Well, now that we have this spring break, I can spend more time working with my engine and doing some cool tutorials for this blog. Yuppie! :)

Nice, isn't it?? Visit Randomchaos 3DEngine blog. Thanks to Charles Humphrey for his code!

Warning: I have not tested any of this code. I've done it in my engine, but on another way so it's compatible with it. If you find any bugs, or you want to add something, say it! Thanks! Now, read up...
And also, these tutorials assume you have some knowledge in C#, and you know how to work with arrays and lists...

What is collision detection??? Well, without it, a model could pass through another model, bullets wouldn't collide with walls, enemies etc... It's very hard to do vertex perfect collisions, so, models are presented with boxes or spheres. XNA has BoundingBox and BoundingSphere classes, which we'll use to detect collision between different objects. So, here we go.
Create a new class called BoundingGroup. That class will do anything for us, it will first create the main bounding box, and then for each mesh in meshes, it will create a bounding box just for that mesh. First some variables:

private BoundingBox boundingBox = new BoundingBox();
private List boundingBoxes = new List();
private Matrix[] Transforms;

These variables will hold our main bounding box, and a list of our small bounding boxes and the transforms. Now make a method called CalculateBoxes(Model model) which looks like this:

http://paste.lisp.org/display/43066

That's all you need to do to get the bounding boxes, but, that's not all. You also need a field, to get the bounding boxes, and while getting them, you need to transform them to the current object position. So, for that, we'll use a method, and not a field.

http://paste.lisp.org/display/43066#1

And you should add a empty constructor BoundingGroup() just in case...
Now, to learn to use it. When you load the graphics content, and when you load your model, make a new bounding group, and then call CalculateBoxes method passing the model you just loaded.
When you check for collisions, check the main bounding boxes first, and if there is collision, check everything else. To check for collisions, use the BoundingBox.Intersects method.

In the next tutorials, you'll see how to get bounding spheres from the models you want...

And of course, do not stop with this. You see that you need to pass the objects position, rotation and scaling everytime you want to get the boxes. Try to edit the class so you will bind it to a object, and then you won't need to pass the values, just read them from the object (that's what I did).

How do you like it?? :) Better than it was
I'm preparing a little tutorial on collision detection, so, stay tuned...

It's been a long time since my last post... I've been busy, went on some competitions from B.O.E. (Basics Of Electrotechnics) and, I'm first in my country (lool :)). Now I can get back to my projects!
Long time has passed since my last post, so you probably need to know some things. The Speeder 2 project has been paused(not stopped!) because I need 3D models. But that's not the only reason. I've changed my engine structure, rewritten the whole engine from scratch. Now it's even more powerfull. Some things were kicked from the engine, like Nuclex Fonts, because XNA Refresh 1.0 has font support.
Because I needed models, I've started a little project called PacKiller where I can make everything I need, so I don't depend on anyone :)
Screen
It's a FPS where you will have to save the world from pacman angels, except, they aren't angels anymore... They've switched sides :)

Later...

Here's the NInput class, in which you can see how to process input. This class is different from The Hazy Mind class in some things like you can read the scroll wheel value etc... Suite it to your needs :)

http://paste.lisp.org/display/40867

The way you use the class: first, create a new object:

NInput input = new NInput();
input.Initialize();

and everytime the frame is updated call

input.Updat(gameTime);

To check for keys:

input.Keys.Contains(Keys.A);

for mouse buttons

input.MouseButtons[0] - left mouse button
input.MouseButtons[1] - middle mouse button
input.MouseButtons[2] - right mouse button

e.g. if (input.MouseButtons[0] == ButtonState.Pressed)

:)

Also, I forgot to mention, set the ViewportCenterX and ViewportCenterY to WindowWidth / 2 and WindowHeight / 2

Well, here's a link to the class

http://paste.lisp.org/display/40830

I will not post the GUI Manager class because I need to modify it a little... Be patient :) So, how to use the class without the GUI Manager. Firstly you need to create it, something like this:

NGUIButtonSimple button = new NGUIButtonSimple(someArgs)

someArgs are arguments you are passing to the function, there are lots of them and they're all explained in the class. Also, you need to modify the class to use the texture you want, but you'll handle it :) If you have any questions, post a comment and it's done! Now, let's go on.

Here's also the NIGUIControl interface

http://paste.lisp.org/display/40832

The next step is whenever your engine is updated, you call the UpdateMouse class. I will also put up my input class later, but for now you will need to change that method.

And everytime you draw, call the RenderControl method, you also need to give it a active sprite batch.
If you change resolution, and want to update the control so it changes its width and height, call the SetResolutionFactor method. The resolution factor is a Vector2, and you can calculate a resolution factor like this:

http://paste.lisp.org/display/40832#1

Well, think that's it :)