campd 0.1.0

Framework for training context-aware diffusion models on trajectory data

Context-Aware Motion Planning Diffusion

A modular framework for training, and running inference with context-aware diffusion models on trajectory data. It provides a registry-driven component system, YAML-based configuration, and built-in support for HuggingFace Accelerate (multi-GPU), CUDA graphs, Weights & Biases logging, and experiment sweeps.

This framework accompanies the paper:

Accelerated Multi-Modal Motion Planning Using Context-Conditioned Diffusion Models Edward Sandra, Lander Vanroye, Dries Dirckx, Ruben Cartuyvels, Jan Swevers, Wilm Decré arXiv:2510.14615 — https://arxiv.org/abs/2510.14615

If you use this framework in your research, please cite:

@misc{sandra2025campd,
  title   = {Accelerated Multi-Modal Motion Planning Using Context-Conditioned Diffusion Models},
  author  = {Sandra, Edward and Vanroye, Lander and Dirckx, Dries and Cartuyvels, Ruben and Swevers, Jan and Decr\'{e}, Wilm},
  year    = {2025},
  eprint  = {2510.14615},
  archivePrefix = {arXiv},
  primaryClass  = {cs.RO},
  url     = {https://arxiv.org/abs/2510.14615},
}

---

API Documentation

Full API documentation for the project's codebase, including all registries, architectures, and experiments, is available at the CAMPD API Docs.

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Table of Contents

• Overview
• Installation
• Training Data
• Core Concepts
  • Registry System
  • The Spec Pattern
  • Configuration & Attribute Propagation
  • Dependencies / Imports in YAML
• Launching Experiments
  • Via campd-run (recommended)
  • Via custom Python script
• YAML Configuration Reference
• Extending the Framework
• Built-in Components
• Troubleshooting

---

Overview

CAMPD is built around a diffusion-model pipeline for trajectory generation conditioned on (but not limited to) environment context (e.g. obstacle geometries). The high-level flow is:

1. Data — Load trajectory datasets from HDF5 files (with context fields like cuboid/cylinder/sphere obstacle descriptions).
2. Model — A ContextTrajectoryDiffusionModel wrapping HuggingFace Diffusers schedulers, a reverse-diffusion denoising network (e.g. TemporalUnet), and an optional context encoder.
3. Training — A Trainer runs the training loop with configurable objectives, callbacks, summaries, multi-objective optimization (TorchJD), AMP, gradient clipping, and optional CUDA graph acceleration.
4. Inference — Load a trained checkpoint and sample trajectories, optionally validating them with domain-specific validators.

Everything is wired together through YAML config files and a registry system, so you can swap components without changing code.

---

Installation

Prerequisites

• Python ≥ 3.10
• CUDA-capable GPU (recommended)

Steps

pip install git+https://github.com/meco-group/campd.git@v0.1.0

This installs the campd package and the campd-run CLI entry point.

Note: Some example projects (e.g. examples/franka_curobo/) may have additional dependencies not listed in pyproject.toml (e.g. curobo, pinocchio). These are installed separately; check each example's requirements.txt.

Note: If you want to enable Weights and Biases logging, install it with pip install wandb and run wandb login to authenticate.

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Training Data

Training datasets for the sphere-based and MPINets environments are stored as Git LFS objects in a separate repository. Download and extract them before running the example experiments:

GIT_LFS_SKIP_SMUDGE=1 git clone https://github.com/meco-group/campd-data.git /tmp/campd-data
(cd /tmp/campd-data && git lfs pull)
mkdir -p data/train/
tar -xzf /tmp/campd-data/train_data_campd_franka_spheres.tar.gz -C data/train/
tar -xzf /tmp/campd-data/train_data_campd_mpinets.tar.gz        -C data/train/
rm -rf /tmp/campd-data

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Core Concepts

Registry System

The framework uses a registry pattern to enable config-driven component selection. Each category of component has its own Registry instance:

Registry	Module	Purpose
EXPERIMENTS	experiments/registry.py	Experiment types
MODULES	architectures/registry.py	Generic nn.Module building blocks
REVERSE_NETS	architectures/registry.py	Denoising networks
CONTEXT_NETS	architectures/registry.py	Context encoder networks
LOSSES	training/registry.py	Loss functions
CALLBACKS	training/registry.py	Training callbacks
SUMMARIES	training/registry.py	Training summaries
OBJECTIVES	training/registry.py	Training objectives
VALIDATORS	experiments/validators.py	Inference validators

Components self-register using a decorator:

from campd.training.registry import CALLBACKS

@CALLBACKS.register("MyCallback")
class MyCallback(Callback):
    ...

