I'm creating an application which allows the user to manipulate 3D models.
I would like to draw 3 axis representing the world coordinate system in 3D in order to give the user an idea where he is. These axis are represented by a 3D model. Now I want these axis to be always shown at the bottom left of the screen. I know how to draw them but not how to project them at specific coordinates on the screen.
How can i achieve this?
I use XNA. The axes have been created with 3DSMax, each axes is a cylinder surmounted by a cone. When I load the 3DSMax file, I get an instance of the Model class.
I've just tried to draw it normally and it appears at the center of the scene. After that, i don't know what to do to make it appears at the bottom left of the screen regardless of where the camera looks, as if that was part of the UI. 3DSMax has the same thing at the bottom left of each frame.