[Test]
public void RenderCoordinateSystemCross()
{
    CreateLookAtCamera(Vector3D.One * 4.0f, Vector3D.Zero);
    new Line3D(-Vector3D.UnitX, Vector3D.UnitX * 3, Color.Red);
    new Line3D(-Vector3D.UnitY, Vector3D.UnitY * 3, Color.Green);
    new Line3D(-Vector3D.UnitZ, Vector3D.UnitZ * 3, Color.Blue);
}

[Test]
public void RenderCoordinateSystemCross()
{
    CreateLookAtCamera(Vector3D.One * 4.0f, Vector3D.Zero);
    new Line3D(-Vector3D.UnitX, Vector3D.UnitX * 3, Color.Red);
    new Line3D(-Vector3D.UnitY, Vector3D.UnitY * 3, Color.Green);
    new Line3D(-Vector3D.UnitZ, Vector3D.UnitZ * 3, Color.Blue);
}

[Test]
public void RenderGrid()
{
    const int GridSize = 10;
    const float GridScale = 0.5f;
    const float HalfGridSize = GridSize * 0.5f;
    var axisXz = new Vector2D(-HalfGridSize, -HalfGridSize);
    CreateLookAtCamera(Vector3D.One * 4.0f, Vector3D.Zero);
    for (int i = 0; i <= GridSize; i++, axisXz.X += 1, axisXz.Y += 1)
    {
        new Line3D(new Vector3D(-HalfGridSize * GridScale, axisXz.Y * GridScale, 0.0f),
            new Vector3D(HalfGridSize * GridScale, axisXz.Y * GridScale, 0.0f), Color.White);
        new Line3D(new Vector3D(axisXz.X * GridScale, -HalfGridSize * GridScale, 0.0f),
            new Vector3D(axisXz.X * GridScale, HalfGridSize * GridScale, 0.0f), Color.White);
    }
}

[Test]
public void RenderGrid()
{
    const int GridSize = 10;
    const float GridScale = 0.5f;
    const float HalfGridSize = GridSize * 0.5f;
    var axisXz = new Vector2D(-HalfGridSize, -HalfGridSize);
    CreateLookAtCamera(Vector3D.One * 4.0f, Vector3D.Zero);
    for (int i = 0; i <= GridSize; i++, axisXz.X += 1, axisXz.Y += 1)
    {
        new Line3D(new Vector3D(-HalfGridSize * GridScale, axisXz.Y * GridScale, 0.0f),
            new Vector3D(HalfGridSize * GridScale, axisXz.Y * GridScale, 0.0f), Color.White);
        new Line3D(new Vector3D(axisXz.X * GridScale, -HalfGridSize * GridScale, 0.0f),
            new Vector3D(axisXz.X * GridScale, HalfGridSize * GridScale, 0.0f), Color.White);
    }
}

[Test]
public void RenderRedLine()
{
    CreateLookAtCamera(Vector3D.UnitY, Vector3D.Zero);
    new Line3D(-Vector3D.UnitX, Vector3D.UnitX, Color.Red);
}

[Test]
public void RenderRedLine()
{
    CreateLookAtCamera(Vector3D.UnitY, Vector3D.Zero);
    new Line3D(-Vector3D.UnitX, Vector3D.UnitX, Color.Red);
}