diff --git a/include/SSystem/SComponent/c_bg_s.h b/include/SSystem/SComponent/c_bg_s.h
index 577d0e7af..340820277 100644
--- a/include/SSystem/SComponent/c_bg_s.h
+++ b/include/SSystem/SComponent/c_bg_s.h
@@ -4,7 +4,8 @@
 #include "SSystem/SComponent/c_bg_s_poly_info.h"
 #include "dolphin/types.h"
 
-#define C_BG_INVALID_HEIGHT (-1e+9f)
+#define C_BG_MIN_HEIGHT (-1e+9f)
+#define C_BG_MAX_HEIGHT (1e+9f)
 
 class fopAc_ac_c;
 class cBgS_ShdwDraw;
diff --git a/include/SSystem/SComponent/c_m3d_g_aab.h b/include/SSystem/SComponent/c_m3d_g_aab.h
index 33a936835..8d0b0b1eb 100644
--- a/include/SSystem/SComponent/c_m3d_g_aab.h
+++ b/include/SSystem/SComponent/c_m3d_g_aab.h
@@ -1,6 +1,7 @@
 #ifndef C_M3D_G_AAB_H
 #define C_M3D_G_AAB_H
 
+#include "SSystem/SComponent/c_bg_s.h"
 #include "SSystem/SComponent/c_xyz.h"
 #include "SSystem/SComponent/c_m3d.h"
 #include "SSystem/SComponent/c_m3d_g_lin.h"
@@ -61,8 +62,8 @@ public:
         mMax.x = -1000000000.0f;
     }
     void ClearForMinMaxY() {
-        mMin.y = 1000000000.0f;
-        mMax.y = -1000000000.0f;
+        mMin.y = C_BG_MAX_HEIGHT;
+        mMax.y = C_BG_MIN_HEIGHT;
     }
     void SetMinMaxY(f32 y) {
         if (mMin.y > y) {
diff --git a/include/d/actor/d_a_bomb.h b/include/d/actor/d_a_bomb.h
index 90da2711d..7fc4ca49d 100644
--- a/include/d/actor/d_a_bomb.h
+++ b/include/d/actor/d_a_bomb.h
@@ -1,8 +1,7 @@
 #ifndef D_A_BOMB_H
 #define D_A_BOMB_H
 
-#include "f_op/f_op_actor_mng.h"
-#include "d/d_a_obj.h"
+#include "f_op/f_op_actor.h"
 #include "d/d_particle.h"
 #include "d/d_bg_s_acch.h"
 #include "d/d_cc_d.h"
@@ -178,7 +177,9 @@ private:
     /* 0x2FC */ dBgS_BombAcch mAcch;
     /* 0x4C0 */ dBgS_AcchCir mCir;
     /* 0x500 */ dBgS_ObjGndChk_Yogan mGndChk;
-    /* 0x554 */ cXyz field_0x554;
+    /* 0x554 */ f32 field_0x554;
+    /* 0x558 */ f32 field_0x558;
+    /* 0x55C */ f32 field_0x55C;
     /* 0x560 */ bool field_0x560;
     /* 0x561 */ bool mbWaterIn;
     /* 0x562 */ u8 field_0x562;
diff --git a/include/d/actor/d_a_bomb2.h b/include/d/actor/d_a_bomb2.h
index e7edf60bd..45ab22533 100644
--- a/include/d/actor/d_a_bomb2.h
+++ b/include/d/actor/d_a_bomb2.h
@@ -1,8 +1,7 @@
 #ifndef D_A_BOMB_2_H
 #define D_A_BOMB_2_H
 
-#include "f_op/f_op_actor_mng.h"
-#include "d/d_a_obj.h"
+#include "f_op/f_op_actor.h"
 #include "d/d_particle.h"
 #include "d/d_bg_s_acch.h"
 #include "d/d_cc_d.h"
diff --git a/include/d/d_bg_s.h b/include/d/d_bg_s.h
index eebed39a6..3fbeb322d 100644
--- a/include/d/d_bg_s.h
+++ b/include/d/d_bg_s.h
@@ -121,7 +121,7 @@ public:
         mWallRadius = 0.0f;
         pm_pos = NULL;
         pm_old_pos = NULL;
-        mGroundH = C_BG_INVALID_HEIGHT;
+        mGroundH = C_BG_MIN_HEIGHT;
         field_0x60 = 0;
         field_0x68 = 20.0f;
         field_0x58 = NULL;
diff --git a/include/d/d_com_inf_game.h b/include/d/d_com_inf_game.h
index 3f8025fbe..24625bdaa 100644
--- a/include/d/d_com_inf_game.h
+++ b/include/d/d_com_inf_game.h
@@ -2982,10 +2982,10 @@ int dComIfGd_setShadow(u32 id, s8 param_2, J3DModel* pModel, cXyz* pPos, f32 par
                        s16 rotY = 0, f32 param_12 = 1.0f,
                        GXTexObj* pTexObj = dDlst_shadowControl_c::getSimpleTex());
 
-inline int dComIfGd_setSimpleShadow(cXyz* i_pos, f32 param_1, f32 param_2, cXyz* param_3,
+inline int dComIfGd_setSimpleShadow(cXyz* i_pos, f32 groundY, f32 param_2, cXyz* param_3,
                                     s16 i_angle = 0, f32 param_5 = 1.0f,
                                     GXTexObj* i_tex = dDlst_shadowControl_c::getSimpleTex()) {
-    return g_dComIfG_gameInfo.drawlist.setSimpleShadow(i_pos, param_1, param_2, param_3, i_angle,
+    return g_dComIfG_gameInfo.drawlist.setSimpleShadow(i_pos, groundY, param_2, param_3, i_angle,
                                                        param_5, i_tex);
 }
 
diff --git a/include/d/d_drawlist.h b/include/d/d_drawlist.h
index d5ddc38e6..56a5bb268 100644
--- a/include/d/d_drawlist.h
+++ b/include/d/d_drawlist.h
@@ -551,9 +551,9 @@ public:
     void drawXluListInvisible() { drawXluDrawList(mpXluListInvisible); }
     void drawOpaList2D() { drawOpaDrawList(mpOpaList2D); }
 
-    int setSimpleShadow(cXyz* i_pos, f32 param_1, f32 param_2, cXyz* param_3, s16 i_angle,
+    int setSimpleShadow(cXyz* i_pos, f32 groundY, f32 param_2, cXyz* param_3, s16 i_angle,
                         f32 param_5, GXTexObj* i_tex) {
-        return mShadowControl.setSimple(i_pos, param_1, param_2, param_3, i_angle, param_5,
+        return mShadowControl.setSimple(i_pos, groundY, param_2, param_3, i_angle, param_5,
                                         i_tex);
     }
     int setRealShadow(u32 id, s8 param_2, J3DModel* pModel, cXyz* pPos, f32 param_5, f32 param_6,
diff --git a/src/SSystem/SComponent/c_bg_s.cpp b/src/SSystem/SComponent/c_bg_s.cpp
index b2e3ffc6e..83836432a 100644
--- a/src/SSystem/SComponent/c_bg_s.cpp
+++ b/src/SSystem/SComponent/c_bg_s.cpp
@@ -128,7 +128,7 @@ bool cBgS::LineCross(cBgS_LinChk* chk) {
 
 /* 802468E4-80246A14       .text GroundCross__4cBgSFP11cBgS_GndChk */
 f32 cBgS::GroundCross(cBgS_GndChk* chk) {
-    chk->SetNowY(C_BG_INVALID_HEIGHT);
+    chk->SetNowY(C_BG_MIN_HEIGHT);
     chk->ClearPi();
     chk->mWallPrecheck = (chk->mFlag & 0x02);
     chk->mGndPrecheck = (chk->mFlag & 0x01);
diff --git a/src/SSystem/SComponent/c_m3d_g_aab.cpp b/src/SSystem/SComponent/c_m3d_g_aab.cpp
index 80d2519b0..1d89a2434 100644
--- a/src/SSystem/SComponent/c_m3d_g_aab.cpp
+++ b/src/SSystem/SComponent/c_m3d_g_aab.cpp
@@ -4,7 +4,6 @@
 //
 
 #include "SSystem/SComponent/c_m3d_g_aab.h"
-#include "dolphin/types.h"
 
