Im making a 3d Tetris game for school
The wrong drawing

as you can see the back textures of the cubes is coming in front of the front textures of the cube.
Can anyone see whats wrong.
I'm using Models but before this i tried it with VertexPositionNormalTexture and that gave the exact same result. So i think i must look somewhere else. But im a beginner in XNA and im lost atm.

please help :)

It looks like you are using SpriteBatch to draw some text, so you might have to reinstate the render states below before drawing your cubes.

    GraphicsDevice.RenderState.DepthBufferEnable = true;
    GraphicsDevice.RenderState.AlphaBlendEnable = false;
    GraphicsDevice.RenderState.AlphaTestEnable = false;

Depending on your 3D content, you may also want to set:

    GraphicsDevice.SamplerStates[0].AddressU = TextureAddressMode.Wrap;
    GraphicsDevice.SamplerStates[0].AddressV = TextureAddressMode.Wrap;

See here for full explanation.

You probably just need to turn on the depth buffer just before doing the 3d rendering:

GraphicsDevice.RenderState.DepthBufferEnable = true;

I think it defaults to ON, but using the SpriteBatch without saving the state will turn it off again.

---EDIT---
Beaten by quick draw Craig :)

Thnx for the quick reply
it worked perfectly.
See below
Better drawing

as you can see @ the bottom of the cubes there is sometimes some small parts missing
as i zoom in these things get smaller .
Any ideas on that?

You might want to put your 2D drawing code after your 3D drawing code, as currently all the messages are behind the 3D objects.;)

yeah i know  ;)
the text is not correct positioned also atm.
but i want to fix the thingies on the bottom of the cubes.

That looks a little bit like Z-fighting. Do you render two cubes in each location perchance?

No only 1.

Have you fixed this yet? If not can you post your draw code so we can try spot something?

no its still the same
as http://filedump.sargeman.nl/gooddrawing.JPG
will post some more info tonight. im @ work now

i saw i left my computer on @ home

Do those strange grey bits flicker around if you move the camera or objects? If so, I'm even more sure it's Z-fighting. It looks like your textured cubes are fighting with some non-textured cubes. Maybe your Draw() is actually being called multiple times with the same Vector2 position in a single frame? Try drawing only a single brick and debug step though to confirm this isn't the case.

well i searched and checked but im not drawing anything twice.
I will try now to draw 1 block and then 2 etc.

it already happens with 1 model i just found out.
Could it be the model it self?
i'll try to make my own model and see if it works.

Yes it certainly does look like z-fighting.

Maybe the model has two cubes in it of the same size or has corrupted indices.

I would also turn off AlphaBlendEnable and AlphaTestEnable just to be sure its not doing anything weird.

Yeah i tried it with alphablend off but thats not helping and i also need it because the shadow shapes have transparent textures.
Ok i tried creating a cube model, but im really noob @ blender. i tried a tutorial with blender and xna but that gives me a huge cube and the textures of that cube are even more messed up

but i can tell one thing that its not the model
the model itself works fine in original game from a friend of mine.

ok i fixed it :D

changed
projectionMatrix = Matrix.CreatePerspectiveFieldOfView(MathHelper.PiOver4,
                                                                    aspectRatio,
                                                                    0.0001f, 1000);

to

projectionMatrix = Matrix.CreatePerspectiveFieldOfView(MathHelper.PiOver4,
                                                                    aspectRatio,
                                                                    1, 1000);

i guess nearplaneDistance was to small
thnx everyone for help