diff --git a/polymer/eduke32/source/actors.c b/polymer/eduke32/source/actors.c
index 22d9a9b8b..9d6a28b76 100644
--- a/polymer/eduke32/source/actors.c
+++ b/polymer/eduke32/source/actors.c
@@ -409,7 +409,7 @@ static int32_t A_CheckNeedZUpdate(int32_t spritenum, int32_t changez, int32_t *d
     return 0;
 }
 
-int32_t A_MoveSprite(int32_t spritenum, const vec3_t *change, uint32_t cliptype)
+int32_t A_MoveSpriteClipdist(int32_t spritenum, const vec3_t *change, uint32_t cliptype, int32_t clipdist)
 {
     spritetype *const spr = &sprite[spritenum];
     int32_t retval, daz, dozupdate;
@@ -435,9 +435,12 @@ int32_t A_MoveSprite(int32_t spritenum, const vec3_t *change, uint32_t cliptype)
 
     {
         const int32_t oldz=spr->z;
-        int32_t clipdist;
 
-        if (bg)
+        if (clipdist >= 0)
+        {
+            // use that value
+        }
+        else if (bg)
         {
             if (spr->xrepeat > 60)
                 clipdist = 1024;
diff --git a/polymer/eduke32/source/actors.h b/polymer/eduke32/source/actors.h
index f4bd20fce..317772b54 100644
--- a/polymer/eduke32/source/actors.h
+++ b/polymer/eduke32/source/actors.h
@@ -314,7 +314,6 @@ void                A_DoGutsDir(int32_t sp,int32_t gtype,int32_t n);
 int32_t             A_IncurDamage(int32_t sn);
 void                A_MoveCyclers(void);
 void                A_MoveDummyPlayers(void);
-int32_t             A_MoveSprite(int32_t spritenum,const vec3_t *change,uint32_t cliptype);
 void                A_PlayAlertSound(int32_t i);
 void                A_RadiusDamage(int32_t i,int32_t r,int32_t hp1,int32_t hp2,int32_t hp3,int32_t hp4);
 void                A_SpawnMultiple(int32_t sp,int32_t pic,int32_t n);
diff --git a/polymer/eduke32/source/actors_inline.c b/polymer/eduke32/source/actors_inline.c
index 460181bcb..55d626694 100644
--- a/polymer/eduke32/source/actors_inline.c
+++ b/polymer/eduke32/source/actors_inline.c
@@ -38,6 +38,10 @@ ACTOR_INLINE int32_t A_SetSprite(int32_t i,uint32_t cliptype)
     return (A_MoveSprite(i,&davect,cliptype)==0);
 }
 
+ACTOR_INLINE int32_t A_MoveSprite(int32_t spritenum, const vec3_t *change, uint32_t cliptype)
+{
+    return A_MoveSpriteClipdist(spritenum, change, cliptype, -1);
+}
 
 EXTERN_INLINE void G_UpdateInterpolations(void)  //Stick at beginning of G_DoMoveThings
 {
diff --git a/polymer/eduke32/source/actors_inline.h b/polymer/eduke32/source/actors_inline.h
index a08f413df..9a1ec2919 100644
--- a/polymer/eduke32/source/actors_inline.h
+++ b/polymer/eduke32/source/actors_inline.h
@@ -31,7 +31,10 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 # define ACTOR_INLINE_HEADER EXTERN_INLINE_HEADER
 #endif
 
+extern int32_t A_MoveSpriteClipdist(int32_t spritenum, const vec3_t *change, uint32_t cliptype, int32_t clipdist);
+
 ACTOR_INLINE_HEADER int32_t A_SetSprite(int32_t i,uint32_t cliptype);
+ACTOR_INLINE_HEADER int32_t A_MoveSprite(int32_t spritenum, const vec3_t *change, uint32_t cliptype);
 
 EXTERN_INLINE_HEADER void G_UpdateInterpolations(void);
 EXTERN_INLINE_HEADER void G_RestoreInterpolations(void);
diff --git a/polymer/eduke32/source/lunatic/control.lua b/polymer/eduke32/source/lunatic/control.lua
index 6e362329b..0e5a91f04 100644
--- a/polymer/eduke32/source/lunatic/control.lua
+++ b/polymer/eduke32/source/lunatic/control.lua
@@ -1552,7 +1552,7 @@ end
 function _movesprite(spritenum, x, y, z, cliptype)
     check_sprite_idx(spritenum)
     local vel = ivec3(x, y, z)
-    return ffiC.A_MoveSprite(spritenum, vel, cliptype)
+    return ffiC.A_MoveSpriteClipdist(spritenum, vel, cliptype, -1)
 end
 
 -- Also known as A_SetSprite().
@@ -1563,7 +1563,7 @@ function _ssp(i, cliptype)
     local ivec = vec:toivec3()
     ivec.z = spr.zvel
 
-    return (ffiC.A_MoveSprite(i, ivec, cliptype)==0)
+    return (ffiC.A_MoveSpriteClipdist(i, ivec, cliptype, -1)==0)
 end
 
 -- CON's 'setsprite' function on top of the Lunatic-provided ones.
diff --git a/polymer/eduke32/source/lunatic/defs.ilua b/polymer/eduke32/source/lunatic/defs.ilua
index b48054cf0..00154cad1 100644
--- a/polymer/eduke32/source/lunatic/defs.ilua
+++ b/polymer/eduke32/source/lunatic/defs.ilua
@@ -413,6 +413,7 @@ end
 
