MonoGame.Samples/FuelCell/FuelCell.Core/Game/FuelCell.cs

using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Audio;
using Microsoft.Xna.Framework.Content;
using Microsoft.Xna.Framework.Graphics;

namespace FuelCell
{
    public class FuelCell : GameObject
    {
        public bool Retrieved { get; set; }
        private SoundEffect fuelCellCollect;

        public FuelCell()
            : base()
        {
            Retrieved = false;
        }

        public void LoadContent(ContentManager content, string modelName)
        {
            Model = content.Load<Model>(modelName);
            BoundingSphere = CalculateBoundingSphere();
            Position = Vector3.Down;

            fuelCellCollect = content.Load<SoundEffect>("Audio/fuelcell-collect");

            BoundingSphere scaledSphere;
            scaledSphere = BoundingSphere;
            scaledSphere.Radius *= GameConstants.FuelCellBoundingSphereFactor;
            BoundingSphere = new BoundingSphere(scaledSphere.Center, scaledSphere.Radius);
        }

        public void Draw(Matrix view, Matrix projection)
        {
            Matrix translateMatrix = Matrix.CreateTranslation(Position);
            Matrix worldMatrix = translateMatrix;

            if (!Retrieved)
            {
                foreach (ModelMesh mesh in Model.Meshes)
                {
                    foreach (BasicEffect effect in mesh.Effects)
                    {
                        effect.World = worldMatrix;
                        effect.View = view;
                        effect.Projection = projection;

                        effect.EnableDefaultLighting();
                        effect.PreferPerPixelLighting = true;
                    }
                    mesh.Draw();
                }
            }
        }

        internal void Update(BoundingSphere vehicleBoundingSphere)
        {
            if (vehicleBoundingSphere.Intersects(this.BoundingSphere)
                && !this.Retrieved)
            {
                this.Retrieved = true;
                fuelCellCollect.Play();
            }
        }
    }
}