update

ros/env.md

@@ -0,0 +1,23 @@
+# ros base env
+
+
+
+## use py3 with ros
+
+```bash
+
+source ...../python3
+pip install catkin_pkg pyyaml empy rospkg numpy
+mkdir -p catkin_ws/src      # 用户开发目录
+cd catkin_ws
+catkin_make
+
+cd ~
+mkdir -p catkin_base/src    # 第三方包编译目录
+cd catkin_base/src 
+git clone https://github.com/ros/geometry
+git clone https://github.com/ros/geometry2
+cd ..
+catkin_make
+
+```

ros/errors.md

@@ -0,0 +1,22 @@
+# errors
+
+
+
+### error1
+
+```bash
+-- +++ processing catkin package: 'tf2_bullet'
+-- ==> add_subdirectory(geometry2/tf2_bullet)
+-- Found PkgConfig: /usr/bin/pkg-config (found version "0.29.1") 
+-- Checking for module 'bullet'
+--   No package 'bullet' found
+CMake Error at /usr/share/cmake-3.5/Modules/FindPkgConfig.cmake:367 (message):
+  A required package was not found
+Call Stack (most recent call first):
+  /usr/share/cmake-3.5/Modules/FindPkgConfig.cmake:532 (_pkg_check_modules_internal)
+  geometry2/tf2_bullet/CMakeLists.txt:7 (pkg_check_modules)
+
+```
+
+
+> sudo apt install libbullet-dev