Try to patch graph editor for headless.

Author: kwokcb

source/MaterialXGraphEditor/Main.cpp

@@ -167,6 +167,12 @@ int main(int argc, char* const argv[])
     glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0);
 #endif
 
+    // For headless operation (when captureFilename is specified), make window invisible
+    if (!captureFilename.empty())
+    {
+        glfwWindowHint(GLFW_VISIBLE, GL_FALSE);
+    }
+
     // Create window with graphics context
     GLFWwindow* window = glfwCreateWindow(1280, 960, "MaterialX Graph Editor", NULL, NULL);
     if (!window)