 /* 80251CC4-80251D08       .text SetMinMax__8cM3dGAabFRC4cXyz */
 void cM3dGAab::SetMinMax(const cXyz& pMinMax) {
diff --git a/src/d/actor/d_a_agb.cpp b/src/d/actor/d_a_agb.cpp
index e8ee08b5e..2387c76a4 100644
--- a/src/d/actor/d_a_agb.cpp
+++ b/src/d/actor/d_a_agb.cpp
@@ -1310,7 +1310,7 @@ void daAgb_c::CursorMove(fopAc_ac_c* actor, u32 stage_type) {
     
     cXyz r1_14;
     dBgS_GndChk r1_5C;
-    f32 f30 = C_BG_INVALID_HEIGHT;
+    f32 f30 = C_BG_MIN_HEIGHT;
     r1_5C.OffWall();
     r1_14.y = actor->current.pos.y + 150.0f;
     static cXy l_ckOffset[] = {
diff --git a/src/d/actor/d_a_am2.cpp b/src/d/actor/d_a_am2.cpp
index 01948b4cc..adb58c791 100644
--- a/src/d/actor/d_a_am2.cpp
+++ b/src/d/actor/d_a_am2.cpp
@@ -387,7 +387,7 @@ static BOOL Line_check(am2_class* i_this, cXyz destPos) {
 /* 0000177C-00001A24       .text naraku_check__FP9am2_class */
 static BOOL naraku_check(am2_class* i_this) {
     // Checks if the Armos has fallen into an abyss.
-    if (i_this->mAcch.GetGroundH() != -1000000000.0f &&
+    if (i_this->mAcch.GetGroundH() != C_BG_MIN_HEIGHT &&
         dComIfG_Bgsp()->ChkPolySafe(i_this->mAcch.m_gnd) &&
         dComIfG_Bgsp()->GetGroundCode(i_this->mAcch.m_gnd) == 4) // Abyss ground code
     {
diff --git a/src/d/actor/d_a_arrow.cpp b/src/d/actor/d_a_arrow.cpp
index d6ba1b183..c3ffce425 100644
--- a/src/d/actor/d_a_arrow.cpp
+++ b/src/d/actor/d_a_arrow.cpp
@@ -514,7 +514,7 @@ void daArrow_c::setRoomInfo() {
     
     mGndChk.SetPos(&current.pos);
     f32 groundY = dComIfG_Bgsp()->GroundCross(&mGndChk);
-    if (groundY != -1000000000.0f) {
+    if (groundY != C_BG_MIN_HEIGHT) {
         roomNo = dComIfG_Bgsp()->GetRoomId(mGndChk);
         tevStr.mEnvrIdxOverride = dComIfG_Bgsp()->GetPolyColor(mGndChk);
     } else {
diff --git a/src/d/actor/d_a_bk.cpp b/src/d/actor/d_a_bk.cpp
index e8081a6b8..fd42d11ec 100644
--- a/src/d/actor/d_a_bk.cpp
+++ b/src/d/actor/d_a_bk.cpp
@@ -625,8 +625,8 @@ static u8 ground_4_check(bk_class* i_this, int r18, s16 r20, f32 f29) {
         sp8 += i_this->current.pos;
         gndChk.SetPos(&sp8);
         sp8.y = dComIfG_Bgsp()->GroundCross(&gndChk);
-        if (sp8.y == -1e9f) {
-            sp8.y = 1e9f;
+        if (sp8.y == C_BG_MIN_HEIGHT) {
+            sp8.y = C_BG_MAX_HEIGHT;
         }
         if (i_this->dr.mAcch.GetGroundH() - sp8.y > 200.0f) {
             r19 |= check_bit[i];
@@ -3225,14 +3225,14 @@ static BOOL daBk_Execute(bk_class* i_this) {
         sp28.y += 50.0f - i_this->dr.m44C.y;
         gndChk.SetPos(&sp28);
         sp28.y = dComIfG_Bgsp()->GroundCross(&gndChk);
-        if (sp28.y != -1e9f) {
+        if (sp28.y != C_BG_MIN_HEIGHT) {
             Vec temp;
             temp.x = sp28.x;
             temp.y = 50.0f + sp28.y;
             temp.z = sp28.z + f31;
             gndChk.SetPos(&temp);
             f32 f1 = dComIfG_Bgsp()->GroundCross(&gndChk);
-            if (f1 != -1e9f) {
+            if (f1 != C_BG_MIN_HEIGHT) {
                 r21 = (s16)-cM_atan2s(f1 - sp28.y, temp.z - sp28.z);
                 if (r21 > 0x2000 || r21 < -0x2000) {
                     r21 = 0;
@@ -3243,7 +3243,7 @@ static BOOL daBk_Execute(bk_class* i_this) {
             temp.z = sp28.z;
             gndChk.SetPos(&temp);
             f1 = dComIfG_Bgsp()->GroundCross(&gndChk);
-            if (f1 != -1e9f) {
+            if (f1 != C_BG_MIN_HEIGHT) {
                 r23 = (s16)cM_atan2s(f1 - sp28.y, temp.x - sp28.x);
                 if (r23 > 0x2000 || r23 < -0x2000) {
                     r23 = 0;
diff --git a/src/d/actor/d_a_boko.cpp b/src/d/actor/d_a_boko.cpp
index fc594d802..4d2b79af6 100644
--- a/src/d/actor/d_a_boko.cpp
+++ b/src/d/actor/d_a_boko.cpp
@@ -69,7 +69,7 @@ void daBoko_c::setFlameEffect() {
 /* 00001340-000013CC       .text setRoomInfo__8daBoko_cFv */
 void daBoko_c::setRoomInfo() {
     int roomNo;
-    if (mAcch.GetGroundH() != -1e9f) {
+    if (mAcch.GetGroundH() != C_BG_MIN_HEIGHT) {
         roomNo = dComIfG_Bgsp()->GetRoomId(mAcch.m_gnd);
         tevStr.mEnvrIdxOverride = dComIfG_Bgsp()->GetPolyColor(mAcch.m_gnd);
     } else {
@@ -194,7 +194,7 @@ BOOL daBoko_c::procCarry() {
             int i;
             for (i = 0; i < 3; i++) {
                 m_ground_check.SetPos(&current.pos);
-                if (dComIfG_Bgsp()->GroundCross(&m_ground_check) != -1e9f) {
+                if (dComIfG_Bgsp()->GroundCross(&m_ground_check) != C_BG_MIN_HEIGHT) {
                     break;
                 }
                 current.pos.x -= 50.0f * cM_ssin(shape_angle.y);
diff --git a/src/d/actor/d_a_bomb2.cpp b/src/d/actor/d_a_bomb2.cpp
index 9f51e2356..734cc1a62 100644
--- a/src/d/actor/d_a_bomb2.cpp
+++ b/src/d/actor/d_a_bomb2.cpp
@@ -6,6 +6,7 @@
 #include "d/actor/d_a_bomb2.h"
 #include "d/actor/d_a_sea.h"
 #include "d/actor/d_a_player.h"
+#include "d/d_a_obj.h"
 #include "d/d_procname.h"
 #include "d/d_kankyo_wether.h"
 #include "d/d_com_inf_game.h"
@@ -292,12 +293,12 @@ namespace daBomb2 {
         mAcch.ClrRoofNone();
         mAcch.m_roof_crr_height = 50.0f;
         mAcch.OnLineCheck();
-        field_0x51C = -1.0e9f;
-        field_0x520 = -1.0e9f;
+        field_0x51C = C_BG_MIN_HEIGHT;
+        field_0x520 = C_BG_MIN_HEIGHT;
         field_0x524 = 0;
         mbWaterIn = 0;
         field_0x526 = 0;
-        field_0x528 = -1.0e9f;
+        field_0x528 = C_BG_MIN_HEIGHT;
     }
 
     dCcD_SrcSph Act_c::M_sph_src = {
@@ -553,7 +554,7 @@ namespace daBomb2 {
             r5 = true;
             field_0x526 = 1;
         } else {
-            field_0x520 = -1e9f;
+            field_0x520 = C_BG_MIN_HEIGHT;
             field_0x526 = 0;
         }
         mbWaterIn = r5;
@@ -564,7 +565,7 @@ namespace daBomb2 {
     }
 
     bool Act_c::chk_lava_in() const {
-        if(field_0x51C == -1.0e9f) {
+        if(field_0x51C == C_BG_MIN_HEIGHT) {
             return false;
         }
 
@@ -573,7 +574,7 @@ namespace daBomb2 {
 
     void Act_c::setRoomInfo() {
         s32 roomNo;
-        if(mAcch.GetGroundH() != -1.0e9f) {
+        if(mAcch.GetGroundH() != C_BG_MIN_HEIGHT) {
             roomNo = dComIfG_Bgsp()->GetRoomId(mAcch.m_gnd);
             tevStr.mEnvrIdxOverride = dComIfG_Bgsp()->GetPolyColor(mAcch.m_gnd);
         }
@@ -1092,7 +1093,7 @@ namespace daBomb2 {
     void Act_c::mode_sink() {
         f32 temp;
         bool temp2 = fopAcM_getWaterY(&current.pos, &temp);
-        if(temp2 && field_0x528 != -1.0e9f && --field_0x698 > 0) {
+        if(temp2 && field_0x528 != C_BG_MIN_HEIGHT && --field_0x698 > 0) {
             current.pos.y += temp - field_0x528;
             field_0x528 = temp;
             posMoveF();
diff --git a/src/d/actor/d_a_bomb3.inc b/src/d/actor/d_a_bomb3.inc
index cbcead242..6ce3a9866 100644
--- a/src/d/actor/d_a_bomb3.inc
+++ b/src/d/actor/d_a_bomb3.inc
@@ -4,6 +4,7 @@
 
