diff --git a/src/game/bg.c b/src/game/bg.c
index 0b2c0b03b..3eaf35fc9 100644
--- a/src/game/bg.c
+++ b/src/game/bg.c
@@ -984,7 +984,9 @@ Gfx *bgRenderScene(Gfx *gdl)
 	s16 roomorder[60];
 	RoomNum roomnums[60];
 
+#ifdef PLATFORM_N64
 	g_NumRoomsWithGlares = 0;
+#endif
 
 	if (g_Vars.currentplayer->visionmode == VISIONMODE_XRAY) {
 		gdl = bgRenderSceneInXray(gdl);
@@ -1206,6 +1208,7 @@ Gfx *bgRenderScene(Gfx *gdl)
 			gdl = propsRender(gdl, thing->roomnum, RENDERPASS_XLU, roomnumsbyprop);
 		}
 
+#ifdef PLATFORM_N64 // on PC we do this earlier, before prop matrices turn into garbage
 		if (!g_Vars.mplayerisrunning) {
 			artifactsCalculateGlaresForRoom(thing->roomnum);
 
@@ -1213,6 +1216,7 @@ Gfx *bgRenderScene(Gfx *gdl)
 				g_GlareRooms[g_NumRoomsWithGlares++] = thing->roomnum;
 			}
 		}
+#endif
 	}
 
 #if VERSION < VERSION_NTSC_1_0
@@ -6397,3 +6401,21 @@ void bgFindEnteredRooms(struct coord *bbmin, struct coord *bbmax, RoomNum *rooms
 end:
 	rooms[len] = -1;
 }
+
+#ifndef PLATFORM_N64
+
+void bgCalculateGlaresForVisibleRooms(void)
+{
+	s32 i;
+	g_NumRoomsWithGlares = 0;
+	for (i = 1; i < g_Vars.roomcount; i++) {
+		if (g_Rooms[i].flags & ROOMFLAG_ONSCREEN) {
+			artifactsCalculateGlaresForRoom(i);
+			if (g_NumRoomsWithGlares < 100) {
+				g_GlareRooms[g_NumRoomsWithGlares++] = i;
+			}
+		}
+	}
+}
+
+#endif
diff --git a/src/game/game_13c510.c b/src/game/game_13c510.c
index 6258fff51..8ac5f0515 100644
--- a/src/game/game_13c510.c
+++ b/src/game/game_13c510.c
@@ -20,7 +20,7 @@
 #include "lib/collision.h"
 #include "lib/lib_17ce0.h"
 #include "game/player.h"
-f32 fabsf(f32 value);
+#include "game/prop.h"
 #endif
 
 u8 *var800a41a0;
@@ -104,8 +104,10 @@ s32 func0f13c710(f32 arg0)
 
 #ifndef PLATFORM_N64
 
-bool artifactTestLos(struct coord *spec, struct coord *roompos)
+bool artifactTestLos(struct coord *spec, struct coord *roompos, s32 xi, s32 yi)
 {
+	s32 i = 0;
+
 	if (!g_Vars.currentplayer) {
 		return false;
 	}
@@ -115,35 +117,15 @@ bool artifactTestLos(struct coord *spec, struct coord *roompos)
 	endpos.y = roompos->y + spec->y;
 	endpos.z = roompos->z + spec->z;
 
-	// get what rooms the LOS goes through
-	RoomNum outrooms[17], tmprooms[8], srcrooms[2];
-	srcrooms[0] = g_Vars.currentplayer->cam_room;
-	srcrooms[1] = -1;
-	outrooms[16] = -1;
-	portal00018148(&g_Vars.currentplayer->cam_pos, &endpos, srcrooms, tmprooms, outrooms, 16);
-
-	// cheaper LOS test against props first
-	const u32 cdtype = CDTYPE_OBJS | CDTYPE_DOORS | CDTYPE_PLAYERS | CDTYPE_CHRS;
-	const u16 geoflags = GEOFLAG_BLOCK_SIGHT | GEOFLAG_BLOCK_SHOOT;
-	if (!cdTestAToB(&g_Vars.currentplayer->cam_pos, &endpos, outrooms, cdtype, geoflags, true, 1, 0, 0)) {
-		return false;
-	}
-
-	// no prop was hit; check for bg hits
-	struct hitthing hit;
-	for (s32 i = 0; outrooms[i] != -1; ++i) {
-		if (bgTestHitInRoom(&g_Vars.currentplayer->cam_pos, &endpos, outrooms[i], &hit)) {
-			// check if it's far enough away from the end point
-			if (fabsf(hit.pos.x - endpos.x) >= 0.1f ||
-					fabsf(hit.pos.y - endpos.y) >= 0.1f ||
-					fabsf(hit.pos.z - endpos.z) >= 0.1f) {
-				return false;
-			}
-		}
-	}
+	struct coord gundir2d;
+	struct coord gunpos2d = {{ 0.f, 0.f, 0.f }};
+	struct coord gundir3d;
+	struct coord gunpos3d = g_Vars.currentplayer->cam_pos;
+	f32 crosspos[2] = { (f32)xi, (f32)yi };
+	cam0f0b4c3c(crosspos, &gundir2d, 1.f);
+	mtx4RotateVec(camGetProjectionMtxF(), &gundir2d, &gundir3d);
 
