Update readme and sample build script.

Author: kwokcb

javascript/README.md

@@ -8,14 +8,19 @@ This folder contains tests and examples that leverage the JavaScript bindings fo
 
 The emscripten SDK is required to generate the JavaScript bindings. There are several ways of using the SDK on different platforms. In general, we recommend to install the SDK directly, following the instructions below. Alternative options are explained [below](#alternative-options-to-use-the-emscripten-sdk).
 
-To install the SDK directly, follow the instructions of the [emscripten SDK installation Guide](https://emscripten.org/docs/getting_started/downloads.html#installation-instructions-using-the-emsdk-recommended). Make sure to install prerequisites depending on your platform and read usage hints first (e.g. differences between Unix / Windows scripts).
+To install the SDK directly, follow the instructions of the [emscripten SDK installation Guide](https://emscripten.org/docs/getting_started/downloads.html#installation-instructions-using-the-emsdk-recommended). Make sure to install prerequisites depending on your platform and read usage hints first (e.g. differences between Unix / Windows scripts). 
 
-Note that following the instructions will set some environment variables that are required to use the SDK. These variables are only set temporarily for the current terminal, though. Setting the environment variables in other terminals can be achieved by running
+The current supported version is `2.0.20`. Do not automatically update to the latest version to avoid build issues.
+
+Note that following the instructions will set some environment variables that are required to use the  SDK. These variables are only set temporarily for the current terminal, though. Setting the environment variables in other terminals can be achieved by running
 ```sh
 source ./emsdk_env.sh
 ```
 inside of the `emsdk` folder (check the documentation for the Windows equivalent). In case of the MaterialX project, it is not required to have these environment variables set. You can also use a CMake build flag instead, as described in the [build instructions](#build-steps) below.
 
+By default emsripten `2.0.20` will use an older version of NodeJs (`14.15.0`). It is recommended to use the version of NodeJs used to build the official release to avoid package compatibility or runtime issues. 
+The packages used are not currently compatible with version `18` of NodeJS.
+
 Setting the environment variables permanently is also possible, either by adding a `--permanent` flag to the `activate` command, or by sourcing the `emsdk_env` script every time a shell is launched, e.g. by adding the `source` call to `~/.bash_profile` or an equivalent file. Note however, that the environment variables set by the emscripten SDK might override existing system settings, like the default Python, Java or NodeJs version, so setting them permanently might not be desired on all systems.
 
 ### Alternative options to use the emscripten SDK
@@ -66,7 +71,7 @@ After building the project the `JsMaterialXCore.wasm`, `JsMaterialXCore.js`, `Js
 JavaScript unit tests are located in the `MaterialXTest` folder and use the `.spec.js` suffix. A sample browser is located in the `MaterialXView` folder which allows preview of some of provided sample MaterialX materials.
 
 ### Unit Tests 
-These tests require `node.js`, which is shipped with the emscripten environment. Make sure to `source` the `emsdk/emsdk_env.sh` script before running the steps described below, if you don't have NodeJs installed on your system already (running the command is not required otherwise).
+These tests require `node.js`, which is shipped with the emscripten environment. Make sure to `source` the `emsdk/emsdk_env.sh` script before running the steps described below, if you don't have NodeJs installed on your system already (running the command is not required otherwise). 
 
 1. From the `MaterialXTest` directory, install the npm packages.
     ```sh

javascript/build_javascript_win.bat

@@ -5,8 +5,8 @@
 @rem Edit the following paths to match your local locations for the Emscripten and MaterialX projects.
 set EMSDK_LOCATION=C:/GitHub/emsdk
 set MATERIALX_LOCATION=C:/GitHub/MaterialX
-call %EMSDK_LOCATION%/emsdk.bat install latest
-call %EMSDK_LOCATION%/emsdk.bat activate latest
+call %EMSDK_LOCATION%/emsdk.bat install 2.0.20
+call %EMSDK_LOCATION%/emsdk.bat activate 2.0.20
 if NOT ["%errorlevel%"]==["0"] pause
 @echo --------------------- Build MaterialX With JavaScript ---------------------
 @echo on