 #include "d/actor/d_a_bomb.h"
 #include "SSystem/SComponent/c_counter.h"
+#include "d/d_a_obj.h"
 #include "d/d_com_inf_game.h"
 #include "d/d_procname.h"
 #include "d/actor/d_a_player_main.h"
@@ -198,7 +199,7 @@ BOOL daBomb_c::draw() {
         draw_norm();
     }
 
-    if(fopAcM_GetModel(this) == 0 && mAcch.GetGroundH() != -1.0e9f) {
+    if(fopAcM_GetModel(this) == 0 && mAcch.GetGroundH() != C_BG_MIN_HEIGHT) {
         cM3dGPla* pNormal = dComIfG_Bgsp()->GetTriPla(mAcch.m_gnd);
         if(pNormal) {
             dComIfGd_setSimpleShadow(&current.pos, mAcch.GetGroundH(), 25.0f, pNormal->GetNP());
@@ -439,8 +440,8 @@ bool daBomb_c::checkExplodeBg() {
 /* 800DA320-800DA3A0       .text water_tention__8daBomb_cFv */
 void daBomb_c::water_tention() {
     if(chk_water_in()) {
-        if(field_0x554.y != -1.0e9f && field_0x554.z != -1.0e9f) {
-            f32 temp = field_0x554.y - field_0x554.z;
+        if(field_0x558 != C_BG_MIN_HEIGHT && field_0x55C != C_BG_MIN_HEIGHT) {
+            f32 temp = field_0x558 - field_0x55C;
             current.pos.y += temp < 0.0f ? 0.8f * temp : 0.2f * temp;
         }
     }
@@ -506,7 +507,7 @@ void daBomb_c::bgCrrPos_lava() {
     cXyz temp(current.pos.x, old.pos.y + 1.0f, current.pos.z);
     mGndChk.SetPos(&temp);
 
-    field_0x554.x = dComIfG_Bgsp()->GroundCross(&mGndChk);
+    field_0x554 = dComIfG_Bgsp()->GroundCross(&mGndChk);
 }
 
 /* 800DA5E0-800DA700       .text bgCrrPos_water__8daBomb_cFv */
@@ -517,7 +518,7 @@ void daBomb_c::bgCrrPos_water() {
     bool r4 = mAcch.ChkWaterIn();
     bool r3 = r31 && current.pos.y < f1;
     bool r5 = false;
-    field_0x554.z = field_0x554.y;
+    field_0x55C = field_0x558;
     if (r4 && r3) {
         if (f31 > f1) {
             r3 = 0;
@@ -526,15 +527,15 @@ void daBomb_c::bgCrrPos_water() {
         }
     }
     if (r4) {
-        field_0x554.y = f31;
+        field_0x558 = f31;
         r5 = true;
         field_0x562 = 0;
     } else if (r3) {
-        field_0x554.y = f1;
+        field_0x558 = f1;
         r5 = true;
         field_0x562 = 1;
     } else {
-        field_0x554.y = -1e9f;
+        field_0x558 = C_BG_MIN_HEIGHT;
         field_0x562 = 0;
     }
     field_0x560 = r5 && !mbWaterIn;
@@ -555,21 +556,21 @@ bool daBomb_c::chk_water_in() {
 bool daBomb_c::chk_water_sink() {
     bool water = chk_water_in();
 
-    return water && field_0x554.y - current.pos.y > 30.0f;
+    return water && field_0x558 - current.pos.y > 30.0f;
 }
 
 /* 800DA768-800DA794       .text chk_lava_hit__8daBomb_cFv */
 bool daBomb_c::chk_lava_hit() {
-    if(field_0x554.x == -1.0e9f) {
+    if(field_0x554 == C_BG_MIN_HEIGHT) {
         return false;
     }
 
-    return current.pos.y < field_0x554.x;
+    return current.pos.y < field_0x554;
 }
 
 /* 800DA794-800DA7CC       .text chk_dead_zone__8daBomb_cFv */
 bool daBomb_c::chk_dead_zone() {
-    return mAcch.GetGroundH() == -1.0e9f && field_0x554.y == -1.0e9f && field_0x554.x == -1.0e9f;
+    return mAcch.GetGroundH() == C_BG_MIN_HEIGHT && field_0x558 == C_BG_MIN_HEIGHT && field_0x554 == C_BG_MIN_HEIGHT;
 }
 
 /* 800DA7CC-800DA8C8       .text bound__8daBomb_cFf */
@@ -630,7 +631,7 @@ void daBomb_c::set_real_shadow_flag() {
 /* 800DA9DC-800DAA60       .text setRoomInfo__8daBomb_cFv */
 void daBomb_c::setRoomInfo() {
     s32 roomNo;
-    if(mAcch.GetGroundH() != -1.0e9f) {
+    if(mAcch.GetGroundH() != C_BG_MIN_HEIGHT) {
         roomNo = dComIfG_Bgsp()->GetRoomId(mAcch.m_gnd);
         tevStr.mEnvrIdxOverride = dComIfG_Bgsp()->GetPolyColor(mAcch.m_gnd);
     }
@@ -1210,7 +1211,7 @@ void daBomb_c::se_cannon_fly_stop() {
 
 /* 800DC44C-800DC568       .text eff_water_splash__8daBomb_cFv */
 void daBomb_c::eff_water_splash() {
-    cXyz pos(current.pos.x, field_0x554.y, current.pos.z);
+    cXyz pos(current.pos.x, field_0x558, current.pos.z);
     fopKyM_createWpillar(&pos, 0.5f, 0.75f, 0);
 
     cBgS_PolyInfo* temp[2] = {
@@ -1399,7 +1400,9 @@ void daBomb_c::create_init() {
     mAcch.m_roof_crr_height = 50.0f;
     mAcch.OnLineCheck();
 
-    field_0x554.setall(-1.0e9f);
+    field_0x554 = C_BG_MIN_HEIGHT;
+    field_0x558 = C_BG_MIN_HEIGHT;
+    field_0x55C = C_BG_MIN_HEIGHT;
     field_0x560 = 0;
     mbWaterIn = 0;
     field_0x562 = 0;
diff --git a/src/d/actor/d_a_esa.cpp b/src/d/actor/d_a_esa.cpp
index 689c2e021..ae80f8ce5 100644
--- a/src/d/actor/d_a_esa.cpp
+++ b/src/d/actor/d_a_esa.cpp
@@ -51,7 +51,7 @@ void bg_check(esa_class* i_this) {
     cXyz sp54 = i_this->current.pos;
     sp54.y += 100.0f;
     f32 waterHeight = dBgS_GetWaterHeight(sp54);
-    if(waterHeight != -1000000000.0f && i_this->mGroundHeight <= waterHeight) {
+    if(waterHeight != C_BG_MIN_HEIGHT && i_this->mGroundHeight <= waterHeight) {
         i_this->mGroundHeight = waterHeight;
         state = 2;
     }
diff --git a/src/d/actor/d_a_ib.cpp b/src/d/actor/d_a_ib.cpp
index 1da550291..017f8c2ed 100644
--- a/src/d/actor/d_a_ib.cpp
+++ b/src/d/actor/d_a_ib.cpp
@@ -201,19 +201,19 @@ void daIball_c::checkGeo() {
     
     (this->*mode_proc[mMode])();
     
