Physics with Bullet - jMonkeyEngine 3.0 - page 411

How to do it...
In this recipe, we'll create three classes. Let's begin by looking at the Arrow class, which
contains most of the new functionalities. This will be done in the following eight steps:
1. We create a new class called Arrow , extending Node .
2. Its constructor takes two Vector3f variables as parameters. One of these is for
the starting location of the arrow and one for the initial velocity, as shown in the
following line of code:
public Arrow(Vector3f location, Vector3f velocity)
3. Inside the constructor, we define a Geometry instance for the body of the arrow
with a box mesh as follows:
Box arrowBody = new Box(0.3f, 4f, 0.3f);
Geometry geometry = new Geometry("bullet", arrowBody);
4. Then, we set localTranslation of Geometry so that one of its ends touches
the center point of the node as follows:
geometry.setLocalTranslation(0f, -4f, 0f);
5. We set localTranslation of this Arrow as the supplied location.
6. Next, we create CollisionShape . This will represent the head of the arrow and
can be SphereCollisionShape , as follows:
SphereCollisionShape arrowHeadCollision = new
SphereCollisionShape(0.5f);
7. Now, we define RigidBodyControl based on CollisionShape , as fol-
lows:
RigidBodyControl rigidBody = new
RigidBodyControl(arrowHeadCollision, 1f);
8. We set LinearVelocity of RigidBodyControl to be the supplied velocity
and add it as a Control to Arrow, as follows:
rigidBody.setLinearVelocity(velocity);
addControl(rigidBody);