Matrix worldTransform = Matrix.Identity;            for (int i = 0; i < 500; ++i)            {                worldTransform.M41 = i * 2;                customModel.WorldTransform = worldTransform;                //modelDrawer.DrawInstancedModel(customModel);                                // OR               //modelDrawer.DrawModel(customModel);            }

        public void DrawModel(CustomModel customModel)        {            Effect effect = game.Effects[customModel.Effect];            GraphicsDevice graphicsDevice = game.GraphicsDevice;            Matrix[] transforms = customModel.ModelData.Transforms;            effect.Begin();            effect.CurrentTechnique.Passes[0].Begin();            for (int i = 0; i < customModel.Model.Meshes.Count; ++i)            {                ModelMesh mesh = customModel.Model.Meshes;                for (int ii = 0; ii < mesh.MeshParts.Count; ++ii)                {                    ModelMeshPart meshPart = mesh.MeshParts[ii];                    effect.Parameters["World"].SetValue(transforms[mesh.ParentBone.Index] * customModel.WorldTransform);                    effect.CommitChanges();                    graphicsDevice.VertexDeclaration = meshPart.VertexDeclaration;                    graphicsDevice.Vertices[0].SetSource(mesh.VertexBuffer, meshPart.StreamOffset, meshPart.VertexStride);                    graphicsDevice.Indices = mesh.IndexBuffer;                    graphicsDevice.DrawIndexedPrimitives(                        PrimitiveType.TriangleList,                        meshPart.BaseVertex,                        0,                        meshPart.NumVertices,                        meshPart.StartIndex,                        meshPart.PrimitiveCount                        );                }            }            effect.CurrentTechnique.Passes[0].End();            effect.End();        }

        public void DrawInstancedModel(CustomModel customModel)        {            if (!isInBeginEndPair)            {                throw new InvalidOperationException("Begin must be called successfully before a Draw can be called.");            }            int numModelIndices = customModel.ModelData.Indices.Length;            int numModelVertices = customModel.ModelData.Vertices.Length;            if (Reserve(numModelVertices, numModelIndices))            {                int count = 0;                int offset = 0;                Matrix[] transforms = customModel.ModelData.Transforms;                for (int i = 0; i < customModel.Model.Meshes.Count; ++i)                {                    ModelMesh mesh = customModel.Model.Meshes;                    for (int ii = 0; ii < mesh.MeshParts.Count; ++ii)                    {                        ModelMeshPart meshPart = mesh.MeshParts[ii];                        // Create and store the world transforms for each mesh part                        // The mesh part vertices' 'Index' property will be assigned the new transformIndex value                        offset += count;                        count = meshPart.NumVertices;                        for (int v = offset; v < offset + count; ++v)                        {                            customModel.ModelData.Vertices[v].Index = transformIndex;                        }                        // [World Transform]                        worldTransforms[transformIndex++] =                            transforms[mesh.ParentBone.Index] *                            customModel.WorldTransform;                    }                }                for (int i = 0; i < numModelIndices; ++i)                {                    indices[numIndices++] = (ushort)(numVertices + customModel.ModelData.Indices);                }                customModel.ModelData.Vertices.CopyTo(vertices, numVertices);                numVertices += numModelVertices;            }        }        private bool Reserve(int numV, int numI)        {            if (numV > MAXVERTICES || numI > MAXINDICES)            {                // Whatever it is, we can't draw it                return false;            }            if (numVertices + numV >= MAXVERTICES || numIndices + numI >= MAXINDICES || (transformIndex + 1) >= MAXMODELSPERBATCH)            {                // We can draw it, but we need to make room first                FlushDrawing();            }            return true;        }        private void FlushDrawing()        {            if (numIndices > 0)            {                Effect effect = game.Effects["ModelBatch"];                // Set parameters for current camera                game.SetSharedParameters(camera);                vertexBuffer.SetData(vertices, 0, numVertices, SetDataOptions.Discard);                indexBuffer.SetData(indices, 0, numIndices, SetDataOptions.Discard);                game.GraphicsDevice.Vertices[0].SetSource(vertexBuffer, 0, VertexPositionNormalTextureIndex.SizeInBytes);                game.GraphicsDevice.Indices = indexBuffer;                game.GraphicsDevice.VertexDeclaration = game.VertexDeclarations["VertexPositionNormalTextureIndex"];                // Set effect parameters                parameter_WorldTransforms.SetValue(worldTransforms);                // Make sure parameter effects take place before drawing                effect.CommitChanges();                effect.Begin();                effect.CurrentTechnique.Passes[0].Begin();                game.GraphicsDevice.DrawIndexedPrimitives(PrimitiveType.TriangleList, 0, 0, numVertices, 0, numIndices / 3);                effect.CurrentTechnique.Passes[0].End();                effect.End();            }            numIndices = 0;            numVertices = 0;            transformIndex = 0;        }

