE
+                    if (yax_getbunch(searchsector, AIMING_AT_FLOOR) < 0)
+#endif
                     while (x1--)
                         AIMED_CEILINGFLOOR(xpanning) = changechar(AIMED_CEILINGFLOOR(xpanning),changedir,0,0);
 
@@ -6764,9 +6781,6 @@ static void Keys3d(void)
             }
             else if (AIMING_AT_CEILING_OR_FLOOR)
             {
-#ifdef YAX_ENABLE
-                if (YAXCHK(yax_getbunch(searchsector, AIMING_AT_FLOOR) < 0))
-#endif
                 {
                     while (updownunits--)
                         AIMED_CEILINGFLOOR(ypanning) = changechar(AIMED_CEILINGFLOOR(ypanning), changedir, smooshyalign, 0);
@@ -6839,6 +6853,8 @@ static void Keys3d(void)
                 tempxrepeat = AIMED_SEL_WALL(xrepeat);
                 tempxrepeat = max(1, tempxrepeat);
                 tempyrepeat = AIMED_SEL_WALL(yrepeat);
+                tempxpanning = AIMED_SEL_WALL(xpanning);
+                tempypanning = AIMED_SEL_WALL(ypanning);
                 tempcstat = AIMED_SEL_WALL(cstat) & ~YAX_NEXTWALLBITS;
                 templenrepquot = getlenbyrep(wallength(searchwall), tempxrepeat);
             }
@@ -6850,7 +6866,7 @@ static void Keys3d(void)
                 tempyrepeat = AIMED_CEILINGFLOOR(ypanning);
 #ifdef YAX_ENABLE
                 if (yax_getbunch(searchsector, AIMING_AT_FLOOR) >= 0)
-                    tempxrepeat = tempyrepeat = 0;
+                    tempxrepeat = 0;
 #endif
                 tempcstat = AIMED_CEILINGFLOOR(stat) & ~YAX_BIT;
             }
@@ -6954,8 +6970,12 @@ static void Keys3d(void)
                 {
                     wall[i].xrepeat = tempxrepeat;
                     wall[i].yrepeat = tempyrepeat;
-                    wall[i].cstat &= YAX_NEXTWALLBITS;
-                    wall[i].cstat |= (tempcstat & ~YAX_NEXTWALLBITS);
+
+                    wall[i].xpanning = tempxpanning;
+                    wall[i].ypanning = tempypanning;
+                    wall[i].cstat &= ~(4+8+256);
+                    wall[i].cstat |= (tempcstat & (4+8+256));
+
                     fixxrepeat(i, templenrepquot);
                 }
 
@@ -7051,6 +7071,10 @@ static void Keys3d(void)
             {
                 wall[searchwall].xrepeat = tempxrepeat;
                 wall[searchwall].yrepeat = tempyrepeat;
+                wall[searchwall].xpanning = tempxpanning;
+                wall[searchwall].ypanning = tempypanning;
+                wall[searchwall].cstat &= (4+8+256);
+                wall[searchwall].cstat |= (tempcstat & (4+8+256));
 
                 SET_PROTECT_BITS(wall[searchwall].cstat, tempcstat, YAX_NEXTWALLBITS);
 
@@ -7101,11 +7125,8 @@ paste_ceiling_or_floor:
 #ifdef YAX_ENABLE
                     if (yax_getbunch(searchsector, AIMING_AT_FLOOR) < 0)
 #endif
-                    {
                         AIMED_CEILINGFLOOR(xpanning) = tempxrepeat;
-                        AIMED_CEILINGFLOOR(ypanning) = tempyrepeat;
-                    }
-
+                    AIMED_CEILINGFLOOR(ypanning) = tempyrepeat;
                     SET_PROTECT_BITS(AIMED_CEILINGFLOOR(stat), tempcstat, YAX_BIT);
 
