From 3be1029a98aa0a85583f4e66a76a3a241c2b39f5 Mon Sep 17 00:00:00 2001
From: Théo de la Hogue
Date: Tue, 5 Sep 2023 12:48:32 +0200
Subject: Improving ar pipeline documentation and demonstration.

---
 docs/img/aruco_scene.png                           | Bin 11903 -> 13704 bytes
 .../aruco_scene_creation.md                        | 131 +++++++++++++++++++++
 .../augmented_reality_pipeline/introduction.md     |  19 +++
 3 files changed, 150 insertions(+)
 create mode 100644 docs/user_guide/augmented_reality_pipeline/aruco_scene_creation.md
 create mode 100644 docs/user_guide/augmented_reality_pipeline/introduction.md

(limited to 'docs')

diff --git a/docs/img/aruco_scene.png b/docs/img/aruco_scene.png
index 611676e..eee548d 100644
Binary files a/docs/img/aruco_scene.png and b/docs/img/aruco_scene.png differ
diff --git a/docs/user_guide/augmented_reality_pipeline/aruco_scene_creation.md b/docs/user_guide/augmented_reality_pipeline/aruco_scene_creation.md
new file mode 100644
index 0000000..ce080ca
--- /dev/null
+++ b/docs/user_guide/augmented_reality_pipeline/aruco_scene_creation.md
@@ -0,0 +1,131 @@
+Setup ArUco markers scene
+=========================
+
+The OpenCV library provides a module to detect fiducial markers into a picture and estimate its pose (cf [OpenCV ArUco tutorial page](https://docs.opencv.org/4.x/d5/dae/tutorial_aruco_detection.html)).
+
+![OpenCV ArUco markers](https://pyimagesearch.com/wp-content/uploads/2020/12/aruco_generate_tags_header.png)
+
+The ArGaze [ArUcoMarkers submodule](../../argaze.md/#argaze.ArUcoMarkers) eases markers creation and description of their expected place for further camera pose estimation.
+
+## Print ArUco markers from a ArUco dictionary
+
+ArUco markers always belongs to a set of markers called ArUco markers dictionary.
+
+![ArUco dictionaries](../../img/aruco_dictionaries.png)
+
+Many ArUco dictionaries exist with properties concerning the format, the number of markers or the difference between each markers to avoid error in tracking.
+
+Here is the documention [about ArUco markers dictionaries](https://docs.opencv.org/3.4/d9/d6a/group__aruco.html#gac84398a9ed9dd01306592dd616c2c975).
+
+The creation of [ArUcoMarkers](../../argaze.md/#argaze.ArUcoMarkers.ArUcoMarker) pictures from a dictionary is illustrated in the code below:
+ 
+``` python
+from argaze.ArUcoMarkers import ArUcoMarkersDictionary
+
+# Create a dictionary of specific April tags
+aruco_dictionary = ArUcoMarkersDictionary.ArUcoMarkersDictionary('DICT_APRILTAG_16h5')
+
+# Export marker n°5 as 3.5 cm picture with 300 dpi resolution
+aruco_dictionary.create_marker(5, 3.5).save('./markers/', 300)
+
+# Export all dictionary markers as 3.5 cm pictures with 300 dpi resolution
+aruco_dictionary.save('./markers/', 3.5, 300)
+```
+
+Let's print some of them before to go further.
+
+!!! warning
+	Print markers with a blank zone around them to help in their detection.
+
+## Describe expected ArUco markers place
+
+Once [ArUcoMarkers](../../argaze.md/#argaze.ArUcoMarkers.ArUcoMarker) pictures are placed into a scene it is possible to describe their expected 3D place into a file.
+
+![ArUco scene](../../img/aruco_scene.png)
+
+What ever the origin is, all expected markers places need to be described in an [right-handed 3D axis](https://robotacademy.net.au/lesson/right-handed-3d-coordinate-frame/) where, from a camera point of view:
+
+* +X is pointing to the right,
+* +Y is pointing to the top,
+* +Z is pointing to camera side.