Then in the YAML config:

callbacks:
  - cls: "MyCallback"

Critical: For a component to be available at runtime, its module must be imported before the registry lookup happens. This is handled by two mechanisms:

1. campd/all_imports.py — Bulk-imports all built-in subpackages (architectures, data, experiments, models, training), which triggers their __init__.py chains and populates the registries with built-in components.
2. The dependencies key in YAML config — Imports external/example-specific modules at startup (see Dependencies / Imports in YAML).

The Spec Pattern

Spec (defined in utils/registry.py) is a Pydantic model that describes how to build an object from config. It supports two modes:

Init Mode — Direct constructor kwargs

optimizer:
  cls: "torch.optim.Adam"      # Full import path or registry key
  init:
    lr: 1.0e-4
    weight_decay: 0.0

This calls torch.optim.Adam(lr=1e-4, weight_decay=0.0).

Config Mode — Factory method via from_config

objective:
  cls: "DiffusionObjective"    # Registry key
  config:
    loss_fn:
      cls: "torch.nn.MSELoss"
      init:
        reduction: "mean"

This calls DiffusionObjective.from_config(config_dict). The class must have a from_config classmethod.

Registry vs Import Path Resolution

• If a registry field is set on the Spec, the cls string is looked up in that specific registry.
• Otherwise, the cls string is first tried as a registry key (if a registry is passed to build_from), then as a Python import path (e.g. torch.optim.Adam).
• This means you can reference any importable class by its full dotted path, or use short registry keys for registered components.

Configuration & Attribute Propagation

The framework uses Pydantic models for configuration validation. A key feature is attribute propagation: parent-level config values are automatically pushed down to nested child configs that share the same field name. For example:

experiment:
  device: "cuda:0"           # Parent-level
  dataset:
    # device is NOT declared here, but if TrajectoryDatasetCfg has a
    # 'device' field, it will receive "cuda:0" from the parent.
    ...
  trainer:
    tensor_args:
      device: "cuda:0"       # Explicit — but could also be propagated

YAML anchors (&name / *name) can be used in config files for DRY configuration.

Dependencies / Imports in YAML

The dependencies top-level key in YAML configs lists modules or directories that should be imported before the experiment runs. This is essential for registering custom components (e.g. example-specific summaries, validators, architectures):

dependencies:
  - "../src"              # A directory — all .py files inside are imported
  - "my_custom_module"    # A Python module import path
  - "./my_file.py"        # A single Python file

Paths are resolved relative to the config file's directory.

This is the mechanism that makes custom components available to the registries. If you define a custom @SUMMARIES.register("ValidationSummary") class in examples/franka_curobo/src/training_summary.py, listing "../src" in dependencies ensures it's imported and registered before the config tries to reference "ValidationSummary".

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Launching Experiments

Via campd-run (recommended)

The campd-run CLI is installed as a console script by pip:

campd-run path/to/config.yaml

This:

1. Parses the YAML file.
2. Extracts dependencies, experiment, wandb, launcher, and sweep sections.
3. Imports built-in and user-defined dependencies to populate registries.
4. Uses experiment-launcher to manage experiment execution (seeding, output directories, optional SLURM submission).
5. Looks up the experiment class via experiment.cls in the EXPERIMENTS registry and calls its run() method.

Launcher configuration controls experiment management:

launcher:
  exp_name: "my_experiment"
  n_seeds: 1                  # Number of seeds (repetitions)
  start_seed: 0
  base_dir: "results/"        # Output base directory
  use_timestamp: true         # Append timestamp to output dir
  resources: 
    n_exps_in_parallel: 1       # Parallel experiments
    ... (see experiment-launcher docs)

Via custom Python script

For simpler use cases or debugging, you can bypass the launcher:

import os
from campd.experiments import TrainExperiment

base_dir = os.path.dirname(os.path.abspath(__file__))
exp = TrainExperiment.from_yaml(os.path.join(base_dir, "configs/train.yaml"))
exp.run()

Note: When using from_yaml, the dependencies section is not processed automatically. You must import your custom modules manually before calling from_yaml (e.g. import my_custom_module).

