Disable collisions between attached bodies

bullet-featherstone/src/Base.hh

@@ -112,6 +112,13 @@ struct ModelInfo
   }
 };
 
+class GzMultiBodyLinkCollider: public btMultiBodyLinkCollider {
+  using btMultiBodyLinkCollider::btMultiBodyLinkCollider;
+
+	bool checkCollideWithOverride(const btCollisionObject* co) const override {
+    return btMultiBodyLinkCollider::checkCollideWithOverride(co) && btCollisionObject::checkCollideWithOverride(co);
+  }
+};
 /// Link information is embedded inside the model, so all we need to store here
 /// is a reference to the model and the index of this link inside of it.
 struct LinkInfo
@@ -120,7 +127,7 @@ struct LinkInfo
   std::optional<int> indexInModel;
   Identity model;
   Eigen::Isometry3d inertiaToLinkFrame;
-  std::unique_ptr<btMultiBodyLinkCollider> collider = nullptr;
+  std::unique_ptr<GzMultiBodyLinkCollider> collider = nullptr;
   std::unique_ptr<btCompoundShape> shape = nullptr;
   std::vector<std::size_t> collisionEntityIds = {};
   std::unordered_map<std::string, std::size_t> collisionNameToEntityId = {};

bullet-featherstone/src/SDFFeatures.cc

@@ -1263,7 +1263,7 @@ bool SDFFeatures::AddSdfCollision(
 
       // NOTE: Bullet does not appear to support different surface properties
       // for different shapes attached to the same link.
-      linkInfo->collider = std::make_unique<btMultiBodyLinkCollider>(
+      linkInfo->collider = std::make_unique<GzMultiBodyLinkCollider>(
         model->body.get(), linkIndexInModel);
 
       linkInfo->shape->addChildShape(btInertialToCollision, shape.get());