Merge pull request #133 from CesiumGS/update-readme-2024-05-25

Update README.md

README.md

@@ -14,6 +14,8 @@ If you want to work directly with a clone of the Git repository, see [Developer
 
 ## Command Line Usage
 
+> **Note:** All input- and output paths for the 3D Tiles Tools are _case sensitive_. Even though some operating systems (like Windows) usually do not differentiate between uppercase and lowercase, the file- and directory names that are given at the command line must exactly match the actual names.
+
 #### Common command line options for each function:
 
 |Flag|Description|Required|
@@ -52,13 +54,22 @@ npx 3d-tiles-tools ungzip -i ./specs/data/TilesetOfTilesets-gzipped/ -o ./output
 #### combine
 
 Combines all external tilesets into a single tileset.
+
+> **Note** about the difference between `merge` and `combine`: The `combine` command takes a tileset that already _refers_ to _external_ tilesets. And it creates a new tileset where the former _external_ tilesets are "inlined". So the result will be a single tileset, without external references.
+
+Example:
+
 ```
 npx 3d-tiles-tools combine -i ./specs/data/combineTilesets/input -o ./specs/data/combineTilesets/output
 ```
 
 #### merge
 
 Merge multiple tilesets into a single one that refers to the input tilesets as external tilesets.
+
+> **Note** about the difference between `merge` and `combine`: The `merge` command creates a _new_ tileset that _refers_ to the given ones as _external_ tilsets. This means that the resulting tileset is not complete _without_ the ones that are used as the inputs for the `merge` command.
+
+Example:
 ```
 npx 3d-tiles-tools merge -i ./specs/data/mergeTilesets/TilesetA -i ./specs/data/mergeTilesets/sub/TilesetA -o ./specs/data/mergeTilesets/output
 ```
@@ -101,11 +112,11 @@ When `--targetVersion 1.1` is given, then this will upgrade legacy tilesets to c
 - The `refine` value will be converted to be in all-uppercase.
 - glTF 1.0 models in B3DM or I3DM will be upgraded to glTF 2.0.
 - The `3DTILES_content_gltf` extension declaration will be removed.
-- PNTS, B3DM, and I3DM content will be converted to glTF.
+- PNTS, B3DM, I3DM, and CMPT content will be converted to glTF.
 
 > Implementation note:
 > 
-> The conversion of the legacy tile formats to glTF should be considered as a _preview feature_. There are corner cases where the conversion is not possible generically - for example, when I3DM tile content contains glTF data that contains _animations_. The conditions under which the conversion is possible may be specified more explicitly in the future. 
+> The conversion of the legacy tile formats to glTF should be considered as a _preview feature_. There are corner cases where the conversion is not possible generically - for example, when I3DM tile content contains glTF data that contains _animations_, or when a CMPT (indirectly) contains multiple glTF assets that already use the `EXT_structural_metadata` extension. The conditions under which the conversion is possible may be specified more explicitly in the future.