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// Stores a copy of the given model's vertex data.
// Jagged array indices are: [ModelMesh][ModelMeshPart][vertex]
VertexPositionNormalTexture[][][] vertices;
short[][][] indices;
 
// Index is [ModelMesh]
int[] boneIndices;
 
// Index is boneIndices[ModelMesh]
Matrix[] transforms;
 
public void GetModelData(Model model)
{
    if (model.Meshes[0].MeshParts[0].IndexBuffer.IndexElementSize != IndexElementSize.SixteenBits)
    {
        // Use int arrays instead of short for indices if this is a problem
        throw new Exception("Model uses 32-bit indices, which are not supported.");
    }
 
    vertices = new VertexPositionNormalTexture[model.Meshes.Count][][];
    indices = new short[model.Meshes.Count][][];
 
    transforms = new Matrix[model.Bones.Count];
    boneIndices = new int[model.Bones.Count];
 
    // Copy bone transforms so that meshes can be rendered in the correct positions
    model.CopyAbsoluteBoneTransformsTo(transforms);
 
    // Copy model data
    VertexPositionNormalTexture[] vertexBuffer =
    new VertexPositionNormalTexture[model.Meshes[0].MeshParts[0].VertexBuffer.VertexCount];
    short[] indexBuffer =
    new short[model.Meshes[0].MeshParts[0].IndexBuffer.IndexCount];
    model.Meshes[0].MeshParts[0].VertexBuffer.GetData<VertexPositionNormalTexture>(vertexBuffer);
    model.Meshes[0].MeshParts[0].IndexBuffer.GetData<short>(indexBuffer);
 
    // Convert vertex data into a usable format
    for (int i = 0; i < model.Meshes.Count; i++)
    {
        // Set up the indexing arrays
        boneIndices[i] = model.Meshes[i].ParentBone.Index;
 
        vertices[i] = new VertexPositionNormalTexture[model.Meshes[i].MeshParts.Count][];
        indices[i] = new short[model.Meshes[i].MeshParts.Count][];
 
        for (int j = 0; j < model.Meshes[i].MeshParts.Count; j++)
        {
            ModelMeshPart part = model.Meshes[i].MeshParts[j];
            vertices[i][j] = new VertexPositionNormalTexture[part.NumVertices];
            indices[i][j] = new short[part.PrimitiveCount * 3];
 
            // As far as I can tell, this only doesn't work due to it being broken in the API. If the intellisense
            // comments on these methods are correct then this should work.
            //part.VertexBuffer.GetData<VertexPositionNormalTexture>(vertices[i][j], part.VertexOffset, part.NumVertices);
            //part.IndexBuffer.GetData<short>(indices[i][j], part.StartIndex, part.PrimitiveCount * 3);
 
            Array.Copy(vertexBuffer, part.VertexOffset, vertices[i][j], 0, part.NumVertices);
            Array.Copy(indexBuffer, part.StartIndex, indices[i][j], 0, part.PrimitiveCount * 3);
        }
    }

    basicEffect.CurrentTechnique.Passes[0].Apply(); // replace with your effect
 
    for (int i = 0; i < indices.Length; i++)
    {
    // Set up the effect matrices
    //basicEffect.World = transforms[boneIndices[i]];
 
    for (int j = 0; j < indices[i].Length; j++)
    {
    graphicsDevice.DrawUserIndexedPrimitives<VertexPositionNormalTexture>(
        PrimitiveType.TriangleList,
        vertices[i][j],
        0,
        vertices[i][j].Length,
        indices[i][j],
        0,
        indices[i][j].Length / 3);
    }
 
}