-    dBgS_ObjGndChk_Yogan gnd_chk;
+    dBgS_ObjGndChk_Yogan lavaChk;
     cXyz pos(current.pos.x, old.pos.y + 30.0f + m_data.mYOffset, current.pos.z);
-    gnd_chk.SetPos(&pos);
-    f32 groundY = dComIfG_Bgsp()->GroundCross(&gnd_chk);
+    lavaChk.SetPos(&pos);
+    f32 lavaY = dComIfG_Bgsp()->GroundCross(&lavaChk);
     f32 groundH = mAcch.GetGroundH();
-    if (groundY != -1000000000.0f) {
-        f32 dist_off_gnd = groundY - groundH;
-        if ((dist_off_gnd < 20.0f && groundY > current.pos.y) || (dist_off_gnd >= 20.0f && groundY > current.pos.y + 20.0f)) {
+    if (lavaY != C_BG_MIN_HEIGHT) {
+        f32 lava_depth = lavaY - groundH;
+        if ((lava_depth < 20.0f && lavaY > current.pos.y) || (lava_depth >= 20.0f && lavaY > current.pos.y + 20.0f)) {
             fopAcM_seStartCurrent(this, JA_SE_OBJ_FALL_MAGMA_S, 0);
             cXyz particle_scale;
             particle_scale.setall(0.25f);
             cXyz particle_pos(current.pos);
-            particle_pos.y = groundY;
+            particle_pos.y = lavaY;
             dComIfGp_particle_set(dPa_name::ID_SCENE_80D5, &particle_pos, NULL, &particle_scale);
             fopAcM_delete(this);
         }
@@ -238,7 +238,7 @@ void daIball_c::mode_wait() {
     }
     
     f32 seaHeight = mAcch.GetSeaHeight();
-    if (seaHeight > current.pos.y && seaHeight != -1000000000.0f) {
+    if (seaHeight > current.pos.y && seaHeight != C_BG_MIN_HEIGHT) {
         mode_water_init();
         current.pos.y = seaHeight;
     }
@@ -254,10 +254,10 @@ void daIball_c::mode_water_init() {
 /* 800F3FE8-800F4054       .text mode_water__9daIball_cFv */
 void daIball_c::mode_water() {
     f32 seaHeight = mAcch.GetSeaHeight();
-    if (seaHeight == -1000000000.0f || seaHeight < current.pos.y) {
+    if (seaHeight == C_BG_MIN_HEIGHT || seaHeight < current.pos.y) {
         mode_wait_init();
     }
-    if (seaHeight != -1000000000.0f) {
+    if (seaHeight != C_BG_MIN_HEIGHT) {
         current.pos.y = seaHeight;
     }
 }
diff --git a/src/d/actor/d_a_item.cpp b/src/d/actor/d_a_item.cpp
index 2cc266cbc..abc7af9ae 100644
--- a/src/d/actor/d_a_item.cpp
+++ b/src/d/actor/d_a_item.cpp
@@ -1296,12 +1296,12 @@ void daItem_c::mode_wait() {
         mode_water_init();
     }
     
-    dBgS_ObjGndChk_Yogan gndChk;
+    dBgS_ObjGndChk_Yogan lavaChk;
     cXyz temp;
     temp.set(old.pos.x, old.pos.y, old.pos.z);
-    gndChk.SetPos(&temp);
-    f32 groundY = dComIfG_Bgsp()->GroundCross(&gndChk);
-    if (groundY != -1000000000.0f && groundY > current.pos.y) {
+    lavaChk.SetPos(&temp);
+    f32 lavaY = dComIfG_Bgsp()->GroundCross(&lavaChk);
+    if (lavaY != C_BG_MIN_HEIGHT && lavaY > current.pos.y) {
         fopAcM_delete(this);
     }
 }
diff --git a/src/d/actor/d_a_kt.cpp b/src/d/actor/d_a_kt.cpp
index e06022a6b..0b43fe787 100644
--- a/src/d/actor/d_a_kt.cpp
+++ b/src/d/actor/d_a_kt.cpp
@@ -100,7 +100,7 @@ void kotori_move(kt_class* i_this) {
 
             gndChk.SetPos(&i_this->mTargetPosHome);
             i_this->mTargetPosHome.y = dComIfG_Bgsp()->GroundCross(&gndChk);
-            if (i_this->mTargetPosHome.y == -1e9f)
+            if (i_this->mTargetPosHome.y == C_BG_MIN_HEIGHT)
                 i_this->mTargetPosHome = player->current.pos;
             i_this->mTargetPos = i_this->mTargetPosHome;
             i_this->mSpeedLerp = 0.0f;
diff --git a/src/d/actor/d_a_leaflift.cpp b/src/d/actor/d_a_leaflift.cpp
index 60732b718..5e851374b 100644
--- a/src/d/actor/d_a_leaflift.cpp
+++ b/src/d/actor/d_a_leaflift.cpp
@@ -112,7 +112,7 @@ void daLlift_c::CreateInit() {
     cXyz waterCheckPos = current.pos;
     waterCheckPos.y += 200.0f;
     mWaterY = dBgS_ObjGndChk_Wtr_Func(waterCheckPos);
-    if (mWaterY != -1e9f) {
+    if (mWaterY != C_BG_MIN_HEIGHT) {
         cXyz particlePos = current.pos;
         particlePos.y = mWaterY + 1.0f; 
         mEmitter3 = dComIfGp_particle_set(dPa_name::ID_SCENE_82AA, &particlePos, &current.angle);
diff --git a/src/d/actor/d_a_nh.cpp b/src/d/actor/d_a_nh.cpp
index 43e865788..3ac7c7355 100644
--- a/src/d/actor/d_a_nh.cpp
+++ b/src/d/actor/d_a_nh.cpp
@@ -273,7 +273,7 @@ void daNh_c::BGCheck() {
     dBgS_ObjGndChk_All gndChk;
     gndChk.SetPos(&current.pos);
     f32 groundY = dComIfG_Bgsp()->GroundCross(&gndChk);
-    if (groundY != -1000000000.0f) {
+    if (groundY != C_BG_MIN_HEIGHT) {
         mGroundY = groundY;
         tevStr.mRoomNo = current.roomNo = dComIfG_Bgsp()->GetRoomId(gndChk);
         tevStr.mEnvrIdxOverride = dComIfG_Bgsp()->GetPolyColor(gndChk);
diff --git a/src/d/actor/d_a_npc_kamome.cpp b/src/d/actor/d_a_npc_kamome.cpp
index f70fbb3aa..7cea42425 100644
--- a/src/d/actor/d_a_npc_kamome.cpp
+++ b/src/d/actor/d_a_npc_kamome.cpp
@@ -1285,7 +1285,7 @@ BOOL daNpc_kam_c::execute() {
         
         if (!isNoBgCheck()) {
             mAcch.CrrPos(*dComIfG_Bgsp());
-            if (mAcch.GetGroundH() != -1000000000.0f) {
+            if (mAcch.GetGroundH() != C_BG_MIN_HEIGHT) {
                 s8 roomNo = dComIfG_Bgsp()->GetRoomId(mAcch.m_gnd);
                 fopAcM_SetRoomNo(this, roomNo);
                 tevStr.mRoomNo = roomNo;
diff --git a/src/d/actor/d_a_npc_os.cpp b/src/d/actor/d_a_npc_os.cpp
index b55c3fe49..6b52605d8 100644
--- a/src/d/actor/d_a_npc_os.cpp
+++ b/src/d/actor/d_a_npc_os.cpp
@@ -2129,7 +2129,7 @@ BOOL daNpc_Os_c::execute() {
             mAcch.CrrPos(*dComIfG_Bgsp());
             
             field_0x784 |= 0x10;
-            if(mAcch.GetGroundH() != -1.0e9f) {
+            if(mAcch.GetGroundH() != C_BG_MIN_HEIGHT) {
                 tevStr.mRoomNo = dComIfG_Bgsp()->GetRoomId(mAcch.m_gnd);
                 tevStr.mEnvrIdxOverride = dComIfG_Bgsp()->GetPolyColor(mAcch.m_gnd);
 
@@ -2206,7 +2206,7 @@ BOOL daNpc_Os_c::execute() {
             }
         }
 
-        if(mAcch.GetGroundH() != -1.0e9f) {
+        if(mAcch.GetGroundH() != C_BG_MIN_HEIGHT) {
             cM3dGPla* plane = dComIfG_Bgsp()->GetTriPla(mAcch.m_gnd.GetBgIndex(), mAcch.m_gnd.GetPolyIndex());
             if(plane) {
                 field_0x7F0 = *plane->GetNP();
@@ -2226,7 +2226,7 @@ BOOL daNpc_Os_c::execute() {
 
         field_0x7A8 = mAcch.ChkGroundHit();
         if(!fopAcM_checkCarryNow(this)) {
-            if(mAcch.GetGroundH() == -1.0e9f || dComIfG_Bgsp()->GetGroundCode(mAcch.m_gnd) == 4) {
+            if(mAcch.GetGroundH() == C_BG_MIN_HEIGHT || dComIfG_Bgsp()->GetGroundCode(mAcch.m_gnd) == 4) {
                 if(m4E8 < 30) {
                     m4E8 += 1;
                 }
@@ -2268,7 +2268,7 @@ BOOL daNpc_Os_c::execute() {
         mAcch.CrrPos(*dComIfG_Bgsp());
 
         field_0x784 |= 0x10;
-        if(mAcch.GetGroundH() != -1.0e9f) {
+        if(mAcch.GetGroundH() != C_BG_MIN_HEIGHT) {
             tevStr.mRoomNo = dComIfG_Bgsp()->GetRoomId(mAcch.m_gnd);
             tevStr.mEnvrIdxOverride = dComIfG_Bgsp()->GetPolyColor(mAcch.m_gnd);
         }
diff --git a/src/d/actor/d_a_npc_people.cpp b/src/d/actor/d_a_npc_people.cpp
index b650bdd40..d536f7804 100644
--- a/src/d/actor/d_a_npc_people.cpp
+++ b/src/d/actor/d_a_npc_people.cpp
@@ -4430,7 +4430,7 @@ s32 daNpcPeople_c::createInit() {
 
