Announcement: MDL SDK 2024.1.1 released

[mkroll]

Get the update on MDL SDK | NVIDIA Developer and GitHub - NVIDIA/MDL-SDK: NVIDIA Material Definition Language SDK (on branch release/2024.1).

MDL SDK 2024.1.1 (381500.4681): 31 Mar 2025

Added and Changed Features

• General

  • MDL Python Bindings:

    • Improve type hints for *_as(type, ...) functions.

  • On Windows, the MSVC runtime flavor is now controlled by the new options
    MDL_MSVC_DYNAMIC_RUNTIME and MDL_MSVC_DYNAMIC_RUNTIME_DXR_EXAMPLE. Support
    for the old option MDL_MSVC_DYNAMIC_RUNTIME_EXAMPLES has been removed.

  • The severity filter for log messages is now also applied to delayed
    messages, i.e., the first two messages concerning the location and version
    information of the library.

  • Added a new context option “handle_filename_conflicts” to control naming of
    resources during export. See IMdl_impexp_api::export_module() for details.

  • Improved performance of code generation by the MDL backends on Linux by 3-4%.

  • Added SECURITY.md file with instructions how to report security issues.

  • Added ::nvidia::distilling_support to the example content such that it can be
    used by the MDL Core examples.

  • Classified all plugins as cmake module libraries instead of shared
    libraries. This avoids that they get used incorrectly with
    target_link_libraries() and eliminates the .lib files on Windows.

  • Linking the MDL Core/SDK library is deprecated (this also happens implicitly
    when using target_link_libraries(). The cmake library type will be changed
    from SHARED to MODULE in a future release. Likewise, the corresponding
    import libraries on Windows will be removed. Users should access the MDL
    Core/SDK library using LoadLibrary()/GetProcAddress() or dlopen()/dlsym()
    instead (as it is done in all examples). Cmake users should use:

    get_target_property(SOME_VAR mdl::mdl_sdk INTERFACE_INCLUDE_DIRECTORIES)
target_include_directories(your_target PRIVATE ${SOME_VAR})

    (similarly for mdl::mdl_core).

  • Added the linker option --strip-all/-x for release builds on Linux/MacOS.

• MDL Compiler and Backends

  • The compiler now obeys the target_material_model annotation when used on material
    presets. This allows to make a target material from a preset, even if the original material
    is not. This implements user expectations.

• MDL SDK examples

  • Added new dependency_inspector example:
    • It lists all file dependencies of an MDL module for direct and (optionally) indirect
      imports and resources.
  • Example modules:
    • Completely refactored this example that now extends its functionality.
    • Added options to set MDL search paths and load/scan user selected modules.
    • Added filter option to select which information to output from a module: imports,
      types and constants definitions, function and material definitions, resources.
    • Added option to scan indirect dependencies and resources from imported modules.
    • Added option to display the default values, temporaries and body of selected function
      and material definitions.
  • Example DXR:
    • Updated MaterialX SDK to 1.39.3.
    • Added option to override selected materials in the scene:
      “--mat_selective <selector> <qualified_name>”.
    • Added option to control the camera exposure for matching certain render tests:
      “--cam_exposure”.
    • Added support for subsurface scattering by implementing the Henyey-Greenstein
      phase function.
    • Added option to control the subsurface scattering path length: “--max_sss_steps”.
  • Third-party dependencies:
    • Disabled XInput support in the ImGui compilation.

• MDL Core examples

  • Shared:
    • Added new Distiller_helper helper class. It simplifies the context creation and
      procedure required for distilling an MDL material using Core API.
  • Example code_gen:
    • Added option to distill an MDL material to a given material target model.

Fixed Bugs

• MDL 1.10 Language Specification

  • Fixed minor typographic errors and improved wording.

• General

  • Improved the handling of invalid re-use of names of DB elements eligible
    for garbage collection. As a consequence, some of these uses are considered
    safe now. See “Database Access” in the API reference documentation for
    details.
  • Fixed export of MDL modules with animated and/or uvtile textures if the
    texture file exists already. Now we generate a unique filename (as for
    plain textures and other resources) instead of unconditionally overwriting
    an existing file.

• MDL Compiler and Backends

  • Fixed entity resolver returns only a file name (without the directory) when resolving
    UDIM sets on disk.
  • Fixed wrong error message “index of declarative types must be uniform” that was issued
    by the compiler if the index of an declarative array access was a constant.
  • Fixed wrong error messages issued that a (constant) array cannot be converted into a
    uniform array.
  • Fixed missing backend support for implicit conversion between declarative structs of the
    same category in default argument, causing a crash when target code is generated.
  • Fixed missing type import causing assertions in debug build.
  • Added missing support for the hidden argument of the decl_cast intrinsic function.
  • Fixed several problems with the auto import of entities in MDL, most of them now visible
    by the user, but causing assertions in debug builds.
  • Fixed core compiler not recognizing several declarative properties, causing missing errors
    when declarative types are used inside non-declarative functions, especially in combination
    with declarative structs defined in the ::df module (bsdf_components and alikes).
  • Fixed pre-calculated arrays not being properly stored in texture results (HLSL/GLSL).
  • Fixed NaNs being generated by sqrt(+inf) for the native backend.
  • Fixed crash when compiling functions with derivative arrays as parameters.

• MDL SDK examples

  • Fixed memory leaks in MDL examples.
  • Fixed trace_shadow function executing a generated MDL function potentially requiring
    texture results without providing them.