                     sector[searchsector].visibility = tempvis;
@@ -7228,10 +7249,8 @@ paste_ceiling_or_floor:
             j = yax_getbunch(searchsector, AIMING_AT_FLOOR);
             if (j < 0)
 #endif
-            {
                 AIMED_CEILINGFLOOR(xpanning) = 0;
-                AIMED_CEILINGFLOOR(ypanning) = 0;
-            }
+            AIMED_CEILINGFLOOR(ypanning) = 0;
             AIMED_CEILINGFLOOR(stat) &= ~2;
             AIMED_CEILINGFLOOR(heinum) = 0;
 #ifdef YAX_ENABLE
@@ -7758,13 +7777,15 @@ static void Keys2d(void)
         {
             for (i=0; i<numsectors; i++)
                 if (inside_editor(&pos, searchx,searchy, zoom, mousxplc,mousyplc,i) == 1)
-#ifdef YAX_ENABLE
-                if (yax_getbunch(i, YAX_FLOOR) < 0)
-#endif
                 {
-                    sector[i].floorxpanning = sector[i].floorypanning = 0;
+#ifdef YAX_ENABLE
+                    if (yax_getbunch(i, YAX_FLOOR) < 0)
+#endif
+                        sector[i].floorxpanning = 0;
+                    sector[i].floorypanning = 0;
                     message("Sector %d floor panning reset", i);
                     asksave = 1;
+                    break;
                 }
         }
     }
@@ -7795,7 +7816,7 @@ static void Keys2d(void)
                 {
                     for (i=0; i<numsectors; i++)
 #ifdef YAX_ENABLE
-                        if (yax_getbunch(i, YAX_FLOOR) < 0)
+                        if (k==1 || yax_getbunch(i, YAX_FLOOR) < 0)
 #endif
                         if (inside_editor(&pos, searchx,searchy, zoom, mousxplc,mousyplc,i) == 1)
                         {
@@ -8395,6 +8416,12 @@ static void G_CheckCommandLine(int32_t argc, const char **argv)
                     i++;
                     continue;
                 }
+                if (!Bstrcasecmp(c+1,"-nm") || Bstrcasecmp(c+1,"-ns"))
+                {
+                    COPYARG(i);
+                    i++;
+                    continue;
+                }
                 if (!Bstrcasecmp(c+1,"ww2gi"))
                 {
                     Bstrcpy(g_grpNamePtr, "ww2gi.grp");
@@ -10164,6 +10191,8 @@ int32_t ExtInit(void)
 
     ReadHelpFile("m32help.hlp");
 
+    MultiPskyInit();
+
     signal(SIGINT, m32script_interrupt_handler);
 
     return rv;
@@ -11098,7 +11127,31 @@ int32_t CheckMapCorruption(int32_t printfromlev, uint64_t tryfixing)
                                     if (wall[jp2].x != wall[ynwp2].x || wall[jp2].y != wall[ynwp2].y)
                                         CORRUPTCHK_PRINT(4, CORRUPT_WALL|j, "WALL %d's and its YAX-NEXTWALL(%d)=%d's p2-coordinates not equal",
                                                          j, cf, ynw);
-                                }
+                                    else
+                                    {
+                                        int32_t onumct = numcorruptthings;
+                                        ynwp2 = yax_getnextwall(ynw, !cf);
+                                        if (ynwp2 != j)
+                                        {
+                                            CORRUPTCHK_PRINT(4, CORRUPT_WALL|j, "WALL %d's YAX-NEXTWALL(%d)=%d's reverse link wrong"
+                                                             " (expected %d, have %d)", j, cf, ynw, j, ynwp2);
+                                            if (onumct < MAXCORRUPTTHINGS)
+                                            {
+                                                if (tryfixing & (1ull<<onumct))
+                                                {
+                                                    yax_setnextwall(ynw, !cf, j);
+                                                    OSD_Printf(CCHK_CORRECTED "auto-correction: set wall %d's yax-nextwall(%d)=%d's yax-nextwall(%d) to %d\n",
+                                                               j, cf, ynw, !cf, j);
+                                                }
+                                                else if (4>=printfromlev)
+                                                {
+                                                    OSD_Printf("   will set wall %d's yax-nextwall(%d)=%d's yax-nextwall(%d) to %d on tryfix\n",
+                                                               j, cf, ynw, !cf, j);
+                                                }
+                                            }
+                                        }
+                                    }
+                                }   // woot!
                             }
                         }
                     }
diff --git a/polymer/eduke32/source/duke3d.h b/polymer/eduke32/source/duke3d.h
index 5c2decf70..b65a980b2 100644
--- a/polymer/eduke32/source/duke3d.h
+++ b/polymer/eduke32/source/duke3d.h
@@ -64,7 +64,13 @@ extern "C" {
 #define WW2GI               (g_gameType & GAME_WW2)
 
