is it possible to let mged show the world coordinates on the graphics window? Because if i make
it gives me some coordinates but i have no idea, which point is on which place..
thanks in advance. :)
There's a couple things you can do - you can turn on the "Faceplate" via the Misc menu, which is probably what you're looking for. That will show what point is centered on the view, the size of the view, and other useful information. Also, you can turn on the Model or View axes via the Modes->Axes menu which will then draw and label axes at the global (0,0,0) and view origins respectively.
Thank you very much. Both tools are very useful for me. Now if there are also some rulers, it would be awesome. :D
Ruler is under Settings->Grid->Draw Grid. You can change the spacing as well as the anchor point (ruler origin) and snapping.
More interactive and flexible is the "ADC" angle distance cursor, but it's also more of an advanced modeling topic. There are docs on the website in the Principles of Effective Modeling tutorial that go into more detail.
Another trick that might help, if you go into edit mode on an object, a primitives parameters will be displayed. Just be careful using the mouse once you go into edit mode because it will modify the primitive, not the view (that behavior can be changed on the menu).
make sph sph