Adds DiffusionUNet3D and its modules to physicsnemo.experimental

CHANGELOG.md

@@ -111,6 +111,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   end-to-end training and sampling of epsilon-parameterized models.
   Losses gain an `epsilon_to_x0_fn` kwarg used for the epsilon-to-x0
   conversion required during DSM training.
+- Adds `DiffusionUNet3D` 3D U-Net diffusion backbone for volumetric data at
+  `physicsnemo.experimental.models.diffusion_unets`. Implements the
+  `DiffusionModel` protocol. Exposes reusable 3D building blocks
+  (`Conv3D`, `GroupNorm3D`, `UNetAttention3D`, `UNetBlock3D`) at
+  `physicsnemo.experimental.nn`.
 - Added support for Batched radius search, which enables Domino
   and GeoTransolver with local features and batch size > 1.
 - Added the underfill recipe.

physicsnemo/experimental/models/diffusion_unets/__init__.py

@@ -0,0 +1,19 @@
+# SPDX-FileCopyrightText: Copyright (c) 2023 - 2026 NVIDIA CORPORATION & AFFILIATES.
+# SPDX-FileCopyrightText: All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from .diffusion_unet_3d import DiffusionUNet3D
+
+__all__ = ["DiffusionUNet3D"]