     if(mNpcType != 0xB) {
         mObjAcch.CrrPos(*dComIfG_Bgsp());
-        if(-1.0e9f != mObjAcch.GetGroundH()) {
+        if(C_BG_MIN_HEIGHT != mObjAcch.GetGroundH()) {
             current.pos.y = home.pos.y = mObjAcch.GetGroundH();
         }
     }
diff --git a/src/d/actor/d_a_npc_roten.cpp b/src/d/actor/d_a_npc_roten.cpp
index b89d5a1d0..1b2d04bf2 100644
--- a/src/d/actor/d_a_npc_roten.cpp
+++ b/src/d/actor/d_a_npc_roten.cpp
@@ -1733,7 +1733,7 @@ s32 daNpcRoten_c::createInit() {
     fopAcM_setCullSizeBox(this, -200.0f, 0.0f, -200.0f, 200.0f, 300.0f, 200.0f);
 
     mObjAcch.CrrPos(*dComIfG_Bgsp());
-    if(-1e9f != mObjAcch.GetGroundH()) {
+    if(C_BG_MIN_HEIGHT != mObjAcch.GetGroundH()) {
         current.pos.y = home.pos.y = mObjAcch.GetGroundH();
     }
 
diff --git a/src/d/actor/d_a_obj_movebox.cpp b/src/d/actor/d_a_obj_movebox.cpp
index 38e8acbd0..0da9612ff 100644
--- a/src/d/actor/d_a_obj_movebox.cpp
+++ b/src/d/actor/d_a_obj_movebox.cpp
@@ -116,7 +116,7 @@ namespace daObjMovebox {
     /* 000001F0-000003A4       .text gnd_pos__Q212daObjMovebox5Bgc_cFPCQ212daObjMovebox5Act_cPCQ212daObjMovebox8BgcSrc_cif */
     void Bgc_c::gnd_pos(const Act_c* movebox, const BgcSrc_c* bgcSrc, int bgcSrcCount, f32 param_4) {
         f32 tempz;
-        f32 maxGroundY = -1000000000.0f;
+        f32 maxGroundY = C_BG_MIN_HEIGHT;
         
         mDoMtx_stack_c::transS(movebox->current.pos);
         mDoMtx_stack_c::YrotM(movebox->home.angle.y);
@@ -1872,7 +1872,7 @@ namespace daObjMovebox {
             int temp = mBgc.mMaxGroundIdx;
             f32 groundH = mBgc.mGroundY[temp];
             cM3dGPla* triPla = dComIfG_Bgsp()->GetTriPla(Bgc_c::M_gnd_work[temp]);
-            if (triPla && groundH != -1000000000.0f) {
+            if (triPla && groundH != C_BG_MIN_HEIGHT) {
                 dComIfGd_setSimpleShadow(&current.pos, groundH, i_attr()->m10, triPla->GetNP(), shape_angle.y, 1.0f, NULL);
             }
         }
diff --git a/src/d/actor/d_a_player_main.cpp b/src/d/actor/d_a_player_main.cpp
index 630d892e2..da2891ba3 100644
--- a/src/d/actor/d_a_player_main.cpp
+++ b/src/d/actor/d_a_player_main.cpp
@@ -3087,7 +3087,7 @@ BOOL daPy_lk_c::checkLavaFace(cXyz* oldPos, int attributeCode) {
         mLavaGndChk.SetPos(&pos);
         m35D4 = dComIfG_Bgsp()->GroundCross(&mLavaGndChk);
         if (mAcch.GetGroundH() > m35D4) {
-            m35D4 = -1000000000.0f;
+            m35D4 = C_BG_MIN_HEIGHT;
         }
         if (m35D4 > current.pos.y) {
             attributeCode = dComIfG_Bgsp()->GetAttributeCode(mLavaGndChk);
@@ -3337,7 +3337,7 @@ BOOL daPy_lk_c::execute() {
         !dComIfGp_checkPlayerStatus0(0, daPyStts0_SHIP_RIDE_e) &&
         !checkModeFlg(ModeFlg_ROPE | ModeFlg_CLIMB | ModeFlg_LADDER) &&
         mCurProc != daPyProc_DEMO_TOOL_e &&
-        mAcch.GetGroundH() != -1e9f &&
+        mAcch.GetGroundH() != C_BG_MIN_HEIGHT &&
         !checkNoResetFlg0((daPy_FLG0)(daPyFlg0_UNK20000000 | daPyFlg0_UNK80000000)) &&
         dComIfG_Bgsp()->ChkPolySafe(mAcch.m_gnd) &&
         dComIfG_Bgsp()->ChkMoveBG(mAcch.m_gnd)
@@ -3495,7 +3495,7 @@ BOOL daPy_lk_c::execute() {
         }
     } else if (mCurProc == daPyProc_DEMO_TOOL_e) {
         current.pos = sp14;
-        if (m3574 != 0 && mAcch.GetGroundH() != -1e9f) {
+        if (m3574 != 0 && mAcch.GetGroundH() != C_BG_MIN_HEIGHT) {
             current.pos.y = mAcch.GetGroundH();
         }
     } else if (mCurProc == daPyProc_HOOKSHOT_FLY_e ||
@@ -3515,7 +3515,7 @@ BOOL daPy_lk_c::execute() {
     }
     
     int roomNo;
-    if (mAcch.GetGroundH() != -1e9f) {
+    if (mAcch.GetGroundH() != C_BG_MIN_HEIGHT) {
         roomNo = setRoomInfo();
         m357C = m3580;
         m3580 = dComIfG_Bgsp()->GetGroundCode(mAcch.m_gnd);
diff --git a/src/d/actor/d_a_player_npc.cpp b/src/d/actor/d_a_player_npc.cpp
index 0e38e3fa1..98278a1af 100644
--- a/src/d/actor/d_a_player_npc.cpp
+++ b/src/d/actor/d_a_player_npc.cpp
@@ -13,7 +13,7 @@
 int daPy_npc_c::check_initialRoom() {
     if (home.roomNo < 0) {
         mAcch.CrrPos(*dComIfG_Bgsp());
-        if (mAcch.GetGroundH() == -1000000000.0f || dComIfG_Bgsp()->GetGroundCode(mAcch.m_gnd) == 4) {
+        if (mAcch.GetGroundH() == C_BG_MIN_HEIGHT || dComIfG_Bgsp()->GetGroundCode(mAcch.m_gnd) == 4) {
             return 0;
         } else {
             int roomNo = dComIfG_Bgsp()->GetRoomId(mAcch.m_gnd);
diff --git a/src/d/actor/d_a_player_particle.inc b/src/d/actor/d_a_player_particle.inc
index 0ea595c4b..bdcd324d3 100644
--- a/src/d/actor/d_a_player_particle.inc
+++ b/src/d/actor/d_a_player_particle.inc
@@ -37,7 +37,7 @@ void daPy_swimTailEcallBack_c::getMaxWaterY(JGeometry::TVec3<f32>* pos) {
         if (field_0x10 > pos->y) {
             pos->y = field_0x10 + 2.0f;
         }
-    } else if (field_0x10 != -1e9f) {
+    } else if (field_0x10 != C_BG_MIN_HEIGHT) {
         pos->y = field_0x10 + 2.0f;
     } else {
         pos->y = field_0x0C;
@@ -899,7 +899,7 @@ void daPy_lk_c::setFootMark(cXyz* i_pos) {
     mGndChk.SetPos(&pos);
 
     pos.y = dComIfG_Bgsp()->GroundCross(&mGndChk);
-    if (pos.y != -1e9f && dComIfG_Bgsp()->GetAttributeCode(mGndChk) == dBgS_Attr_SAND_e) {
+    if (pos.y != C_BG_MIN_HEIGHT && dComIfG_Bgsp()->GetAttributeCode(mGndChk) == dBgS_Attr_SAND_e) {
         fopKyM_create(PROC_WATER_MARK, (shape_angle.y << 16) | 2, &pos, &scale, NULL);
     }
 
@@ -1049,7 +1049,7 @@ void daPy_lk_c::setFootEffect() {
             mGndChk.SetPos(&pos);
 
             f32 groundY = dComIfG_Bgsp()->GroundCross(&mGndChk);
-            if (groundY != -1e9f) {
+            if (groundY != C_BG_MIN_HEIGHT) {
                 pos.y = groundY;
             }
 
diff --git a/src/d/d_a_bomb_static.cpp b/src/d/d_a_bomb_static.cpp
index cff831245..1de8baf05 100644
--- a/src/d/d_a_bomb_static.cpp
+++ b/src/d/d_a_bomb_static.cpp
@@ -5,6 +5,7 @@
 