The campd-run CLI handles this for you.

---

YAML Configuration Reference

A full config file has up to five top-level sections:

# 1. Dependencies — modules/directories to import for custom registrations
dependencies:
  - "../src"

# 2. WandB — Weights & Biases logging
wandb:
  mode: "online"           # "online", "offline", or "disabled"
  entity: "my-team"
  project: "my-project"
  group: "group_name"
  name: &name "run_name"
  

# 3. Launcher — experiment-launcher settings
launcher:
  exp_name: *name
  base_dir: "results/"
  n_seeds: 1
  # ... (see experiment-launcher docs)

# 4. Sweep — hyperparameter sweep (optional)
sweep:
  trainer:
    lr: [1e-4, 1e-3]      # Creates one run per value

# 5. Experiment — the actual experiment configuration
experiment:
  cls: "train"             # Registered experiment key

  # Common fields (from ExperimentCfg):
  seed: 42
  device: "cuda:0"
  # results_dir: set by launcher

  # Experiment-specific fields (e.g. TrainExperimentCfg):
  dataset_dir: "data/train/my_dataset"
  train_file: "train.hdf5"
  val_file: "val.hdf5"    # Optional
  # val_set_size: 0.1       # Optional

  dataset:
    trajectory_state: "pos"          # "pos", "pos+vel", "pos+vel+acc"
    field_config:
      trajectory_field: "solutions"  # HDF5 key for trajectory data
      q_dim: 7                       # Configuration-space dimension
      context_fields:                # Maps list of HDF5 keys -> context key
        cuboids: ["cuboid_centers", "cuboid_dims", "cuboid_quaternions"]
        # Note that the subkeys are still accessible inside the TrajectoryContext
        # object
      # also possible to use a list of HDF5 keys
      # context_fields:
      #   - "cuboid_centers"
      #   - "cuboid_dims"
      #   - "cuboid_quaternions"
    # ...

  model:
    state_dim: 7
    model_type: "epsilon"            # "epsilon", "sample", or "v_prediction"
    n_diffusion_steps: 25
    network:                         # Spec for reverse diffusion network
      cls: "TemporalUnet"
      config: { ... }
    context_network:                 # Spec for context encoder (optional)
      cls: "campd.architectures.context.encoder.ContextEncoder"
      config: { ... }

  trainer:
    max_epochs: 200
    optimizer:
      cls: "torch.optim.Adam"
      init: { lr: 1e-4 }
    objective:
      cls: "DiffusionObjective"
      config:
        loss_fn:
          cls: "torch.nn.MSELoss"
          init: { reduction: "mean" }
    callbacks:
      - cls: "PrinterCallback"
      - cls: "EMACallback"
        init: { decay: 0.995 }
      - cls: "CheckpointCallback"
        init: { save_best: true }
      - cls: "WandBCallback"
    summaries:
      - cls: "ValidationSummary"      # Custom (from dependencies)
        init: { every_n_steps: 2500 }

---

Extending the Framework

The general pattern for adding a new component:

1. Create a Python file with your class, inheriting from the appropriate base class.
2. Decorate it with @REGISTRY.register("key") using the relevant registry.
3. Make sure it's imported at startup — either by placing it in a built-in subpackage (and re-exporting via __init__.py), or by listing its module/directory in the dependencies section of your YAML config.
4. Reference it in your YAML config via the registry key.