 // increase by 3, because atomic GRP adds 1, and Shareware adds 2
-#define BYTEVERSION_JF      198
+#ifdef YAX_ENABLE
+// we'll have to introduce a BYTEVERSION2 sooner or later anyway...:
+# define BYTEVERSION_JF      228
+//            keep in sync?  v^v
+#else
+# define BYTEVERSION_JF      198
+#endif
 #define BYTEVERSION_13      27
 #define BYTEVERSION_14      116
 #define BYTEVERSION_15      117
diff --git a/polymer/eduke32/source/game.c b/polymer/eduke32/source/game.c
index 5302e226e..36f0e56cd 100644
--- a/polymer/eduke32/source/game.c
+++ b/polymer/eduke32/source/game.c
@@ -3212,9 +3212,9 @@ void G_SE40(int32_t smoothratio)
     }
 }
 
-static int32_t g_yax_smoothratio;
+int32_t g_yax_smoothratio;
 #ifdef YAX_ENABLE
-static void G_AnalyzeSprites(void)
+void G_AnalyzeSprites(void)
 {
     G_DoSpriteAnimations(ud.camera.x,ud.camera.y,ud.cameraang,g_yax_smoothratio);
 }
@@ -3419,11 +3419,22 @@ void G_DrawRooms(int32_t snum, int32_t smoothratio)
         {
             getzsofslope(ud.camerasect,ud.camera.x,ud.camera.y,&cz,&fz);
 #ifdef YAX_ENABLE
-            if (yax_getbunch(ud.camerasect, YAX_CEILING) < 0)
+            if (yax_getbunch(ud.camerasect, YAX_CEILING) >= 0)
+            {
+                if (ud.camera.z < cz)
+                    updatesectorz(ud.camera.x, ud.camera.y, ud.camera.z, &ud.camerasect);
+            }
+            else
 #endif
                 if (ud.camera.z < cz+(4<<8)) ud.camera.z = cz+(4<<8);
+
 #ifdef YAX_ENABLE
-            if (yax_getbunch(ud.camerasect, YAX_FLOOR) < 0)
+            if (yax_getbunch(ud.camerasect, YAX_FLOOR) >= 0)
+            {
+                if (ud.camera.z > fz)
+                    updatesectorz(ud.camera.x, ud.camera.y, ud.camera.z, &ud.camerasect);
+            }
+            else
 #endif
                 if (ud.camera.z > fz-(4<<8)) ud.camera.z = fz-(4<<8);
         }
@@ -3456,7 +3467,10 @@ void G_DrawRooms(int32_t snum, int32_t smoothratio)
                 j = visibility;
                 visibility = (j>>1) + (j>>2);
 
+                yax_preparedrawrooms();
                 drawrooms(tposx,tposy,ud.camera.z,tang,ud.camerahoriz,g_mirrorSector[i]+MAXSECTORS);
+                g_yax_smoothratio = smoothratio;
+                yax_drawrooms(G_AnalyzeSprites, ud.camerahoriz, g_mirrorSector[i]+MAXSECTORS);
 
                 display_mirror = 1;
                 G_DoSpriteAnimations(tposx,tposy,tang,smoothratio);
@@ -6281,8 +6295,10 @@ PALONLY:
             if (actor[i].dispicnum >= 0)
                 actor[i].dispicnum = t->picnum;
         }
-        else if (display_mirror == 1)
-            t->cstat |= 4;
+//        else if (display_mirror == 1)
+//            t->cstat |= 4;
+/* completemirror() already reverses the drawn frame, so the above isn't necessary.
+ * Even Polymost's and Polymer's mirror seems to function correctly this way. */
 
