Sponsor characters no longer potentially NaN out by reaching the targ…

…et goal (or otherwise having an influence sum of zero).
bepu · Apr 6, 2023 · 22dac46 · 22dac46
1 parent 240455a
commit 22dac46
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Showing 3 changed files with 7 additions and 5 deletions.
diff --git a/Demos/Demos/Sponsors/SponsorCharacterAI.cs b/Demos/Demos/Sponsors/SponsorCharacterAI.cs
@@ -29,7 +29,7 @@ public SponsorCharacterAI(CharacterControllers characters, in CollidableDescript
             this.targetLocation = targetLocation;
         }
 
-        public void Update(CharacterControllers characters, Simulation simulation, ref QuickList<SponsorNewt> newts, in Vector2 arenaMin, in Vector2 arenaMax, Random random)
+        public void Update(CharacterControllers characters, Simulation simulation, ref QuickList<SponsorNewt> newts, Random random)
         {
             var body = simulation.Bodies[bodyHandle];
             Vector2 influenceSum = default;
@@ -44,7 +44,7 @@ public void Update(CharacterControllers characters, Simulation simulation, ref Q
                     var influenceMagnitude = 1f / (distance * 0.1f + .1f);
                     influenceSum -= new Vector2(offset.X, offset.Z) * influenceMagnitude / distance;
                 }
-                if(distance < 20)
+                if (distance < 20)
                 {
                     spooked = true;
                 }
@@ -53,7 +53,9 @@ public void Update(CharacterControllers characters, Simulation simulation, ref Q
             influenceSum /= newts.Count;
             ref var character = ref characters.GetCharacterByBodyHandle(bodyHandle);
             influenceSum -= (new Vector2(body.Pose.Position.X, body.Pose.Position.Z) - targetLocation) * 0.001f;
-            var targetWorldVelocity = 6f * Vector2.Normalize(influenceSum);
+            //Newts should do a good job at avoiding a division by zero here, but just in case, guard against it.
+            var influenceSumLength = influenceSum.Length();
+            var targetWorldVelocity = influenceSumLength > 1e-6f ? influenceSum * (6f / influenceSumLength) : new Vector2();
             //Rephrase the target velocity in terms of the character's control basis. 
             character.TargetVelocity = new Vector2(targetWorldVelocity.X, -targetWorldVelocity.Y);
             if (spooked && random.NextDouble() < 0.015f)

diff --git a/Demos/Demos/Sponsors/SponsorDemo.cs b/Demos/Demos/Sponsors/SponsorDemo.cs
@@ -239,7 +239,7 @@ public override void Update(Window window, Camera camera, Input input, float dt)
             }
             for (int i = 0; i < characterAIs.Count; ++i)
             {
-                characterAIs[i].Update(characterControllers, Simulation, ref newts, newtArenaMin, newtArenaMax, random);
+                characterAIs[i].Update(characterControllers, Simulation, ref newts, random);
             }
             simulationTime += TimestepDuration;
             realTime += dt;

diff --git a/Demos/SpecializedTests/Media/2.4/NewtTyrannyDemo.cs b/Demos/SpecializedTests/Media/2.4/NewtTyrannyDemo.cs
@@ -101,7 +101,7 @@ public override void Update(Window window, Camera camera, Input input, float dt)
             }
             for (int i = 0; i < characterAIs.Count; ++i)
             {
-                characterAIs[i].Update(characterControllers, Simulation, ref newts, newtArenaMin, newtArenaMax, random);
+                characterAIs[i].Update(characterControllers, Simulation, ref newts, random);
             }
             simulationTime += TimestepDuration;