Question: I didnt quite understand whats is the `effect.World` and `effect.View` etc. and why we put the matricies in them?

```
foreach (ModelMesh mesh in model1.Meshes)
        {
            foreach (BasicEffect effect in mesh.Effects)
            {
                effect.World = Matrix.CreateWorld(Vector3.Zero, Vector3.Forward, Vector3.Up);
                effect.View = Matrix.CreateLookAt(Vector3.Zero, Vector3.Zero, Vector3.Up);
            }
        }

```

Answer: 
effect.World is not a matrix representing the world. It is a matrix representing a 3d object's (mesh, model) position and orientation relative to the 3d game world. Each object will have a different effect.World matrix if they are positioned differently &/or pointed differently.

effect.View is a matrix that represents (in an inverted form) the position & orientation of the camera relative to that same 3d game world. Most of the time, there is only one camera, but there can be more (say, a rear view mirror will have it's own view matrix as opposed to the main screen showing the view out the windshield of a car racing game).

1. a model's vertices are hard valued to model local space.
2. Then the effect.World transforms them to game world space.
3. then the effect.View transforms them to camera space.
4. Then the effect.Projection transforms them to 2d screen space and 'volia', your pixel shader knows where to draw what.
From MSDN;

[`BasicEffect.World`](http://msdn.microsoft.com/en-us/library/microsoft.xna.framework.graphics.basiceffect.world.aspx)

> 
> Gets or sets the world matrix. **Use this matrix to change the position
>  of the model, using world coordinates**.
> 
> 
> 

[`BasicEffect.View`](http://msdn.microsoft.com/en-us/library/microsoft.xna.framework.graphics.basiceffect.view.aspx)

> 
> Gets or sets the view matrix. **Use this matrix to change the position
>  and direction of the camera**.
> 
> 
> 

I think bold lines explain what is exactly their difference. Also I found some helpful articles;

* [How to: Use BasicEffect](http://msdn.microsoft.com/en-us/library/bb203926%28v=xnagamestudio.10%29.aspx)
* [Does every Entity in an XNA game need it's own BasicEffect instance?](https://gamedev.stackexchange.com/questions/36026/does-every-entity-in-an-xna-game-need-its-own-basiceffect-instance)
* [Understanding Half-Pixel and Half-Texel Offsets](http://drilian.com/2008/11/25/understanding-half-pixel-and-half-texel-offsets/)
* <http://blogs.msdn.com/b/shawnhar/archive/2010/04/05/spritebatch-and-custom-shaders-in-xna-game-studio-4-0.aspx>
* <http://msdn.microsoft.com/en-us/library/bb219690(VS.85).aspx>