 skip:
         if (g_player[screenpeek].ps->inv_amount[GET_HEATS] > 0 && g_player[screenpeek].ps->heat_on &&
diff --git a/polymer/eduke32/source/game.h b/polymer/eduke32/source/game.h
index 26e226a20..5c8a2b72f 100644
--- a/polymer/eduke32/source/game.h
+++ b/polymer/eduke32/source/game.h
@@ -242,6 +242,8 @@ extern uint8_t *basepaltable[BASEPALCOUNT];
 
 extern user_defs ud;
 
+extern int32_t g_yax_smoothratio;
+
 int32_t A_CheckInventorySprite(spritetype *s);
 int32_t A_InsertSprite(int32_t whatsect,int32_t s_x,int32_t s_y,int32_t s_z,int32_t s_pn,int32_t s_s,int32_t s_xr,int32_t s_yr,int32_t s_a,int32_t s_ve,int32_t s_zv,int32_t s_ow,int32_t s_ss);
 int32_t A_Spawn(int32_t j,int32_t pn);
@@ -282,6 +284,9 @@ void G_HandleLocalKeys(void);
 void G_HandleSpecialKeys(void);
 void G_PrintGameQuotes(void);
 void G_SE40(int32_t smoothratio);
+#ifdef YAX_ENABLE
+void G_AnalyzeSprites(void);
+#endif
 void G_SetCrosshairColor(int32_t r,int32_t g,int32_t b);
 void G_SetStatusBarScale(int32_t sc);
 void G_Shutdown(void);
diff --git a/polymer/eduke32/source/gameexec.c b/polymer/eduke32/source/gameexec.c
index ab0f910da..7c96ceb28 100644
--- a/polymer/eduke32/source/gameexec.c
+++ b/polymer/eduke32/source/gameexec.c
@@ -2335,7 +2335,10 @@ nullquote:
                         j = visibility;
                         visibility = (j>>1) + (j>>2);
 
+                        yax_preparedrawrooms();
                         drawrooms(tposx,tposy,z,tang,horiz,g_mirrorSector[i]+MAXSECTORS);
+                        g_yax_smoothratio = smoothratio;
+                        yax_drawrooms(G_AnalyzeSprites, horiz, g_mirrorSector[i]+MAXSECTORS);
 