-	// nothing hit
-	return true;
+	return shotTestLos(&gunpos2d, &gundir2d, &gunpos3d, &gundir3d, &endpos);
 }
 
 #endif
@@ -380,7 +362,7 @@ void artifactsCalculateGlaresForRoom(s32 roomnum)
 
 								if (index < MAX_ARTIFACTS) {
 #ifndef PLATFORM_N64
-									artifact->unk02 = artifactTestLos(&spec, &g_BgRooms[roomnum].pos);
+									artifact->unk02 = artifactTestLos(&spec, &g_BgRooms[roomnum].pos, xi, yi);
 #endif
 									artifact->unk04 = func0f13c574(f0) >> 2;
 									artifact->unk08 = &g_ZbufPtr1[viGetWidth() * yi + xi];
diff --git a/src/game/lv.c b/src/game/lv.c
index 1c746b77d..c19cfbede 100644
--- a/src/game/lv.c
+++ b/src/game/lv.c
@@ -1194,6 +1194,11 @@ Gfx *lvRender(Gfx *gdl)
 				autoaimTick();
 				handsTickAttack();
 
+#ifndef PLATFORM_N64
+				// glares calculated earlier on PC, before prop matrices turn into garbage
+				bgCalculateGlaresForVisibleRooms();
+#endif
+
 				// Calculate lookingatprop
 				if (PLAYERCOUNT() == 1
 						|| g_Vars.coopplayernum >= 0
diff --git a/src/game/prop.c b/src/game/prop.c
index 92505fa3a..4dbbba9f0 100644
--- a/src/game/prop.c
+++ b/src/game/prop.c
@@ -973,6 +973,117 @@ struct prop *shotCalculateHits(s32 handnum, bool isshooting, struct coord *gunpo
 	return result;
 }
 