 #include "d/actor/d_a_bomb.h"
 #include "d/actor/d_a_bomb2.h"
+#include "d/d_a_obj.h"
 #include "JSystem/JUtility/JUTAssert.h"
 
 const int L_daBomb_Version = 1;
diff --git a/src/d/d_bg_s.cpp b/src/d/d_bg_s.cpp
index c560cc9e7..b396e9268 100644
--- a/src/d/d_bg_s.cpp
+++ b/src/d/d_bg_s.cpp
@@ -354,7 +354,7 @@ void dBgS::WallCorrect(dBgS_Acch* acch) {
 
 /* 800A13E0-800A14FC       .text RoofChk__4dBgSFP12dBgS_RoofChk */
 f32 dBgS::RoofChk(dBgS_RoofChk* chk) {
-    chk->SetNowY(1e+09f);
+    chk->SetNowY(C_BG_MAX_HEIGHT);
     chk->ClearPi();
     cBgS_ChkElm* elm;
     for (s32 bg_index = 0; bg_index < (s32)ARRAY_SIZE(m_chk_element); bg_index++) {
@@ -606,7 +606,7 @@ void dBgS_CrrPos::CrrPos(dBgS& i_bgs) {
         mGndChk.SetPos(&pos);
         f32 f31 = pm_pos->y;
         mGroundH = i_bgs.GroundCross(&mGndChk);
-        if (mGroundH != -1e+09f && mGroundH > f31) {
+        if (mGroundH != C_BG_MIN_HEIGHT && mGroundH > f31) {
             pm_pos->y = mGroundH;
             if (field_0x58) {
                 field_0x58->y = 0.0f;
diff --git a/src/d/d_bg_s_acch.cpp b/src/d/d_bg_s_acch.cpp
index 3c9bede6d..2380ac545 100644
--- a/src/d/d_bg_s_acch.cpp
+++ b/src/d/d_bg_s_acch.cpp
@@ -56,7 +56,7 @@ dBgS_Acch::dBgS_Acch() {
     pm_pos = NULL;
     pm_old_pos = NULL;
     pm_speed = NULL;
-    m_ground_h = -1000000000.0f;
+    m_ground_h = C_BG_MIN_HEIGHT;
     m_ground_up_h = 0.0f;
     m_ground_check_offset = 60.0f;
     m_ground_up_h_diff = 0.0f;
@@ -73,7 +73,7 @@ dBgS_Acch::dBgS_Acch() {
     pm_shape_angle = NULL;
     m_my_ac = NULL;
     pm_out_poly_info = NULL;
-    m_sea_height = -1000000000.0f;
+    m_sea_height = C_BG_MIN_HEIGHT;
 }
 
 static void dummy1() {
@@ -108,7 +108,7 @@ void dBgS_Acch::Set(cXyz* pos, cXyz* old_pos, fopAc_ac_c* actor, int tbl_size, d
 
 /* 800A2E80-800A2EE8       .text GroundCheckInit__9dBgS_AcchFR4dBgS */
 void dBgS_Acch::GroundCheckInit(dBgS&) {
-    m_ground_h = -1000000000.0f;
+    m_ground_h = C_BG_MIN_HEIGHT;
     if (m_flags & GRND_NONE) {
         return;
     }
@@ -131,7 +131,7 @@ void dBgS_Acch::GroundCheck(dBgS& i_bgs) {
     m_gnd.m_pos = pos;
 
     m_ground_h = i_bgs.GroundCross(&m_gnd);
-    if (m_ground_h != -1000000000.0f) {
+    if (m_ground_h != C_BG_MIN_HEIGHT) {
         field_0xb8 = m_ground_h + m_ground_up_h;
         if (field_0xb8 > field_0xb4) {
             pm_pos->y = field_0xb8;
@@ -155,8 +155,8 @@ void dBgS_Acch::GroundCheck(dBgS& i_bgs) {
 
 /* 800A305C-800A313C       .text GroundRoofProc__9dBgS_AcchFR4dBgS */
 f32 dBgS_Acch::GroundRoofProc(dBgS& i_bgs) {
-    f32 y = -1000000000.0f;
-    if (m_ground_h != -1000000000.0f) {
+    f32 y = C_BG_MIN_HEIGHT;
+    if (m_ground_h != C_BG_MIN_HEIGHT) {
         // y = m_roof_height;
         // fakematch to fix load order
         if (field_0xb8 < (y = m_roof_height) && y < pm_pos->y) {
@@ -257,14 +257,14 @@ void dBgS_Acch::CrrPos(dBgS& i_bgs) {
         LineCheck(i_bgs);
     }
 
-    m_roof_height = 1000000000.0f;
+    m_roof_height = C_BG_MAX_HEIGHT;
     if (!(m_flags & ROOF_NONE)) {
         m_roof.SetExtChk(*(cBgS_Chk*)this);
         ClrRoofHit();
         cXyz roofPos = *pm_pos;
         m_roof.SetPos(roofPos);
         m_roof_y = i_bgs.RoofChk(&m_roof);
-        if (m_roof_y != 1000000000.0f && pm_pos->y + m_roof_crr_height > m_roof_y) {
+        if (m_roof_y != C_BG_MAX_HEIGHT && pm_pos->y + m_roof_crr_height > m_roof_y) {
             m_roof_height = m_roof_y - m_roof_crr_height;
             SetRoofHit();
         }
@@ -281,10 +281,10 @@ void dBgS_Acch::CrrPos(dBgS& i_bgs) {
     if (!(m_flags & WATER_NONE)) {
         ClrWaterHit();
         ClrWaterIn();
-        m_wtr.SetHeight(-1000000000.0f);
+        m_wtr.SetHeight(C_BG_MIN_HEIGHT);
 
         int room_no = i_bgs.GetRoomId(m_gnd);
-        if (m_ground_h != -1000000000.0f && 0 <= room_no && room_no < 64) {
+        if (m_ground_h != C_BG_MIN_HEIGHT && 0 <= room_no && room_no < 64) {
             JUT_ASSERT(693, 0 <= room_no && room_no < 64);
 
             dBgW* bgw = dComIfGp_roomControl_getBgW(room_no);
@@ -312,7 +312,7 @@ void dBgS_Acch::CrrPos(dBgS& i_bgs) {
 
     if (ChkSeaCheckOn()) {
         m_flags &= ~SEA_IN;
-        m_sea_height = -1000000000.0f;
+        m_sea_height = C_BG_MIN_HEIGHT;
 
         if (daSea_ChkArea(pm_pos->x, pm_pos->z)) {
             m_sea_height = daSea_calcWave(pm_pos->x, pm_pos->z);
diff --git a/src/d/d_bg_s_func.cpp b/src/d/d_bg_s_func.cpp
index 75bc3687f..2bbafb2c8 100644
--- a/src/d/d_bg_s_func.cpp
+++ b/src/d/d_bg_s_func.cpp
@@ -34,7 +34,7 @@ bool dBgS_SplGrpChk_In_ObjGnd(cXyz& r30, dBgS_SplGrpChk* r31, f32 f31) {
     gndChk.SetPos(&sp1c);
     f32 height = dComIfG_Bgsp()->GroundCross(&gndChk);
     r31->SetHeight(height);
-    if (height == -1e9f) {
+    if (height == C_BG_MIN_HEIGHT) {
         return FALSE;
     }
     
@@ -79,7 +79,7 @@ u32 dBgS_GetGndMtrlSndId_Func(cXyz r21, f32 f1) {
     r21.y += f1;
     dBgS_ObjGndChk gndChk;
     gndChk.SetPos(&r21);
-    if (dComIfG_Bgsp()->GroundCross(&gndChk) == -1e9f) {
+    if (dComIfG_Bgsp()->GroundCross(&gndChk) == C_BG_MIN_HEIGHT) {
         return 0;
     }
     return dComIfG_Bgsp()->GetMtrlSndId(gndChk);
diff --git a/src/d/d_bg_s_spl_grp_chk.cpp b/src/d/d_bg_s_spl_grp_chk.cpp
index e1dcf4815..59e703795 100644
--- a/src/d/d_bg_s_spl_grp_chk.cpp
+++ b/src/d/d_bg_s_spl_grp_chk.cpp
@@ -4,7 +4,7 @@
 //
 
 #include "d/d_bg_s_spl_grp_chk.h"
-#include "dolphin/types.h"
+#include "SSystem/SComponent/c_bg_s.h"
 
 /* 800A5A7C-800A5B94       .text __ct__14dBgS_SplGrpChkFv */
 dBgS_SplGrpChk::dBgS_SplGrpChk() {
@@ -14,7 +14,7 @@ dBgS_SplGrpChk::dBgS_SplGrpChk() {
     m_ground.x = 0.0f;
     m_ground.y = 0.0f;
     m_ground.z = 0.0f;
-    m_roof = 1000000000.0f;
+    m_roof = C_BG_MAX_HEIGHT;
     m_height = 0.0f;
 }
 
