Added README.md

README.md

@@ -1 +1,80 @@
-# freecad_to_gazebo
+# Freecad to Gazebo exporter
+
+## Introduction
+Freecad to gazebo exporter is a tool for exporting freecad assembly project to gazebo/ros model.
+
+## Design Rules
+This project is in its early stage therefore specific design rules must be followed to work with it.
+* The assmbly file must be created with `A2Plus` (freecad's prefered assembly workspace).
+* Parts of the assembly must be in separate files.
+* Imovable parts of the main assembly must be made in separate subasssemblies.
+* Joints should be represented by AxisConsident constraints with lock rotation turned off.
+* For URDF files to work properly, tree structure must be maintained (ie. parent and childs of constraints must follow tree structure).
+
+## Requirements
+* [Freecad][freecad] with [A2Plus][a2plus] workspace installed
+* [ROS][ros] *Optional*, If you wish to install it as a package
+
+## Usage
+
+#### Clone the repository to catkin workspace
+```console
+$ git clone https://github.com/Dave-Elec/freecad_to_gazebo.git ~/catkin_ws/src
+```
+
+#### Re-build catkin workspace
+```console
+$ catkin_make
+$ source devel/setup.bash
+```
+
+#### To generate only SDF model from freecad assembly:
+```console
+# freecad_to_gazebo.py <assembly_file> <path/to/model_dir> --sdf
+```
+
+#### To generate SDF and URDF model from freecad assembly:
+```console
+$ freecad_to_gazebo.py <assembly_file> <path/to/model_dir>
+```
+Note: Only links and joints are generated in the SDF model. to use the model with ros, use the URDF model.
+
+## Options
+```console
+$ freecad_to_gazebo.py <assembly_file> <path/to/model> [--sdf] [--noexport] [--config <path/to/config>]
+```
+
+**--sdf**: Export only SDF.
+
+**--noexport**: Don't export mesh files.
+
+**--config**: Use other configuration file. (default is `robot_config.json` inside a directory the same as the assembly file).
+
+
+## Example config file
+```json
+{
+    "name": "robot_name",
+    "joints_limits": {"upper": 90, "lower": -90, "effort": 1, "velocity": 5},
+    "transmission": {
+        "type": "transmission_interface/SimpleTransmission",
+        "hardware_interface": "hardware_interface/PositionJointInterface"
+    },
+    "joints_config": {
+        "type": "position_controllers/JointGroupPositionController",
+        "grouped": true
+    },
+    "joints_pid": {"p": 20.0, "i": 10.0, "d": 0.0, "i_clamp": 0.0},
+    "root_link": "base_link"
+}
+```
+
+## Future plans
+* Extend collada exporter to export materials from assemblies.
+* Create a FreeCAD workbench to interactively assign joints and export to gazebo.
+* Reduce set of design rules by making it more robust and general perpouse.
+* Support any valid structures of assemblies.
+
+[freecad]:https://freecadweb.org
+[a2plus]:https://github.com/kbwbe/A2plus
+[ros]:https://ros.org