diff --git a/01.curriculum/01.physics-chemistry-biology/03.niv3/02.geometrical-optics/03.reflexion-refraction-raytracing/03.ray-tracing/textbook.en.md b/01.curriculum/01.physics-chemistry-biology/03.niv3/02.geometrical-optics/03.reflexion-refraction-raytracing/03.ray-tracing/textbook.en.md
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--- a/01.curriculum/01.physics-chemistry-biology/03.niv3/02.geometrical-optics/03.reflexion-refraction-raytracing/03.ray-tracing/textbook.en.md
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----
-title: 'Ray tracing'
-slug: ray-tracing
----
-
-#### course to build
-
-<!-- ideas :
-
-1) ray tracing is a method for calculating the path of waves or particles through a system with regions of varying propagation velocity, absorption characteristics, and reflecting surfaces
-
-2) not describe phenomena such as interference and diffraction, which require wave theory 
-
-3) methods and software
-
--->
diff --git a/01.curriculum/01.physics-chemistry-biology/03.niv3/02.geometrical-optics/03.reflexion-refraction-raytracing/03.ray-tracing/textbook.fr.md b/01.curriculum/01.physics-chemistry-biology/03.niv3/02.geometrical-optics/03.reflexion-refraction-raytracing/03.ray-tracing/textbook.fr.md
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--- a/01.curriculum/01.physics-chemistry-biology/03.niv3/02.geometrical-optics/03.reflexion-refraction-raytracing/03.ray-tracing/textbook.fr.md
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@@ -1,16 +0,0 @@
----
-title: Ray-tracing
-slug: ray-tracing
----
-
-#### cours à construire
-
-<!--  idées:
-
-1) Le lancer de rayons est une méthode permettant de calculer le trajet des ondes ou des particules dans un système comportant des régions de vitesses de propagation variables, des caractéristiques d’absorption et des surfaces réfléchissantes.
-
-2) ne décrivent pas des phénomènes tels que les interférences et la diffraction, qui nécessitent la théorie des ondes.
-
-3) méthodes et logiciels (gratuits et professionnels)
-
--->
diff --git a/01.curriculum/01.physics-chemistry-biology/03.niv3/02.geometrical-optics/03.reflexion-refraction-raytracing/03.ray-tracing/topic.es.md b/01.curriculum/01.physics-chemistry-biology/03.niv3/02.geometrical-optics/03.reflexion-refraction-raytracing/03.ray-tracing/topic.es.md
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--- a/01.curriculum/01.physics-chemistry-biology/03.niv3/02.geometrical-optics/03.reflexion-refraction-raytracing/03.ray-tracing/topic.es.md
+++ /dev/null
@@ -1,17 +0,0 @@
----
-title: 'Ray tracing'
-slug: ray-tracing
----
-
-#### Curso que hay que construir
-
-<!--ideas :
-
-ideas:
-1) el trazado de rayos es un método para calcular la trayectoria de ondas o partículas a través de un sistema con regiones de velocidad de propagación variable, características de absorción y superficies reflectantes.
-
-2) no describe fenómenos como la interferencia y la difracción, que requieren la teoría de la onda.
-
-3) Métodos y software (gratuitos y profesionales).
-
--->
diff --git a/01.curriculum/01.physics-chemistry-biology/03.niv3/02.geometrical-optics/03.reflexion-refraction-raytracing/04.reflexion-refraction-overview/03.reflexion-refraction-beyond/annex.en.md b/01.curriculum/01.physics-chemistry-biology/03.niv3/02.geometrical-optics/03.reflexion-refraction-raytracing/04.reflexion-refraction-overview/03.reflexion-refraction-beyond/annex.en.md
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--- a/01.curriculum/01.physics-chemistry-biology/03.niv3/02.geometrical-optics/03.reflexion-refraction-raytracing/04.reflexion-refraction-overview/03.reflexion-refraction-beyond/annex.en.md
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----
-title: 'new course : beyond'
----
-
-new course : beyond
\ No newline at end of file
diff --git a/01.curriculum/01.physics-chemistry-biology/03.niv3/02.geometrical-optics/03.reflexion-refraction-raytracing/04.reflexion-refraction-overview/03.reflexion-refraction-beyond/annex.es.md b/01.curriculum/01.physics-chemistry-biology/03.niv3/02.geometrical-optics/03.reflexion-refraction-raytracing/04.reflexion-refraction-overview/03.reflexion-refraction-beyond/annex.es.md
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--- a/01.curriculum/01.physics-chemistry-biology/03.niv3/02.geometrical-optics/03.reflexion-refraction-raytracing/04.reflexion-refraction-overview/03.reflexion-refraction-beyond/annex.es.md
+++ /dev/null
@@ -1,5 +0,0 @@
----
-title: 'nuevo curso: más allá'
----
-
-nuevo curso: más allá
\ No newline at end of file
diff --git a/01.curriculum/01.physics-chemistry-biology/03.niv3/02.geometrical-optics/03.reflexion-refraction-raytracing/04.reflexion-refraction-overview/03.reflexion-refraction-beyond/annex.fr.md b/01.curriculum/01.physics-chemistry-biology/03.niv3/02.geometrical-optics/03.reflexion-refraction-raytracing/04.reflexion-refraction-overview/03.reflexion-refraction-beyond/annex.fr.md
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--- a/01.curriculum/01.physics-chemistry-biology/03.niv3/02.geometrical-optics/03.reflexion-refraction-raytracing/04.reflexion-refraction-overview/03.reflexion-refraction-beyond/annex.fr.md
+++ /dev/null
@@ -1,5 +0,0 @@
----
-title: 'nouveau cours : au-delà'
----
-
-nouveau cours : au-delà
\ No newline at end of file