                         display_mirror = 1;
                         G_DoSpriteAnimations(tposx,tposy,tang,smoothratio);
diff --git a/polymer/eduke32/source/m32structures.c b/polymer/eduke32/source/m32structures.c
index 05712e5db..6e6bb9f3d 100644
--- a/polymer/eduke32/source/m32structures.c
+++ b/polymer/eduke32/source/m32structures.c
@@ -72,7 +72,11 @@ static int32_t __fastcall VM_AccessWall(int32_t how, int32_t lVar1, int32_t lLab
         case WALL_NEXTWALL: wall[i].nextwall=lValue; break;
         case WALL_NEXTSECTOR: wall[i].nextsector=lValue; break;
         case WALL_CSTAT:
-            wall[i].cstat = lValue&0x03ff;
+            wall[i].cstat = lValue & (0x03ff
+#ifdef YAX_ENABLE
+                                      | (m32_script_expertmode ? YAX_NEXTWALLBITS : 0)
+#endif
+                );
             break;
         case WALL_PICNUM: wall[i].picnum=lValue; break;
         case WALL_OVERPICNUM: wall[i].overpicnum=lValue; break;
diff --git a/polymer/eduke32/source/player.c b/polymer/eduke32/source/player.c
index 0bec4772a..f7b84b307 100644
--- a/polymer/eduke32/source/player.c
+++ b/polymer/eduke32/source/player.c
@@ -5013,6 +5013,9 @@ void P_ProcessInput(int32_t snum)
                     if (j < 0)
                     {
                         if (p->cursectnum >= 0 && sector[p->cursectnum].lotag == 0 && sector[p->cursectnum].hitag == 0)
+#ifdef YAX_ENABLE
+                            if (yax_getbunch(p->cursectnum, YAX_FLOOR) < 0 || (sector[p->cursectnum].floorstat&512))
+#endif
                         {
                             switch (krand()&3)
                             {
@@ -5353,7 +5356,6 @@ HORIZONLY:
         p->pos.x += p->vel.x>>14;
         p->pos.y += p->vel.y>>14;
 #ifdef YAX_ENABLE
-        // TODO: only if ceiling/floor bunchnum >= 0
         updatesectorz(p->pos.x,p->pos.y,p->pos.z,&p->cursectnum);
 #else
         updatesector(p->pos.x,p->pos.y,&p->cursectnum);
@@ -5363,7 +5365,17 @@ HORIZONLY:
     else
     {
 #ifdef YAX_ENABLE
-        updatesectorz(p->pos.x,p->pos.y,p->pos.z,&p->cursectnum);
+        // this updatesectorz conflicts with Duke3d's way of teleporting through water,
+        // so make it a bit conditional... OTOH, this way we have an ugly z jump when
+        // changing from above water to underwater
+        if (p->cursectnum < 0 || !(sector[p->cursectnum].lotag==1 && p->on_ground && yax_getbunch(p->cursectnum, YAX_FLOOR)>=0))
+        {
+            // Do updatesectorz only if ceiling/floor bunchnum is >= 0. Otherwise, unwanted
+            // side-effects like dying when jumping into a lotag==1 sector can occur.
+            // The p->jetpack on is there because vel.z 'freezes' when using it
+            if (p->jetpack_on || (p->vel.z && p->cursectnum>=0 && yax_getbunch(p->cursectnum, (p->vel.z>0))>=0))
+                updatesectorz(p->pos.x,p->pos.y,p->pos.z,&p->cursectnum);
+        }
 #endif
         if ((j = clipmove((vec3_t *)p,&p->cursectnum, p->vel.x,p->vel.y,164L,(4L<<8),i,CLIPMASK0)))
             P_CheckTouchDamage(p, j);
diff --git a/polymer/eduke32/source/savegame.c b/polymer/eduke32/source/savegame.c
index f4b57739b..903b2ecbb 100644
--- a/polymer/eduke32/source/savegame.c
+++ b/polymer/eduke32/source/savegame.c
@@ -245,6 +245,19 @@ int32_t G_LoadPlayer(int32_t spot)
     if (kdfread(&wall[0],sizeof(walltype),MAXWALLS,fil) != MAXWALLS) goto corrupt;
     if (kdfread(&numsectors,sizeof(numsectors),1,fil) != 1) goto corrupt;
     if (kdfread(&sector[0],sizeof(sectortype),MAXSECTORS,fil) != MAXSECTORS) goto corrupt;
+
+#ifdef YAX_ENABLE
+    if (kdfread(&numyaxbunches,sizeof(numyaxbunches),1,fil) != 1) goto corrupt;
+    if (numyaxbunches > 0)
+    {
+        if (kdfread(yax_bunchnum,sizeof(yax_bunchnum[0]),numsectors,fil) != numsectors) goto corrupt;
+        if (kdfread(yax_nextwall,sizeof(yax_nextwall[0]),numwalls,fil) != numsectors) goto corrupt;
+        yax_update(2);
+    }
+    else
+        yax_update(1);
+#endif
+
     if (kdfread(&sprite[0],sizeof(spritetype),MAXSPRITES,fil) != MAXSPRITES) goto corrupt;
     if (kdfread(&spriteext[0],sizeof(spriteext_t),MAXSPRITES,fil) != MAXSPRITES) goto corrupt;
 
