DrawUserPrimitives problems on Monogame

Question

I'm trying to draw a simple coloured rectangle on Monogame (for Windows8) using the 3D primitives DrawUserPrimitives and VertexPositionColor, but the only thing I can see is a rectangle that covers the upper half of the screen, as you can see in the screenshot below. This occurs when drawing a triangle, too.

Here's my code:

// camera code
Camera.Position = new Vector3(0, 1500, 0);
Camera.Projection = Matrix.CreatePerspectiveFieldOfView(MathHelper.ToRadians(45), GraphicsDevice.Viewport.AspectRatio, 1, 5000);
Camera.View = Matrix.CreateLookAt(Camera.Position, Vector3.Down, Vector3.Forward); 

VertexPositionColor[] vertexList = new VertexPositionColor[4]; 
BasicEffect basicEffect;  
VertexBuffer vertexBuffer;

// initializations
vertexList[0] = new VertexPositionColor(new Vector3(-957, 10, -635), Color.Red);  
vertexList[1] = new VertexPositionColor(new Vector3(957, 10, -635), Color.Lime);  
vertexList[2] = new VertexPositionColor(new Vector3(-957, 10, 635), Color.Yellow);  
vertexList[3] = new VertexPositionColor(new Vector3(957, 10, 635), Color.Blue);

vertexBuffer = new VertexBuffer(GraphicsDevice, typeof(VertexPositionColor), 4, BufferUsage.WriteOnly);  
vertexBuffer.SetData<VertexPositionColor>(vertexList);

basicEffect = new BasicEffect(GraphicsDevice);  
basicEffect.VertexColorEnabled = true;  
basicEffect.LightingEnabled = false;  
basicEffect.Projection = Camera.Projection;

// draw code
GraphicsDevice.RasterizerState = RasterizerState.CullNone;
GraphicsDevice.SetVertexBuffer(vertexBuffer);

foreach (EffectPass p in basicEffect.CurrentTechnique.Passes)
{
   p.Apply();
   GraphicsDevice.DrawUserPrimitives<VertexPositionColor>(PrimitiveType.TriangleStrip, vertexList, 0, 2);
}

As you can see, I've used different colors for all four vertexes, but the program actually seems to draw only two of them: vertexList[0] and vertexList[1]. Any suggestion? What's wrong?

Answer 1

I think you're missing

basicEffect.View = Camera.View;