 --- default defines etc.
 local con_lang = require("con_lang")
+local xmath = require("xmath")
 
 ffi.cdef([[
 typedef struct { int32_t _p; } weaponaccess_t;
@@ -672,7 +673,7 @@ char CheatKeys[2];
 int32_t A_IncurDamage(int32_t sn);  // not bound-checked!
 int32_t G_CheckActivatorMotion(int32_t lotag);
 int32_t A_Dodge(spritetype *s);
-int32_t A_MoveSprite(int32_t spritenum, const vec3_t *change, uint32_t cliptype);
+int32_t A_MoveSpriteClipdist(int32_t spritenum, const vec3_t *change, uint32_t cliptype, int32_t clipdist);
 void P_DoQuote(int32_t q, DukePlayer_t *p);
 void P_SetGamePalette(DukePlayer_t *player, uint8_t palid, int32_t set);
 void G_AddUserQuote(const char *daquote);
@@ -823,6 +824,7 @@ player_static_members._INPUT_EXT_BITS = defs_c.conststruct
 
 local band = bit.band
 local lsh = bit.lshift
+local ivec3 = xmath.ivec3
 
 do
     -- player.all() iterator
@@ -924,6 +926,13 @@ function actor_static_members.fall(i)
     CF.VM_FallSprite(i)
 end
 
+-- actor.move(i, vec, cliptype [, clipdist])
+function actor_static_members.move(i, vec, cliptype, clipdist)
+    check_sprite_idx(i)
+    local vel = ivec3(vec.x, vec.y, vec.z)
+    return ffiC.A_MoveSpriteClipdist(spritenum, vel, cliptype, clipdist or -1)
+end
+
 -- Delete sprite with index <i>.
 function actor_static_members.delete(i)
     check_sprite_idx(i)
@@ -969,15 +978,19 @@ local g_tile = setmtonce({}, defs_c.GenStructMetatable("g_tile", "MAXTILES", til
 -- Among other things, declares struct action and struct move, and their
 -- ID-wrapped types con_action_t and con_move_t
 local con = require("control")
-local isenemytile = con.isenemytile
 
--- Add game-side metamethods to "spritetype" and register it with "metatype"
-local spr_mt_index_add = {
-    isenemy = function(s)
-        return isenemytile(s.picnum)
-    end,
-}
-defs_c.finish_spritetype(spr_mt_index_add)
+do
+    local isenemytile = con.isenemytile
+
+    -- Add game-side metamethods to "spritetype" and register it with "metatype"
+    local spr_mt_index_add = {
+        isenemy = function(s)
+            return isenemytile(s.picnum)
+        end,
+    }
+
+    defs_c.finish_spritetype(spr_mt_index_add)
+end
 
 -- Check a literal numeric action or move value.
 local function check_literal_am(am, typename)
@@ -1600,7 +1613,7 @@ local allowed_modules = {
     engine = require("engine"),
     stat = require("stat"),
     bitar = require("bitar"),
-    xmath = require("xmath"),
+    xmath = xmath,
     fs = require("fs"),
 
     con = con,
@@ -1623,8 +1636,8 @@ do
         return type(v)=="cdata" and ctype_cansave[tonumber(ffi.typeof(v))]
     end
 
-    reg_serializable_cv(allowed_modules.xmath.vec3())
-    reg_serializable_cv(allowed_modules.xmath.ivec3())
+    reg_serializable_cv(xmath.vec3())
+    reg_serializable_cv(ivec3())
 end
 
 -- Protect base modules.
diff --git a/polymer/eduke32/source/lunatic/doc/lunatic.txt b/polymer/eduke32/source/lunatic/doc/lunatic.txt
index 9e96e5187..284704bc9 100644
--- a/polymer/eduke32/source/lunatic/doc/lunatic.txt
+++ b/polymer/eduke32/source/lunatic/doc/lunatic.txt
@@ -790,6 +790,8 @@ claiming them for oneself.
 `wal:set_picnum(tilenum)`, `wal:set_overpicnum(tilenum)`::
 Set the tile number of the wall or its masked portion.
 
+// TODO: the predicates
+
 ===== `wall` static functions
 
 `wall.dragto(i, pos)`::
@@ -947,6 +949,9 @@ _`index_of_spr`_ is the sprite index corresponding to `spr`.  This method is
 provided for convenience, but may be slower than the static function
 `updatesect`.
 
+`spr:isenemy()`::
+*TODO*
+
 ===== `sprite` iterators
 
 +*for* i *in* sprite.all()+::
@@ -1122,6 +1127,9 @@ index. Otherwise, returns *nil*.
 Causes the actor with index `i` to fall in a ``hard-coded'', not further
 specified fashion.
 
+`actor.move(i, vec, cliptype [, clipdist])`::
+*TODO*
+
 [[actor_static_data]]
 ===== `actor` static data
 
diff --git a/polymer/eduke32/source/lunatic/dynsymlist b/polymer/eduke32/source/lunatic/dynsymlist
index 109dc7992..c40905c07 100644
--- a/polymer/eduke32/source/lunatic/dynsymlist
+++ b/polymer/eduke32/source/lunatic/dynsymlist
@@ -211,7 +211,7 @@ rand_jkiss_dbl;
 A_IncurDamage;
 G_CheckActivatorMotion;
 A_Dodge;
-A_MoveSprite;
+A_MoveSpriteClipdist;
 P_DoQuote;
 P_SetGamePalette;
 G_AddUserQuote;