Assuming you have already done this:
Start up Mount and Blade and click configure on the start up screen to warband then go to advanced and tick edit mode. Ignore the brackets next to it saying it slows down the game, that only really applies to when your editing.
I will begin.
Setup- Just to familiarize yourself with it you can edit ruins multiplayer map. So make a copy of native and then run that copy. Go to multiplayer, host a game on the ruins map and just select spectator.
- Okay now you need to follow these two things, it is what you will do every time you scene edit.
1. Simply press "Alt+Enter" to go into windowed mode
2. Press "Ctrl+E" to open up edit mode.
- Well done you are now in the scene edit menu

(The camera will probably spawn you in the corner of the map) just move around with W-A-S-D and click and drag to rotate around. If you see bright red and green squares these are the invisible barriers. The yellow arrows are entry points or "spawn points" the numbers mean different things depending on the scene. Check
here for info in them for multiplayer. But leave that for now
- It may be a good idea to drag the menu window to the right side of the screen.
Edit Objects- Now the menu on the side should be showing you a list of scene props in a scroll box.
- Select arabian_castle_battlement_a for starters.
- Then click the "Add Object" button.
- Now the battlement is ready for placement, just move your cursor around and whilst navigating the scene look for a place to put it. To place an object right click and it will lock in place.
- But of course you need to know these controls:
Hold down:
U: and move the mouse left and right to rotate the item, when you have rotated it to the right angle simply release it.
T: Moves it up and down
X: Rotates on the X-axis
Y: Rotates on the Y-axis
Z: rotates on the Z Axis
R: Reverts it back to its unchanged form
Note: If it is highlighted orange then you have it selected, hold Ctrl and right click to select multiple things.
If you have placed an item and are unhappy with where it has been placed select it again with right click then hold G to move it around again.
- To stop adding objects click the "Add Object" button again.
- Now that you know how to spawn objects have a scroll through the list (it is very long) and see what is in there. If you see something interesting then add it in to see what it is. This way you familiarize yourself with the selection.
Hint: If you have the "Add Object" button selected you can use the up and down keys to scroll through the selection. So you can see each item in front of you.
- If you want to remove a scene prop altogether then right click it and hit delete.
Now you are probably feeling pretty good about your new ability to scene edit but lets look at the rest of the menu.
- Down the bottom you will notice weather controls, ignore those they do not actually edit the weather for the scene it is only for previews.
- Above the scene props selection box there is another box which will probably have Entry point 0 as its first entry. This is a list of added scene props, if you double click on one it will take you to it but be warned it is often known to crash the game. It is best to avoid doing that unless necessary.
- Higher up you will notice boxes which have "Scale" and Pos X (Z and Y) this is the placement information of the selected scene prop, assuming you have one selected. If you don't select something now. In the scale box edit the top number to 2.0 instead of 1.0 and see how the selected scene prop stretches in a direction. This way you can make things bigger than originally made. It can really help if a door does not quite fit the opening for example. - Ignore the "Var No:" to be honest I don't know what it does.
Good luck
Some useful addition:
Scene editing is not exactly stable. It is known to crash, I get freezes all the time and if it freezes then just be glad it has not crashed. It is normal. But you are editing the scene to the mod but the scene is saved in scene_obj folder of the mod. If you edited the ruins map for example go into Scene Obj folder and search for "scn_multi_scene_1", and that is your edited scene.
Unfotunately not all the scene information is saved there, the terrain is saved somewhere else.
In scenes.txt of the mod search for multi_scene_1
scn_multi_scene_1 multi_scene_1 256 none none 0.000000 0.000000 100.000000 100.000000 -100.000000 0x000000013003d7e30005053f00003b4e0000146300006e84
0
0
outer_terrain_beach
the bolded bit is the terrain code, I need that information to put your map in game.
So if you wanted to give somebody the edited ruins map for example you would send him the "scn_multi_scene_1" and the numbers highlighted.
The rest is up to him to add it in