From a2399ea1f637a798a80aaa788a753d7936d73e1e Mon Sep 17 00:00:00 2001
From: Seth Alves <seth.alves@gmail.com>
Date: Fri, 8 Jun 2018 16:07:01 -0700
Subject: [PATCH] keep small masses from introducing NaN into bullet's
 calculations

---
 libraries/physics/src/PhysicsEngine.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/libraries/physics/src/PhysicsEngine.cpp b/libraries/physics/src/PhysicsEngine.cpp
index 83ffa21a55..1a258c0fc3 100644
--- a/libraries/physics/src/PhysicsEngine.cpp
+++ b/libraries/physics/src/PhysicsEngine.cpp
@@ -105,6 +105,10 @@ void PhysicsEngine::addObjectToDynamicsWorld(ObjectMotionState* motionState) {
         }
         case MOTION_TYPE_DYNAMIC: {
             mass = motionState->getMass();
+            if (mass != mass || mass < 1.0f) {
+                qCDebug(physics) << "mass is too low, setting to 1.0 Kg --" << mass;
+                mass = 1.0f;
+            }
             btCollisionShape* shape = const_cast<btCollisionShape*>(motionState->getShape());
             assert(shape);
             shape->calculateLocalInertia(mass, inertia);