+
+!!! warning
+	All ArUco markers spatial values must be given in **centimeters**.
+
+### Edit OBJ file description
+
+OBJ file format could be exported from most 3D editors.
+
+``` obj
+o DICT_APRILTAG_16h5#0_Marker
+v -5.000000 14.960000 0.000000
+v 0.000000 14.960000 0.000000
+v -5.000000 19.959999 0.000000
+v 0.000000 19.959999 0.000000
+vn 0.0000 0.0000 1.0000
+s off
+f 1//1 2//1 4//1 3//1
+o DICT_APRILTAG_16h5#1_Marker
+v 25.000000 14.960000 0.000000
+v 30.000000 14.960000 0.000000
+v 25.000000 19.959999 0.000000
+v 30.000000 19.959999 0.000000
+vn 0.0000 0.0000 1.0000
+s off
+f 5//2 6//2 8//2 7//2
+o DICT_APRILTAG_16h5#2_Marker
+v -5.000000 -5.000000 0.000000
+v 0.000000 -5.000000 0.000000
+v -5.000000 0.000000 0.000000
+v 0.000000 0.000000 0.000000
+vn 0.0000 0.0000 1.0000
+s off
+f 9//3 10//3 12//3 11//3
+o DICT_APRILTAG_16h5#3_Marker
+v 25.000000 -5.000000 0.000000
+v 30.000000 -5.000000 0.000000
+v 25.000000 0.000000 0.000000
+v 30.000000 0.000000 0.000000
+vn 0.0000 0.0000 1.0000
+s off
+f 13//4 14//4 16//4 15//4
+```
+
+Here are common OBJ file features needed to describe ArUco markers place:  
+
+* Object lines (line starting with *o* key) indicate markers dictionary and id by following a format: **DICTIONARY**#**ID**\_Marker.
+* Vertice lines (lines starting with *v* key) indicate markers corners. The marker size will be automatically deducted from the geometry.
+* Plane normals (lines starting with *vn* key) need to be exported for further pose estimation.
+* Face (lines starting with *f* key) link vertices and normals indexes together.
+
+!!! warning
+	All markers must have the same size and belong to the same dictionary.
+
+### Edit JSON file description
+
+JSON file format allows to describe markers places using translation and euler angle rotation vectors.
+
+``` json
+{
+    "dictionary": "DICT_APRILTAG_16h5",
+    "marker_size": 5,
+    "places": {
+        "0": {
+            "translation": [-2.5, 17.5, 0],
+            "rotation": [0.0, 0.0, 0.0]
+        },
+        "1": {
+            "translation": [27.5, 17.5, 0],
+            "rotation": [0.0, 0.0, 0.0]
+        },
+        "2": {
+            "translation": [-2.5, -2.5, 0],
+            "rotation": [0.0, 0.0, 0.0]
+        },
+        "3": {
+            "translation": [27.5, -2.5, 0],
+            "rotation": [0.0, 0.0, 0.0]
+        }
+    }
+}
+```
diff --git a/docs/user_guide/augmented_reality_pipeline/introduction.md b/docs/user_guide/augmented_reality_pipeline/introduction.md
new file mode 100644
index 0000000..a06b1e2
--- /dev/null
+++ b/docs/user_guide/augmented_reality_pipeline/introduction.md
@@ -0,0 +1,19 @@
+Overview
+========
+
+This section explains how to build augmented reality pipelines based on ArUco Markers technology for various use cases.  
+
+First, let's look at the schema below: it gives an overview of the main notions involved in the following chapters.
+
+![Augmented reality pipeline](../../img/augmented_reality_pipeline.png)
+
+To build your own augmented reality pipeline, you need to know:
+
+* [How to setup an ArUco markers scene](aruco_scene_creation.md),
+* [How to deal with an ArCamera instance](ar_camera_configuration_and_execution.md),
+* [How to add ArScene instance](ar_scene.md),
+* [How to visualize ArCamera and ArScenes](visualisation.md)
+
+More advanced features are also explained like:
+
+* [How to script augmented reality pipeline](advanced_topics/scripting.md)
-- 
cgit v1.1