adjust artifact probability equation (#13229)

Content.Server/Xenoarchaeology/XenoArtifacts/ArtifactSystem.Nodes.cs

@@ -18,6 +18,7 @@ public sealed partial class ArtifactSystem
     /// <summary>
     /// Generate an Artifact tree with fully developed nodes.
     /// </summary>
+    /// <param name="artifact"></param>
     /// <param name="tree">The tree being generated.</param>
     /// <param name="nodeAmount">The amount of nodes it has.</param>
     private void GenerateArtifactNodeTree(EntityUid artifact, ref ArtifactTree tree, int nodeAmount)
@@ -114,12 +115,12 @@ public sealed partial class ArtifactSystem
     /// </remarks>
     private Dictionary<int, float> GetDepthWeights(IEnumerable<int> depths, int targetDepth)
     {
+        // this function is just a normal distribution with a
+        // mean of target depth and standard deviation of 0.75
         var weights = new Dictionary<int, float>();
         foreach (var d in depths)
         {
-            //TODO: is this equation sus? idk. -emo
-            // 0.3 / (|current_iterated_depth - our_actual_depth| + 1)^2
-            var w = 0.3f / MathF.Pow(Math.Abs(d - targetDepth) + 1, 2);
+            var w = 10f / (0.75f * MathF.Sqrt(2 * MathF.PI)) * MathF.Pow(MathF.E, -MathF.Pow((d - targetDepth) / 0.75f, 2));
             weights.Add(d, w);
         }
         return weights;