I would create my own 3d game editor. All i need to do is load mesh files (.x) and translate/rotate/scale at the last set some proprety as Bounding box. In this way i can define a new world. How can i starting? How could i save it so to use in my game?

I am working on a level editor for a university project myself
and I can tell you it's not that easy. But it's also not impossible and it may be neccessary if you are developing a game.
But remember if your game is a hobby project, maybe you can use an already existing map editor!
If you are sure you want to spend a lot of time developing an editor then here are some thoughts I came up with for my project:
(I assume you are developing for Windows)

- The editor should run the engine of the game in it's work space, so
all features of the game (like Normal-Mapping etc.) run in the editor as well.

- I would recommend C# for developing the editor (windows, controls etc.) because it is perfect for that, but your game engine may be unmanaged C++ (as in my case) so you would have to call unamanged code from your managed editor.
It is possible but I guess it's not very easy AND things in the engine woun't work automatically in your editor (you would have to write a wrapper for the unmanaged code first)

- So you are left with writing you editor in unmanged C++ - normal Win32 API programming. I used the WTL because it gives me a little bit of object orientation. But I think it's hard work to get a editor running with the Win32 API if you don't have much experience in that field.

- The level files are saved in xml format because ther are parsing libraries on the web I can use and our files are not so big that xml becomes a speed problem.

Here is a screenshot of an early version of my editor so you see that I know what I am talking about :)

-- Constantin

I know C# i could create the editor with this lanaguage and .NET framework, but to handle:
"ray picking" and/or "ray projecting", so that you can convert the 2D mouse coordinates into 3D data that you can translate/rotate from. You might also want to look into "Arc Ball Camera" for that familiar 3D editor navigation feel.
can someone suggestme about?

Quote:Original post by Supernat02
I think you would do best to have some sort of graphical interface like C#.

C# only works out well if you plan to write our games in a managed language, too.
.NET has very poor interop abilities with C++ (e.g. only works through COM or MC++ wrappers → lots of unnecessary work).
I'm fine with MFC, though any UI framework like wxWindows or GTK works well, too.

Sasuko:

First of all you will want to create some kind of game engine, e.g. a code base that is shared between game(s) and editor. This includes resource handling (loading meshes, materials and possibly scripts) and basic rendering services.
It's best to create a static library or a dll for this code. This way you can be sure that editor and game(s) are in sync and share equal functionality.

The basic steps are
1) create a detailed list of features you need (put in as much detail as you can - helps you to stay focused)
2) assign priorities to the items you've got from the list in 1)
3) implement a basic UI framework that has a preview window for rendering and a menu
4) implement the top priority items first (e.g. load a mesh, position/scale/rotate it and save to file).
5) test the functions by loading the created output into a simple viewer that shares the engine code
6) remove completed items from the list
7) goto step 4) until list is empty [smile]

how can i implement the toutch controll?
How can enstable when/whether i've cliccked on a vertex or a face of a mesh?

Quote:Original post by Link
how can i implement the toutch controll?
How can enstable when/whether i've cliccked on a vertex or a face of a mesh?

Do you really want/need to edit meshes physically? It can get quite complicated if you want to do that...

i don't want edit mesh but just can rotate/translate/scale.
How can i intercept the mesh, how by click select it, or its vertex or face?
Link i've your same interests.