Update documentation including README

Author: pablode

README.md

@@ -11,7 +11,6 @@ Unlike...
  - [Apple's USDZ Tools](https://developer.apple.com/augmented-reality/tools/), it is open-source and freely available
 
 guc furthermore supports near-lossless material translation via the [MaterialX](https://github.com/AcademySoftwareFoundation/MaterialX) standard.
-Shading networks can be encoded as UsdShade and flattened for backwards compatibility.
 
 All glTF features except animation and skinning are implemented and get continuously tested in guc's [test suite](https://github.com/pablode/guc-tests).
 
@@ -26,7 +25,7 @@ All glTF features except animation and skinning are implemented and get continuo
 
 ### Build
 
-You need USD v23.11+ (e.g. <a href="https://github.com/PixarAnimationStudios/OpenUSD/releases/tag/v24.03">v24.03</a>) with MaterialX support enabled.
+You need USD v23.11+ (e.g. <a href="https://github.com/PixarAnimationStudios/OpenUSD/releases/tag/v24.05">v24.05</a>) with MaterialX support enabled.
 
 Do a recursive clone of the repository and set up a build folder:
 ```
@@ -46,8 +45,6 @@ cmake --build . -j8 --config Release
 
 > Note: set `BUILD_SHARED_LIBS` for shared builds, and `CMAKE_MSVC_RUNTIME_LIBRARY` to USD's MSVC ABI.
 
-> Note: if module or shared libary loading fails, try building USD with the `--opencolorio` flag.
-
 ### Usage
 
 ```
@@ -68,8 +65,6 @@ Both glTF and GLB file types are valid input. USDA, USDC and USDZ formats can be
 
 An example asset conversion is described in the [Structure Mapping](docs/Structure_Mapping.md) document.
 
-> Note: imaging of USD+MaterialX assets may be incorrect due to a number of current [Ecosystem Limitations](docs/Ecosystem_Limitations.md).
-
 ### Extension support
 
 Name                                | Status&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
@@ -97,13 +92,14 @@ The _usdGlTF_ library implements USD's Sdf file format interface. Enable the `GU
 cmake --install . --component usdGlTF --config Release --prefix <USD_INSTALL_DIR>/plugin/usd
 ```
 
-> Note: the plugin only emits MaterialX materials if the `USDGLTF_ENABLE_MTLX` environment variable is set.
+glTF files can now be referenced as layers and opened with USD tooling.
+The _emitMtlx_ dynamic Sdf file format argument controls MaterialX material emission.
 
 ### License
 
 ```
 
-   Copyright 2022 Pablo Delgado Krämer
+   Copyright 2024 Pablo Delgado Krämer
 
    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.

docs/Ecosystem_Limitations.md

@@ -42,6 +42,9 @@ This issue affects a number of render delegates, including Pixar's [HdStorm](htt
 
 ## MaterialX in HdStorm
 
+#### Texture-coordinate related regression in USD v24.03+
+Issue [#3048](https://github.com/PixarAnimationStudios/OpenUSD/issues/3048) currently affects [multiple cases](https://github.com/pablode/guc-tests/commit/695f6dcc58c5b08b1d7b689dc1dc0c2d4305f154?diff=split&w=0) of the guc test suite.
+
 #### One and two channel sRGB texture formats are unsupported
 Converted assets may use such textures, but HdStorm is not able to render them. ([Source code](https://github.com/PixarAnimationStudios/USD/blob/3abc46452b1271df7650e9948fef9f0ce602e3b2/pxr/imaging/hdSt/textureUtils.cpp#L341-L345))
 

docs/Structure_Mapping.md

@@ -234,11 +234,8 @@ of MaterialX's `<normalmap>` node (see [Ecosystem Limitations](Ecosystem_Limitat
 
 There are a number of improvements that can be made to the mapping process.
 
-For instance, the MaterialX graph complexity can be reduced with the introduction
-of helper nodes, and color space related workarounds may be removed with proper support for attribute
-copying in HdMtlx (see [Ecosystem Limitations](Ecosystem_Limitations.md)).
-
-Resulting USD assets may make use of payloads, and in general, incremental changes
+For instance, the MaterialX graph complexity can be reduced with the introduction of helper nodes.
+Resulting USD assets could make use of payloads, and in general, incremental changes
 motivated by the [USD Asset WG Structure Guidelines](https://github.com/pablode/usd-wg-assets/blob/main/docs/asset-structure-guidelines.md) are to be expected.
 
 Lastly, user feedback is welcome in ensuring that assets conform to best practices.