Merge branch 'juan.sardi-barzallo-master-patch-04652' into 'master'

Update README.md

See merge request !1

README.md

+# IFC → CityGML 3 with FME
+
+Transform building models from **IFC version 2x3 / IFC version 4x3** into **CityGML v3** for integration of BIM into urban-scale simulations and smart-city development.  
+Focus: interoperability of Building Information Modeling (BIM) data into city scale simulations, semantic fidelity, and robust data pipelines using **FME**.
+
+---
+
 ## Overview
 This project provides an FME-based workflow to convert BIM data (IFC) into CityGML 3.0 feature structures suitable for city-scale analytics (e.g., energy, occupancy, urban planning). It documents common interoperability challenges (geometry, semantics, CRS, level of detail) and proposes practical mitigation patterns.
 
@@ -25,10 +32,12 @@ This project provides an FME-based workflow to convert BIM data (IFC) into CityG
 
 > Use the repository above as a conceptual guide for class/property mappings and schema design when preparing FME SchemaMapper tables or custom writers.
 
+- Some literature references that may help understanding the challenge: https://isprs-archives.copernicus.org/articles/XLVI-4-W3-2021/287/2022/isprs-archives-XLVI-4-W3-2021-287-2022.pdf
+
 ---
 
 ## Environment Setup
-- Tools: FME (Free Student Edition) 
+- Tools: FME (Student license ) (request in advance) 
 - Data viewers: KIT (QGIS or CityGML viewer)  
 - Optional: Blender + Bonsai IFC add-on (for IFC visualization)  
 - OS: Mac / Windows