From 5fc3c70d2f6013e692ec165e39970302ded08e27 Mon Sep 17 00:00:00 2001
From: SamerKhshiboun <samer.khshiboun@intel.com>
Date: Thu, 13 Apr 2023 11:59:22 +0300
Subject: [PATCH] add info about extrinsic msg format in Extrinsics.msg and
 README.md

---
 README.md                                 | 14 +++++++++++++-
 realsense2_camera_msgs/msg/Extrinsics.msg |  5 +++--
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/README.md b/README.md
index b13f2e0537..b7254e7ecc 100644
--- a/README.md
+++ b/README.md
@@ -336,7 +336,15 @@ The `/diagnostics` topic includes information regarding the device temperatures
 ```
 administrator@perclnx466 ~/ros2_humble $ ros2 topic echo /camera/extrinsics/depth_to_color
 rotation:
-...
+- 0.9999583959579468
+- 0.008895332925021648
+- -0.0020127370953559875
+- -0.008895229548215866
+- 0.9999604225158691
+- 6.045500049367547e-05
+- 0.0020131953060626984
+- -4.254872692399658e-05
+- 0.9999979734420776
 translation:
 - 0.01485931035131216
 - 0.0010161789832636714
@@ -344,6 +352,10 @@ translation:
 ---
 ```
 
+- Extrinsic msg is made up of two parts:
+  - float64[9] rotation  (Column - major 3x3 rotation matrix)
+  - float64[3] translation  (Three-element translation vector, in meters)
+
 <hr>
 
 <h3 id="topics">
diff --git a/realsense2_camera_msgs/msg/Extrinsics.msg b/realsense2_camera_msgs/msg/Extrinsics.msg
index 565aa97781..53c886e697 100644
--- a/realsense2_camera_msgs/msg/Extrinsics.msg
+++ b/realsense2_camera_msgs/msg/Extrinsics.msg
@@ -1,2 +1,3 @@
-float64[9] rotation
-float64[3] translation
+# Cross-stream extrinsics: encodes the topology describing how the different devices are oriented
+float64[9] rotation  # Column - major 3x3 rotation matrix
+float64[3] translation  # Three-element translation vector, in meters