@@ -678,6 +691,16 @@ int32_t G_SavePlayer(int32_t spot)
     dfwrite(&wall[0],sizeof(walltype),MAXWALLS,fil);
     dfwrite(&numsectors,sizeof(numsectors),1,fil);
     dfwrite(&sector[0],sizeof(sectortype),MAXSECTORS,fil);
+
+#ifdef YAX_ENABLE
+    dfwrite(&numyaxbunches,sizeof(numyaxbunches),1,fil);
+    if (numyaxbunches > 0)
+    {
+        dfwrite(yax_bunchnum,sizeof(yax_bunchnum[0]),numsectors,fil);
+        dfwrite(yax_nextwall,sizeof(yax_nextwall[0]),numwalls,fil);
+    }
+#endif
+
     dfwrite(&sprite[0],sizeof(spritetype),MAXSPRITES,fil);
 #ifdef USE_OPENGL
     for (i=0; i<MAXSPRITES; i++)
@@ -921,7 +944,11 @@ typedef struct dataspec_
     intptr_t cnt;
 } dataspec_t;
 
-#define SV_MAJOR_VER 0
+#ifdef YAX_ENABLE
+# define SV_MAJOR_VER 1
+#else
+# define SV_MAJOR_VER 0
+#endif
 #define SV_MINOR_VER 3
 #define SV_DEFAULTCOMPRTHRES 8
 static uint8_t savegame_diffcompress;  // 0:none, 1:Ken's LZW in cache1d.c
@@ -940,6 +967,7 @@ static uint8_t savegame_comprthres;
 #define DS_LOADFN 128  // .ptr is function that is run when loading
 #define DS_SAVEFN 256  // .ptr is function that is run when saving
 #define DS_NOCHK 1024  // don't check for diffs (and don't write out in dump) since assumed constant throughout demo
+#define DS_PROTECTFN 512
 #define DS_END (0x70000000)
 
 static int32_t ds_getcnt(const dataspec_t *sp)
@@ -1199,7 +1227,7 @@ static void cmpspecdata(const dataspec_t *spec, uint8_t **dumpvar, uint8_t **dif
         if ((sp->flags&(DS_NOCHK|DS_STRING|DS_CMP)))
             continue;
 
-        if (sp->flags&(DS_LOADFN|DS_SAVEFN))
+        if (sp->flags&(DS_LOADFN|DS_SAVEFN) && (sp->flags&(DS_PROTECTFN))==0)
         {
             (*(void ( *)())sp->ptr)();
             continue;
@@ -1347,6 +1375,9 @@ static void sv_postudload();
 static void sv_prespriteextsave();
 static void sv_postspriteext();
 #endif
+#ifdef YAX_ENABLE
+static void sv_postyaxload();
+#endif
 static void sv_calcbitptrsize();
 static void sv_prescriptsave_once();
 static void sv_prescriptload_once();
@@ -1421,6 +1452,12 @@ static const dataspec_t svgm_secwsp[] =
     { DS_NOCHK, &numsectors, sizeof(numsectors), 1 },
     { DS_DYNAMIC|DS_CNT(numsectors), &sector, sizeof(sectortype), (intptr_t)&numsectors },
     { DS_DYNAMIC, &sprite, sizeof(spritetype), MAXSPRITES },
+#ifdef YAX_ENABLE
+    { DS_NOCHK, &numyaxbunches, sizeof(numyaxbunches), 1 },
+    { DS_CNT(numsectors), yax_bunchnum, sizeof(yax_bunchnum[0]), (intptr_t)&numsectors },
+    { DS_CNT(numwalls), yax_nextwall, sizeof(yax_nextwall[0]), (intptr_t)&numwalls },
+    { DS_LOADFN|DS_PROTECTFN, (void *)&sv_postyaxload, 0, 1 },
+#endif
     { 0, &headspritesect[0], sizeof(headspritesect[0]), MAXSECTORS+1 },
     { 0, &prevspritesect[0], sizeof(prevspritesect[0]), MAXSPRITES },
     { 0, &nextspritesect[0], sizeof(nextspritesect[0]), MAXSPRITES },
@@ -1842,6 +1879,13 @@ static void sv_postspriteext()
 }
 #endif
 
+#ifdef YAX_ENABLE
+static void sv_postyaxload()
+{
+    yax_update(numyaxbunches>0 ? 2 : 1);
+}
+#endif
+
 static void sv_calcbitptrsize()
 {
     savegame_bitptrsize = (g_scriptSize+7)>>3;