diff --git a/src/shaders/antsCompute.frag b/src/shaders/antsCompute.frag
index df21707..4e8c9c4 100644
--- a/src/shaders/antsCompute.frag
+++ b/src/shaders/antsCompute.frag
@@ -32,21 +32,21 @@ vec2 roundUvToCellCenter(vec2 uv) {
 }
 
 bool tryGetFood(vec2 pos) {
-    float value = texture(tWorld, roundUvToCellCenter(pos)).x;
+    float materialId = texture(tWorld, roundUvToCellCenter(pos)).x;
 
-    return (int(value) & 1) == 1;
+    return int(materialId) == MAT_FOOD;
 }
 
 bool tryDropFood(vec2 pos) {
-    float value = texture(tWorld, roundUvToCellCenter(pos)).x;
+    float materialId = texture(tWorld, roundUvToCellCenter(pos)).x;
 
-    return ((int(value) & 2) >> 1) == 1;
+    return int(materialId) == MAT_HOME;
 }
 
 bool isObstacle(vec2 pos) {
-    float value = texture(tWorld, roundUvToCellCenter(pos)).x;
+    float materialId = texture(tWorld, roundUvToCellCenter(pos)).x;
 
-    return ((int(value) & 4) >> 2) == 1;
+    return int(materialId) == MAT_ROCK;
 }
 
 float smell(vec2 pos, float isCarrying) {