Registering a New Experiment

# my_experiments/custom_exp.py
from campd.experiments.base import BaseExperiment, ExperimentCfg
from campd.experiments.registry import EXPERIMENTS
from pydantic import validate_call

class MyExperimentCfg(ExperimentCfg):
    my_param: str = "default"

@EXPERIMENTS.register("my_experiment")
class MyExperiment(BaseExperiment):
    CfgClass = MyExperimentCfg

    @validate_call
    def __init__(self, cfg: MyExperimentCfg):
        super().__init__(cfg)

    def run(self):
        print(f"Running with param: {self.cfg.my_param}")

dependencies:
  - "my_experiments"        # Directory containing custom_exp.py

experiment:
  cls: "my_experiment"
  my_param: "hello"

Registering a New Network Architecture

# my_networks/custom_net.py
import torch.nn as nn
from campd.architectures.registry import REVERSE_NETS
from campd.utils.registry import FromCfg

@REVERSE_NETS.register("MyDenoiser")
class MyDenoiser(nn.Module):
    def __init__(self, state_dim: int, hidden_dim: int):
        super().__init__()
        # ... build layers ...

    @classmethod
    def from_config(cls, cfg):
        if isinstance(cfg, dict):
            return cls(**cfg)
        return cls(**cfg.model_dump())

    def forward(self, x, t, context=None):
        # x: [B, T, state_dim], t: [B], context: EmbeddedContext or None
        ...

model:
  network:
    cls: "MyDenoiser"
    config:
      state_dim: 7
      hidden_dim: 128

Registering a New Training Callback

from campd.training.callbacks import Callback
from campd.training.registry import CALLBACKS

@CALLBACKS.register("LRLoggerCallback")
class LRLoggerCallback(Callback):
    def on_epoch_end(self, trainer, train_losses=None):
        lr = trainer.optimizer.param_groups[0]['lr']
        print(f"Current LR: {lr}")

Available hooks: on_train_start, on_fit_start, on_train_end, on_epoch_start, on_epoch_end, on_batch_start, on_batch_end, on_validation_start, on_validation_end, on_summary_end.

Registering a New Training Summary

from campd.training.summary import Summary
from campd.training.registry import SUMMARIES

@SUMMARIES.register("MySummary")
class MySummary(Summary):
    def __init__(self, every_n_steps=1000):
        super().__init__(every_n_steps=every_n_steps)

    def _run(self, model, train_dataloader, val_dataloader, step):
        # Generate samples, compute metrics, return dict/figures
        return {"my_metric": 0.95}

Registering a New Training Objective

from campd.training.objectives.base import TrainingObjective
from campd.training.registry import OBJECTIVES

@OBJECTIVES.register("MyObjective")
class MyObjective(TrainingObjective):
    @classmethod
    def from_config(cls, cfg):
        return cls(cfg)

    def step(self, model, batch):
        # Return: (losses_dict, model_output, info_dict)
        loss = ...
        return {"my_loss": loss}, model_out, {}

Registering a New Validator

from campd.experiments.validators import Validator, VALIDATORS

@VALIDATORS.register("MyValidator")
class MyValidator(Validator):
    def validate(self, batch, output_dir):
        # Return dict of validation metrics
        return {"success_rate": 0.85}

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Built-in Components

Experiments

Key	Class	Description
"train"	TrainExperiment	Full training pipeline (data → model → fit)
"inference"	InferenceExperiment	Load checkpoint & sample trajectories

Callbacks

Key	Description
"PrinterCallback"	Logs training start/end messages
"EMACallback"	Exponential moving average of model weights
"CheckpointCallback"	Saves checkpoints (best, last, periodic)
"WandBCallback"	Logs metrics/artifacts to Weights & Biases
"EarlyStoppingCallback"	Stops training when validation loss plateaus

Objectives

Key	Description
"DiffusionObjective"	Standard diffusion loss (ε, sample, or v)

Losses

Key	Description
"WeightedL1"	Weighted L1 loss
"WeightedL2"	Weighted L2 loss
"MSE"	nn.MSELoss
"L1"	nn.L1Loss

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Troubleshooting

• CUDA graph errors: If use_cuda_graph: true and you get runtime errors, ensure your PyTorch CUDA version matches the system CUDA version. Also verify that all tensor shapes remain constant across batches (CUDA graphs require fixed shapes).

• KeyError: Unknown 'X' in registry 'Y': The component X is not registered. Ensure:

  1. The module defining the component is imported before the registry lookup.
  2. The module is listed in the dependencies section of your config.
  3. The @REGISTRY.register("X") decorator is present on the class.

If your issue isn't covered above, please open a GitHub issue with a minimal reproducible example and the full error traceback.

License

See LICENSE for details.