diff --git a/source/build/src/engine.cpp b/source/build/src/engine.cpp
index 27c723701..9892651d8 100644
--- a/source/build/src/engine.cpp
+++ b/source/build/src/engine.cpp
@@ -7941,7 +7941,7 @@ int32_t drawrooms(int32_t daposx, int32_t daposy, int32_t daposz,
     case REND_POLYMOST:
         // NOTE: In Polymost, the fragment depth depends on the x screen size!
         if (r_usenewshading == 4)
-            globalvisibility = g_visibility;
+            globalvisibility = g_visibility * xdimen;
         else if (r_usenewshading >= 2)
             globalvisibility = scale(g_visibility<<2, xdimen, 1680);
         else
@@ -7949,7 +7949,10 @@ int32_t drawrooms(int32_t daposx, int32_t daposy, int32_t daposz,
         break;
 # ifdef POLYMER
     case REND_POLYMER:
-        globalvisibility = g_visibility<<2;
+        if (r_usenewshading == 4)
+            globalvisibility = g_visibility;
+        else
+            globalvisibility = g_visibility<<2;
         break;
 # endif
 #endif
diff --git a/source/build/src/polymer.cpp b/source/build/src/polymer.cpp
index 9f2643861..356208bcc 100644
--- a/source/build/src/polymer.cpp
+++ b/source/build/src/polymer.cpp
@@ -1083,7 +1083,7 @@ void                polymer_drawrooms(int32_t daposx, int32_t daposy, int32_t da
 
     if (pr_verbosity >= 3) OSD_Printf("PR : Drawing rooms...\n");
 
-    // fogcalc needs this
+    // fogcalc_old needs this
     gvisibility = ((float)globalvisibility)*FOGSCALE;
 
     ang = (float)(daang) * (360.f/2048.f);
@@ -5265,7 +5265,9 @@ static int32_t      polymer_bindmaterial(const _prmaterial *material, int16_t* l
         texunit++;
 
         bglUniform1fARB(prprograms[programbits].uniform_shadeOffset, (GLfloat)material->shadeoffset);
-        bglUniform1fARB(prprograms[programbits].uniform_visibility, globalvisibility/2048.0 * material->visibility);
+        // the furthest visible point is the same as Polymost, however the fog in Polymer is a sphere insted of a plane
+        float const visfactor = r_usenewshading == 4 ? 1.f/512.f : 1.f/2048.f;
+        bglUniform1fARB(prprograms[programbits].uniform_visibility, globalvisibility * visfactor * material->visibility);
     }
 
     // PR_BIT_DIFFUSE_MAP
diff --git a/source/build/src/polymost.cpp b/source/build/src/polymost.cpp
index c3a4853fe..f0ac48d16 100644
--- a/source/build/src/polymost.cpp
+++ b/source/build/src/polymost.cpp
@@ -496,7 +496,7 @@ void calc_and_apply_fog(int32_t tile, int32_t shade, int32_t vis, int32_t pal)
 
         if (((uint8_t)(vis + 16)) > 0 && g_visibility > 0)
         {
-            GLfloat glfogconstant = 262144.f / xdimen;
+            GLfloat glfogconstant = 262144.f;
             GLfloat fogrange = (frealmaxshade * glfogconstant) / (((uint8_t)(vis + 16)) * globalvisibility);
             GLfloat normalizedshade = shade / frealmaxshade;
             GLfloat fogshade = normalizedshade * fogrange;