public void calculateNormal() {
        if (normal == null) {
            normal = new Vector3f(pointB);
        } else {
            normal.set(pointB);
        }
        normal.subtractLocal(pointA).crossLocal(pointC.x - pointA.x, pointC.y - pointA.y, pointC.z - pointA.z);
        normal.normalizeLocal();
    }
Recalculates the stored normal based on the current vertex locations.
jme3-core/src/main/java/com/jme3/math/Triangle.java