big

globals/acoustics.gd

@@ -35,6 +35,14 @@ const MATERIALS := {
 	"concrete": { "trans_db": -18.0, "trans_cutoff": 450.0,  "refl_db": -7.0,  "refl_cutoff": 3600.0 },
 	"metal":    { "trans_db": -11.0, "trans_cutoff": 1000.0, "refl_db": -4.0,  "refl_cutoff": 6000.0 },
 	"glass":    { "trans_db": -5.0,  "trans_cutoff": 2600.0, "refl_db": -9.0,  "refl_cutoff": 4200.0 },
+	# Loose aggregate — track ballast, a gravel path. Transmission is close to
+	# concrete's, because what a ray actually passes through is the bed under
+	# it, but REFLECTION is the opposite: a surface of loose stone scatters
+	# rather than reflects, so it returns little and returns it dull. Standing
+	# on the ballast should sound noticeably deader than standing on the road.
+	"gravel":   { "trans_db": -17.0, "trans_cutoff": 500.0,  "refl_db": -15.0, "refl_cutoff": 1800.0 },
+	# Turf and bare earth: the strongest absorbers in the set.
+	"grass":    { "trans_db": -19.0, "trans_cutoff": 400.0,  "refl_db": -18.0, "refl_cutoff": 1200.0 },
 }
 
 const OPEN_CUTOFF := 20500.0
@@ -55,7 +63,19 @@ static func classify(collider: Object) -> String:
 		return "concrete"
 	var node := collider as Node
 	if node.has_meta("acoustic_material"):
-		return node.get_meta("acoustic_material")
+		# Validated, not trusted. A level builder can set this meta to anything,
+		# and an unknown value used to reach `MATERIALS[mat]` directly and take
+		# the whole audio path down with it — a map tagged a slab "gravel"
+		# before gravel existed here, and every hitscan impact on it threw from
+		# inside occlusion(). A surface with an unrecognised material should
+		# sound like concrete, not stop the game making sound.
+		var tagged: String = str(node.get_meta("acoustic_material"))
+		if MATERIALS.has(tagged):
+			return tagged
+		push_warning("Acoustics: unknown acoustic_material '%s' on '%s'; using concrete."
+			% [tagged, node.name])
+		node.set_meta("acoustic_material", "concrete")   # cache, warn once
+		return "concrete"
 
 	var mat := "concrete"
 	var n := node.name.to_lower()