Function configure_usd_plugins

src/app/main.cpp:141–179

Register OpenUSD plugin resources deployed beside the executable. On Windows: /usd/ — keeps relative LibraryPaths correct. On Linux: /../lib/usd/ — conventional layout. Must be called before any USD API usage (stage creation, schema lookup). The env-var approach (PXR_PLUGINPATH_NAME) does not work reliably on Windows because USD DLLs may initialise before main() runs.

    // The env-var approach (PXR_PLUGINPATH_NAME) does not work reliably on
    // Windows because USD DLLs may initialise before main() runs.
    void configure_usd_plugins() {
        std::filesystem::path exe_dir;
        try {
            exe_dir = lfs::core::getExecutableDir();
        } catch (...) {
            return;
        }

        std::error_code ec;

        // On Windows, plugins sit next to the exe at <exe_dir>/usd/ so that
        // relative LibraryPath entries (e.g. "../../usd_ar.dll") resolve to
        // the DLL copies that are already loaded by Windows at startup.
        // On Linux they follow the conventional <exe_dir>/../lib/usd/ layout.
#ifdef _WIN32
        auto usd_dir = exe_dir / "usd";
#else
        auto usd_dir = exe_dir / ".." / "lib" / "usd";
#endif
        usd_dir = std::filesystem::canonical(usd_dir, ec);
        if (ec || !std::filesystem::is_directory(usd_dir, ec)) {
            LOG_ERROR("[USD] plugin directory not found ({})",
                      ec ? ec.message() : "not a directory");
            return;
        }

        const std::string path_utf8 = lfs::core::path_to_utf8(usd_dir);

        // Also set the env var for any code that reads it directly.
#ifdef _WIN32
        _putenv_s("PXR_PLUGINPATH_NAME", path_utf8.c_str());
#else
        setenv("PXR_PLUGINPATH_NAME", path_utf8.c_str(), /*overwrite=*/0);
#endif

        // Programmatically register plugins so the Plug system finds them
        // regardless of compiled-in search paths or env var timing.
        pxr::PlugRegistry::GetInstance().RegisterPlugins(path_utf8);
    }
} // namespace

int main(int argc, char* argv[]) {