    class FPSCounter    {        private SpriteFont font;        private int frameRate = 0;        private Game1 game;        private int numFrames = 0;        private TimeSpan timeElapsed = TimeSpan.Zero;        public FPSCounter(Game1 game, SpriteFont font)        {            this.game = game;            this.font = font;        }        public void Draw()        {            string fps = string.Format("FPS: {0}", frameRate);            // Remove automatic anti aliasing            //sprite_Batch.GraphicsDevice.SamplerStates[0].MagFilter = TextureFilter.None;            //sprite_Batch.GraphicsDevice.SamplerStates[0].MinFilter = TextureFilter.None;            //sprite_Batch.GraphicsDevice.SamplerStates[0].MipFilter = TextureFilter.None;            game.SpriteBatch.DrawString(font, fps, new Vector2(0, 0), Color.Black);            game.SpriteBatch.DrawString(font, fps, new Vector2(1, 0), Color.White);        }        public void Update(GameTime gameTime)        {            timeElapsed += gameTime.ElapsedGameTime;            if (timeElapsed > TimeSpan.FromSeconds(1))            {                timeElapsed -= TimeSpan.FromSeconds(1);                frameRate = numFrames;                numFrames = 0;            }            numFrames++;        }    }

#define MAX_MODELS 50//=============================================//---[XNA to HLSL Variables]-------------------//=============================================shared float4x4 ViewProjection;shared float2 HalfPixel;texture Texture0;// Also keep in mind that if you're setting your matrices into shader constants in column-major format (which is the default), // then you don't need the last row since it will always be (0, 0, 0, 1). // So you can pack your matrices as float3x4's, and then each world matrix will only use 3 registers instead of 4.float4x4 WorldTransforms[MAX_MODELS];//=============================================//---[Texture Samplers]------------------------//=============================================sampler TextureSampler0 ={	sampler_state   	{   		Texture = <Texture0>;	       		MinFilter = None;   		MagFilter = None;   		MipFilter = None;   	       		AddressU = Clamp;  		AddressV = Clamp;	}};//=============================================//---[Structs]---------------------------------//=============================================struct VertexShaderInput{    float4 Position					: POSITION0;    float3 Normal					: NORMAL0;    float2 TextureCoordinates		: TEXCOORD0;    float Index						: PSIZE0;  };struct VertexShaderOutput{    float4 Position					: POSITION0;    float3 Normal					: NORMAL0;    float2 TextureCoordinates		: TEXCOORD0; };//=============================================//---[Vertex Shaders]--------------------------//=============================================VertexShaderOutput VertexShaderFunction(VertexShaderInput input){    VertexShaderOutput output = (VertexShaderOutput)0;		float4x4 worldTransform = WorldTransforms[round(input.Index)];			// [Transformation]	// • Multiplying input.Position by World then ViewProjection is faster than	//   concatenating World and ViewProjection matrices then multiplying input.Position by the result	input.Position = mul(input.Position, worldTransform);			output.Position = mul(input.Position, ViewProjection);		// Align texels to pixels (Half pixel offset for correct texel centering [DX9 Only])	// Should be done AFTER transformation	output.Position.xy -= HalfPixel;	output.TextureCoordinates = input.TextureCoordinates;    output.Normal = mul(input.Normal, worldTransform);                            return output;}//=============================================//---[Pixel Shaders]---------------------------//=============================================float4 PixelShaderFunction(VertexShaderOutput input) : COLOR0{	return tex2D(TextureSampler0, input.TextureCoordinates);}//=============================================//---[Techniques]------------------------------//=============================================technique Textured{    pass Pass0    {		    	AlphaBlendEnable = false;		// No transparency		ZEnable = true;		ZWriteEnable = true;						// Shadel Model 3.0 required for model instancing        VertexShader = compile vs_3_0 VertexShaderFunction();        PixelShader = compile ps_3_0 PixelShaderFunction();    }}technique Textured_Transparent{    pass Pass0    {				AlphaBlendEnable = true;		// Turn on Alpha Blending		ZEnable = true;		ZWriteEnable = true;			SrcBlend = One;					// Additive Blending		DestBlend = One;				// Additive Blending		BlendOp = Add;					// Additive Blending				// Shadel Model 3.0 required for model instancing        VertexShader = compile vs_3_0 VertexShaderFunction();        PixelShader = compile ps_3_0 PixelShaderFunction();				    }}