readme

README.md

@@ -1,6 +1,17 @@
 # 3d-render
 
-## `.obj` files
+## Files
+
+This program use two kind of files to represent a 3D world:
+- `obj` which are a list of planes representing an object.
+- `map` which are a list of object representing the the world itself.
+
+Only one map file can be use at time and a map can reference other maps.
+Anything in a map is relative to the base point of the map, which is (0, 0, 0) for the 'top map' contain everything else. A map point is fix a can't be negative. An object point is relative to the map point and can be negative.
+
+### `.obj` files
+
+0,0,0 is the bottom-left-front point of the object. It is used to translate the object in the 3D map.
 
 Syntaxe
 ```
@@ -16,17 +27,19 @@ OBJECT
 
 ```
 
-## `.map` files
+### `.map` files
+
+Calling a map file from a map file will change the reference point of the called map from fixed to relative to the current map.
 
 Syntaxe
 ```
 MAP <- header
-Call object file -> x,y,z <- object position : name <- Object name
+Call object/map file: x,y,z <- object position : filename
 ```
 
 Example
 ```
 MAP
-1,5,0:cube
-2.3,2.0,6:light
+1,5,0:cube.map
+2.3,2.0,6:light.obj
 ```