+#ifndef PLATFORM_N64
+
+/**
+ * Checks if the specified line of sight (gunpos3d - endpos3d) intersects any props or BG,
+ * using the same process as shotCalculateHits, except with no side effects and cheap = true.
+ * Returns true if nothing was hit.
+ */
+bool shotTestLos(struct coord *gunpos2d, struct coord *gundir2d, struct coord *gunpos3d, struct coord *gundir3d, struct coord *endpos3d)
+{
+	struct prop **propptr;
+	struct hitthing sp664;
+	struct coord delta;
+	struct shotdata shotdata;
+	s32 i;
+	RoomNum rooms[131];
+	RoomNum spc8[8];
+	RoomNum spb8[8];
+	RoomNum *roomsptr;
+	struct prop *prop;
+
+	shotdata.gunpos3d.x = gunpos3d->x;
+	shotdata.gunpos3d.y = gunpos3d->y;
+	shotdata.gunpos3d.z = gunpos3d->z;
+
+	shotdata.gunpos2d.x = gunpos2d->x;
+	shotdata.gunpos2d.y = gunpos2d->y;
+	shotdata.gunpos2d.z = gunpos2d->z;
+
+	shotdata.gundir3d.x = gundir3d->x;
+	shotdata.gundir3d.y = gundir3d->y;
+	shotdata.gundir3d.z = gundir3d->z;
+
+	shotdata.gundir2d.x = gundir2d->x;
+	shotdata.gundir2d.y = gundir2d->y;
+	shotdata.gundir2d.z = gundir2d->z;
+
+	// use falcon2 as a dummy weapon
+	shotdata.gset.weaponnum = WEAPON_FALCON2;
+	shotdata.gset.weaponfunc = 0;
+	shotdata.gset.unk063a = 0;
+	shotdata.gset.unk0639 = 0;
+
+	shotdata.penetration = 1;
+	shotdata.distance = 999999999.f;
+
+	for (i = 0; i < ARRAYCOUNT(shotdata.hits); i++) {
+		shotdata.hits[i].prop = NULL;
+		shotdata.hits[i].hitpart = 0;
+		shotdata.hits[i].bboxnode = NULL;
+	}
+
+	rooms[0] = rooms[130] = -1;
+	spc8[0] = g_Vars.currentplayer->cam_room;
+	spc8[1] = -1;
+	portal00018148(&shotdata.gunpos3d, endpos3d, spc8, spb8, rooms, 30);
+
+	roomsptr = rooms;
+
+	while (*roomsptr != -1) {
+		roomsptr++;
+	}
+
+	// Note this is being appended to rooms
+	bgGetForceOnscreenRooms(roomsptr, 100);
+
+	// Check for BG hits first
+	for (i = 0; rooms[i] != -1; i++) {
+		if (bgTestHitInRoom(&shotdata.gunpos3d, endpos3d, rooms[i], &sp664)) {
+			// check if it's far enough away from the end point
+			if (fabsf(sp664.pos.x - endpos3d->x) >= 0.1f ||
+					fabsf(sp664.pos.y - endpos3d->y) >= 0.1f ||
+					fabsf(sp664.pos.z - endpos3d->z) >= 0.1f) {
+				return false;
+			}
+		}
+	}
+
+	// didn't hit any bg, shrink distance to the line size
+	delta.x = endpos3d->x - gunpos3d->x;
+	delta.y = endpos3d->y - gunpos3d->y;
+	delta.z = endpos3d->z - gunpos3d->z;
+	shotdata.distance = sqrtf(delta.x * delta.x + delta.y * delta.y + delta.z * delta.z);
+
+	// and check props
+	propptr = g_Vars.endonscreenprops - 1;
+	while (propptr >= g_Vars.onscreenprops) {
+		prop = *propptr;
+		if (prop) {
+			if (prop->type == PROPTYPE_CHR
+					|| (prop->type == PROPTYPE_PLAYER && prop->chr && playermgrGetPlayerNumByProp(prop) != g_Vars.currentplayernum)) {
+				chrTestHit(prop, &shotdata, false, true);
+			} else if (prop->type == PROPTYPE_WEAPON || prop->type == PROPTYPE_DOOR
+					|| (prop->type == PROPTYPE_OBJ && prop->obj->type != OBJTYPE_GLASS && prop->obj->type != OBJTYPE_TINTEDGLASS)) {
+				objTestHit(prop, &shotdata);
+			}
+			if (shotdata.hits[0].prop) {
+				// ignore some glass parts and shields
+				if (shotdata.hits[0].slowsbullet && shotdata.hits[0].hitthing.texturenum != 10000) {
+					return false;
+				}
+			}
+		}
+		propptr--;
+	}
+
+	// did not hit anything
+	return true;
+}
+
+#endif
+
 struct prop *propFindAimingAt(s32 handnum, bool isshooting, u32 context)
 {
 	struct coord gundir2d;
diff --git a/src/game/sky.c b/src/game/sky.c
index e46110911..e610cad83 100644
--- a/src/game/sky.c
+++ b/src/game/sky.c
@@ -2518,7 +2518,7 @@ void skyCreateSunArtifact(struct artifact *artifact, s32 x, s32 y)
 		sunpos.x = env->suns[i].pos[0];
 		sunpos.y = env->suns[i].pos[1];
 		sunpos.z = env->suns[i].pos[2];
-		artifact->unk02 = artifactTestLos(&sunpos, &zero) * 0xfffc;
+		artifact->unk02 = artifactTestLos(&sunpos, &zero, x, y) * 0xfffc;
 #endif
 		artifact->unk08 = &g_ZbufPtr1[(s32)camGetScreenWidth() * y + x];
 		artifact->unk0c.u16_2 = x;
diff --git a/src/include/game/bg.h b/src/include/game/bg.h
index 0ac8645ca..89b6c7550 100644
--- a/src/include/game/bg.h
+++ b/src/include/game/bg.h
@@ -102,5 +102,8 @@ s32 bgFindPortalBetweenPositions(struct coord *pos1, struct coord *pos2);
 bool bgIsBboxOverlapping(struct coord *arg0, struct coord *arg1, struct coord *arg2, struct coord *arg3);
 void bgCalculatePortalBbox(s32 portalnum, struct coord *bbmin, struct coord *bbmax);
 void bgFindEnteredRooms(struct coord *bbmin, struct coord *upper, RoomNum *rooms, s32 maxlen, bool arg4);
+#ifndef PLATFORM_N64
+void bgCalculateGlaresForVisibleRooms(void);
+#endif
 
 #endif
diff --git a/src/include/game/game_13c510.h b/src/include/game/game_13c510.h
index 187cbc6ce..d8ee2f6dd 100644
--- a/src/include/game/game_13c510.h
+++ b/src/include/game/game_13c510.h
@@ -14,7 +14,7 @@ Gfx *artifactsConfigureForGlares(Gfx *gdl);
 Gfx *artifactsUnconfigureForGlares(Gfx *gdl);
 Gfx *artifactsRenderGlaresForRoom(Gfx *gdl, s32 roomnum);
 #ifndef PLATFORM_N64
-bool artifactTestLos(struct coord *spec, struct coord *roompos);
+bool artifactTestLos(struct coord *spec, struct coord *roompos, s32 xi, s32 yi);
 #endif
 
 #endif
diff --git a/src/include/game/prop.h b/src/include/game/prop.h
index 2105cc061..cdbab1737 100644
--- a/src/include/game/prop.h
+++ b/src/include/game/prop.h
@@ -65,4 +65,8 @@ void propsDefragRoomProps(void);
 void propGetBbox(struct prop *prop, f32 *radius, f32 *ymax, f32 *ymin);
 bool propUpdateGeometry(struct prop *prop, u8 **start, u8 **end);
 
+#ifndef PLATFORM_N64
+bool shotTestLos(struct coord *gunpos2d, struct coord *gundir2d, struct coord *gunpos3d, struct coord *gundir3d, struct coord *endpos3d);
+#endif
+
 #endif