update README.md

Author: bimangle

README.md

@@ -2,7 +2,7 @@
 
 BimAngle Engine can export your model to other formats, such as **Autodesk Forge Viewer SVF/F2D**, **glTF/glb**, **Cesium 3D Tiles**, etc. No need to rely on other online services, can be run offline.
 
-BimAngle Engine has four versions so far, namely **RVT**, **NW** ,**DWG**, **DGN** and **SKP**.
+BimAngle Engine has six versions so far, namely **RVT**, **NW** ,**DWG**, **DGN**, **SKP** and **3DXML**.
 
 #### BimAngle Engine RVT
 The runtime environment is **Autodesk Revit** addin, support Autodesk Revit 2014-2023.
@@ -19,6 +19,9 @@ The runtime environment is **Bentley MicroStation CE** addin.
 #### BimAngle Engine SKP
 For *.skp(SketchUp model), no other software dependencies are required.
 
+#### BimAngle Engine 3DXML
+For *.3dxml, no other software dependencies are required.
+
 ## Quick start
 
 * Clone or download this repository
@@ -30,6 +33,7 @@ For *.skp(SketchUp model), no other software dependencies are required.
 * for BimAngle Engine **DWG**, just run it
 * for BimAngle Engine **DGN**, run MicroStation CE and load model, you can find export button in toolbar.
 * for BimAngle Engine **SKP**, just run it
+* for BimAngle Engine **3DXML**, just run it
 
 ## How to purchase licenses?
 Please contact liuyongsheng@msn.com