@@ -25,4 +25,3 @@ void dBgS_SplGrpChk::Init() {
     SetHeight(GetPosP()->y);
     ClearPi();
 }
-
diff --git a/src/d/d_bg_w_hf.cpp b/src/d/d_bg_w_hf.cpp
index 5446c8ad0..6c1082b02 100644
--- a/src/d/d_bg_w_hf.cpp
+++ b/src/d/d_bg_w_hf.cpp
@@ -4,6 +4,7 @@
 //
 
 #include "d/d_bg_w_hf.h"
+#include "SSystem/SComponent/c_bg_s.h"
 #include "dolphin/types.h"
 
 #define CHECK_MINMAX_1(line, min, max)                                                             \
@@ -152,8 +153,8 @@ void dBgWHf::MakeBlckBndHf(int blck_id, f32* r28, f32* r29) {
         r31 = pm_bgd->m_t_num - 1;
     }
     
-    *r28 = 1000000000.0f;
-    *r29 = -1000000000.0f;
+    *r28 = C_BG_MAX_HEIGHT;
+    *r29 = C_BG_MIN_HEIGHT;
     
     for (int t = r7; t <= r31; t++) {
 #if VERSION != VERSION_JPN
diff --git a/src/d/d_cc_mass_s.cpp b/src/d/d_cc_mass_s.cpp
index c3f569cb2..c2e322079 100644
--- a/src/d/d_cc_mass_s.cpp
+++ b/src/d/d_cc_mass_s.cpp
@@ -6,6 +6,7 @@
 #include "d/d_cc_mass_s.h"
 #include "d/d_cc_d.h"
 #include "JSystem/JUtility/JUTAssert.h"
+#include "SSystem/SComponent/c_bg_s.h"
 #include "SSystem/SComponent/c_math.h"
 #include "f_op/f_op_actor.h"
 
@@ -19,10 +20,10 @@ void dCcMassS_Mng::Ct() {
     mFlag = 0;
     mResultCam = 0;
     mCamTopPos.x = 0.0f;
-    mCamTopPos.y = -1e+9f;
+    mCamTopPos.y = C_BG_MIN_HEIGHT;
     mCamTopPos.z = 0.0f;
     mCamBottomPos.x = 0.0f;
-    mCamBottomPos.y = -1e+9f;
+    mCamBottomPos.y = C_BG_MIN_HEIGHT;
     mCamBottomPos.z = 0.0f;
     Clear();
 }
@@ -70,13 +71,13 @@ void dCcMassS_Mng::Prepare() {
         mDivideArea.CalcDivideInfo(&mDivideInfo, mCpsAttr.GetWorkAab(), 0);
     }
     mCamTopPos.x = 0.0f;
-    mCamTopPos.y = -1e+9f;
+    mCamTopPos.y = C_BG_MIN_HEIGHT;
     mCamTopPos.z = 0.0f;
-    mCamTopDist = 1e+9f;
+    mCamTopDist = C_BG_MAX_HEIGHT;
     mCamBottomPos.x = 0.0f;
-    mCamBottomPos.y = -1e+9f;
+    mCamBottomPos.y = C_BG_MIN_HEIGHT;
     mCamBottomPos.z = 0.0f;
-    mCamBottomDist = 1e+9f;
+    mCamBottomDist = C_BG_MAX_HEIGHT;
 }
 
 /* 800ACCB8-800AD17C       .text Chk__12dCcMassS_MngFP4cXyzPP10fopAc_ac_cP15dCcMassS_HitInf */
diff --git a/src/d/d_com_inf_game.cpp b/src/d/d_com_inf_game.cpp
index 11d04f3da..4cdae031c 100644
--- a/src/d/d_com_inf_game.cpp
+++ b/src/d/d_com_inf_game.cpp
@@ -557,13 +557,13 @@ s8 dComIfGp_getReverb(int param_0) {
 
 /* 800534C4-800535B8       .text dComIfGd_setSimpleShadow2__FP4cXyzffR13cBgS_PolyInfosfP9_GXTexObj
  */
-int dComIfGd_setSimpleShadow2(cXyz* i_pos, f32 param_1, f32 param_2, cBgS_PolyInfo& i_floorPoly,
+int dComIfGd_setSimpleShadow2(cXyz* i_pos, f32 groundY, f32 param_2, cBgS_PolyInfo& i_floorPoly,
                               s16 i_angle, f32 param_5, GXTexObj* i_tex) {
-    if (i_floorPoly.ChkSetInfo() && -1000000000.0f != param_1) {
+    if (i_floorPoly.ChkSetInfo() && C_BG_MIN_HEIGHT != groundY) {
         cM3dGPla* plane_p =
             dComIfG_Bgsp()->GetTriPla(i_floorPoly);
 
-        return dComIfGd_setSimpleShadow(i_pos, param_1, param_2, plane_p->GetNP(), i_angle, param_5, i_tex);
+        return dComIfGd_setSimpleShadow(i_pos, groundY, param_2, plane_p->GetNP(), i_angle, param_5, i_tex);
     } else {
         return 0;
     }
@@ -1036,16 +1036,16 @@ u8 dComIfGs_checkGetItemNum(u8 i_itemNo) {
 
 /* 80054578-8005468C       .text dComIfGd_setShadow__FUlScP8J3DModelP4cXyzffffR13cBgS_PolyInfoP12dKy_tevstr_csfP9_GXTexObj */
 int dComIfGd_setShadow(u32 id, s8 param_2, J3DModel* pModel, cXyz* pPos, f32 param_5, f32 param_6,
-                       f32 y, f32 param_8, cBgS_PolyInfo& pFloorPoly, dKy_tevstr_c* param_10,
+                       f32 y, f32 groundY, cBgS_PolyInfo& pFloorPoly, dKy_tevstr_c* param_10,
                        s16 rotY, f32 param_12, GXTexObj* pTexObj) {
-    if (param_8 <= -1000000000.0f) {
+    if (groundY <= C_BG_MIN_HEIGHT) {
         return 0;
     }
 
-    int sid = dComIfGd_setRealShadow2(id, param_2, pModel, pPos, param_5, y - param_8, param_10);
+    int sid = dComIfGd_setRealShadow2(id, param_2, pModel, pPos, param_5, y - groundY, param_10);
     if (sid == 0) {
         cXyz pos(pPos->x, y, pPos->z);
-        dComIfGd_setSimpleShadow2(&pos, param_8, param_6, pFloorPoly, rotY, param_12, pTexObj);
+        dComIfGd_setSimpleShadow2(&pos, groundY, param_6, pFloorPoly, rotY, param_12, pTexObj);
     }
     return sid;
 }
diff --git a/src/d/d_drawlist.cpp b/src/d/d_drawlist.cpp
index f7d84729c..cdb86e67f 100644
--- a/src/d/d_drawlist.cpp
+++ b/src/d/d_drawlist.cpp
@@ -1827,11 +1827,11 @@ bool dDlst_shadowControl_c::addReal(u32 key, J3DModel* model) {
 }
 
 /* 80085274-800852D8       .text setSimple__21dDlst_shadowControl_cFP4cXyzffP4cXyzsfP9_GXTexObj */
-int dDlst_shadowControl_c::setSimple(cXyz* pos, f32 f0, f32 f1, cXyz* floor_nrm, s16 rotY, f32 f2, GXTexObj* tex) {
+int dDlst_shadowControl_c::setSimple(cXyz* pos, f32 groundY, f32 f1, cXyz* floor_nrm, s16 rotY, f32 f2, GXTexObj* tex) {
     if (floor_nrm == NULL || mSimpleNum >= ARRAY_SIZE(mSimple))
         return false;
 
-    mSimple[mSimpleNum].set(pos, f0, f1, floor_nrm, rotY, f2, tex);
+    mSimple[mSimpleNum].set(pos, groundY, f1, floor_nrm, rotY, f2, tex);
     mSimpleNum++;
     return true;
 }
diff --git a/src/d/d_grass.cpp b/src/d/d_grass.cpp
index d078aa582..d80c0eff4 100644
--- a/src/d/d_grass.cpp
+++ b/src/d/d_grass.cpp
@@ -352,7 +352,7 @@ static f32 checkGroundY(cXyz& pos) {
     chk.SetPos(&pos);
     f32 y = dComIfG_Bgsp()->GroundCross(&chk);
     pos.y -= 50.0f;
-    if (y <= -1000000000.0f)
+    if (y <= C_BG_MIN_HEIGHT)
         return pos.y;
     else
         return y;
diff --git a/src/d/d_kankyo_rain.cpp b/src/d/d_kankyo_rain.cpp
index 2d096780b..0b4130abc 100644
--- a/src/d/d_kankyo_rain.cpp
+++ b/src/d/d_kankyo_rain.cpp
@@ -726,7 +726,7 @@ bool overhead_bg_chk() {
     pos.y += 50.0f;
     roofChk.SetPos(pos);
 
-    if (dComIfG_Bgsp()->RoofChk(&roofChk) != 1000000000.0f)
+    if (dComIfG_Bgsp()->RoofChk(&roofChk) != C_BG_MAX_HEIGHT)
         ret = true;
     pos.y += 10000.0f;
     gndChk.SetPos(&pos);
@@ -755,7 +755,7 @@ bool forward_overhead_bg_chk(cXyz* pPos, f32 dist) {
     *pPos = pos;
     roofChk.SetPos(pos);
 
-    if (dComIfG_Bgsp()->RoofChk(&roofChk) != 1000000000.0f)
+    if (dComIfG_Bgsp()->RoofChk(&roofChk) != C_BG_MAX_HEIGHT)
         ret = true;
     pos.y += 10000.0f;
     gndChk.SetPos(&pos);
diff --git a/src/d/d_lib.cpp b/src/d/d_lib.cpp
index a83362d37..a3792ad8c 100644
--- a/src/d/d_lib.cpp
+++ b/src/d/d_lib.cpp
@@ -27,7 +27,7 @@ void dLib_setCirclePath(dLib_circle_path_c* path) {
 /* 800570CC-8005716C       .text dLib_getWaterY__FR4cXyzR12dBgS_ObjAcch */
 f32 dLib_getWaterY(cXyz& pos, dBgS_ObjAcch& acch) {
     BOOL waterHit = acch.ChkWaterHit();
-    f32 waterHeight = waterHit ? acch.m_wtr.GetHeight() : C_BG_INVALID_HEIGHT;
+    f32 waterHeight = waterHit ? acch.m_wtr.GetHeight() : C_BG_MIN_HEIGHT;
     if (daSea_ChkArea(pos.x, pos.z)) {
         f32 seaHeight = daSea_calcWave(pos.x, pos.z);
         if (!waterHit || seaHeight > waterHeight) {
diff --git a/src/d/d_particle.cpp b/src/d/d_particle.cpp
index 41acef786..5ec938051 100644
--- a/src/d/d_particle.cpp
+++ b/src/d/d_particle.cpp
@@ -773,7 +773,7 @@ JPABaseEmitter* dPa_control_c::setSimpleLand(int code, const cXyz* pos, const cs
         dBgS_ObjGndChk chk;
         cXyz chkPos(pos->x, pos->y + 10.0f, pos->z);
         chk.SetPos(&chkPos);
-        if (dComIfG_Bgsp()->GroundCross(&chk) != C_BG_INVALID_HEIGHT) {
+        if (dComIfG_Bgsp()->GroundCross(&chk) != C_BG_MIN_HEIGHT) {
             code = dComIfG_Bgsp()->GetAttributeCode(chk);
         }
     }
diff --git a/src/d/d_wood.cpp b/src/d/d_wood.cpp
index 185b16e54..f29da42fa 100644
--- a/src/d/d_wood.cpp
+++ b/src/d/d_wood.cpp
@@ -606,7 +606,7 @@ bool dWood::Unit_c::set_ground() {
     gndChk.SetPos(&pos);
     f32 gndHeight = dComIfG_Bgsp()->GroundCross(&gndChk);
 
-    if (gndHeight > -1000000000.0f) {
+    if (gndHeight > C_BG_MIN_HEIGHT) {
         mPos.y = gndHeight;
         cM3dGPla *triPla = dComIfG_Bgsp()->GetTriPla(gndChk);
 
diff --git a/src/d/d_wpot_water.cpp b/src/d/d_wpot_water.cpp
index 408963e7f..c023a5df1 100644
--- a/src/d/d_wpot_water.cpp
+++ b/src/d/d_wpot_water.cpp
@@ -76,8 +76,8 @@ s32 dWpotWater_c::create() {
 static s32 dWpotWater_Create(kankyo_class* i_k) {
     dWpotWater_c* i_this = (dWpotWater_c*)i_k;
     
-    dBgS_GndChk chk2;
-    dBgS_ObjGndChk_Yogan chk;
+    dBgS_GndChk gndChk;
+    dBgS_ObjGndChk_Yogan lavaChk;
     cXyz pos;
     
     s16 angle = 0;
@@ -88,13 +88,13 @@ static s32 dWpotWater_Create(kankyo_class* i_k) {
             i_this->mPos.y + 100.0f,
             i_this->mPos.z + f4 * cM_ssin(angle)
         );
-        chk.SetPos(&pos);
-        f32 ret = dComIfG_Bgsp()->GroundCross(&chk);
-        if (ret != -1000000000.0f) {
-            chk2.SetPos(&pos);
-            f32 ret2 = dComIfG_Bgsp()->GroundCross(&chk2);
-            if (chk.ChkSetInfo() && dComIfG_Bgsp()->GetAttributeCode(chk) == dBgS_Attr_LAVA_e && ret > ret2) {
-                cXyz spawnPos(pos.x, ret + 25.0f, pos.z);
+        lavaChk.SetPos(&pos);
+        f32 lavaY = dComIfG_Bgsp()->GroundCross(&lavaChk);
+        if (lavaY != C_BG_MIN_HEIGHT) {
+            gndChk.SetPos(&pos);
+            f32 groundY = dComIfG_Bgsp()->GroundCross(&gndChk);
+            if (lavaChk.ChkSetInfo() && dComIfG_Bgsp()->GetAttributeCode(lavaChk) == dBgS_Attr_LAVA_e && lavaY > groundY) {
+                cXyz spawnPos(pos.x, lavaY + 25.0f, pos.z);
                 fopAcM_create(PROC_Obj_Magmarock, 0, &spawnPos, i_this->mParam);
                 break;
             }
@@ -106,10 +106,10 @@ static s32 dWpotWater_Create(kankyo_class* i_k) {
         i_this->mPos.y + 100.0f,
         i_this->mPos.z
     );
-    chk2.SetPos(&pos);
-    f32 ret = dComIfG_Bgsp()->GroundCross(&chk2);
-    i_this->mPos.y = ret;
-    if (ret != -1000000000.0f) {
+    gndChk.SetPos(&pos);
+    f32 groundY = dComIfG_Bgsp()->GroundCross(&gndChk);
+    i_this->mPos.y = groundY;
+    if (groundY != C_BG_MIN_HEIGHT) {
         cXyz sp18(i_this->mPos.x, i_this->mPos.y, i_this->mPos.z);
         fopAcM_create(PROC_HITOBJ, 0, &sp18, i_this->mParam);
         return i_this->create();
diff --git a/src/f_op/f_op_actor_mng.cpp b/src/f_op/f_op_actor_mng.cpp
index 6555385f8..57c8097c9 100644
--- a/src/f_op/f_op_actor_mng.cpp
+++ b/src/f_op/f_op_actor_mng.cpp
@@ -1293,13 +1293,13 @@ BOOL fopAcM_getGroundAngle(fopAc_ac_c* actor, csXyz* p_angle) {
     pos.y = dComIfG_Bgsp()->GroundCross(&gndChk);
     s16 targetAngleX;
     int targetAngleZ;
-    if (pos.y != -1e9f) {
+    if (pos.y != C_BG_MIN_HEIGHT) {
         f32 origY = pos.y + 50.0f;
         gndChk.GetPointP()->set(pos.x, origY, pos.z + 10.0f);
         f32 origX = gndChk.GetPointP()->x;
         f32 origZ = gndChk.GetPointP()->z;
         f32 groundY = dComIfG_Bgsp()->GroundCross(&gndChk);
-        if (groundY != -1e9f) {
+        if (groundY != C_BG_MIN_HEIGHT) {
             targetAngleX = -cM_atan2s(groundY - pos.y, origZ - pos.z);
         } else {
             pos.y = pos.y; // ?? fakematch?
@@ -1311,7 +1311,7 @@ BOOL fopAcM_getGroundAngle(fopAc_ac_c* actor, csXyz* p_angle) {
         f32 tempZ = pos.z;
         gndChk.GetPointP()->set(origX, origY, tempZ);
         groundY = dComIfG_Bgsp()->GroundCross(&gndChk);
-        if (groundY != -1e9f) {
+        if (groundY != C_BG_MIN_HEIGHT) {
             targetAngleZ = cM_atan2s(groundY - pos.y, origX - pos.x);
         } else {
             ret = FALSE;
@@ -1412,7 +1412,7 @@ s32 fopAcM_getWaterY(const cXyz* pPos, f32* pDstWaterY) {
     static dBgS_WtrChk water_check;
     s32 ret = 0;
 
-    *pDstWaterY = -1e09;
+    *pDstWaterY = C_BG_MIN_HEIGHT;
 
     cXyz pos;
     pos.x = pPos->x;