ForestMamba

ForestMamba is a forest tree instance segmentation model built on a sparse Mamba (SSM) backbone with CHM-guided multi-scale query initialisation.

• 🎉 [2026-08] ForestMamba has been accepted to the 37th British Machine Vision Conference (BMVC 2026)!
• 🌲 [2026-08] ForestMamba has been integrated into the 3Dtrees.earth platform.
• 📄 Paper on arXiv
• 📦 Dataset on Zenodo
• 🔗 Pre-trained ForestMamba checkpoint (Google Drive)
• 🚀 The released pre-trained checkpoint outperforms the results reported in the paper. This checkpoint was trained with synchronized BatchNorm (SyncBatchNorm) across GPUs, whereas the paper results used standard BatchNorm.

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Directory structure

Download the dataset and pre-trained checkpoint from Zenodo or Google Drive and place them as follows:

ForestMamba/
├── configs/ForAINetv2/
│   └── forestmamba_chm_radius16_qp300_2many_v6.py   ← inference config
├── data/
│   └── ForAINetV2/
│       ├── train_val_data/
│       └── test_data/
├── work_dirs/
│   └── forestmamba/
│       └── v6_epoch_1500_fix.pth                    ← pre-trained checkpoint

---

Environment setup

1. Build Docker image

cd /path/to/ForestMamba

sudo docker build -t forestmamba-image .

sudo docker run --gpus all --shm-size=128g -d -p 127.0.0.1:49211:22 \
  -v /path/to/ForestMamba:/workspace \
  -v /workspace/segmentator:/workspace/segmentator \
  --name forestmamba-container forestmamba-image

sudo docker exec -it forestmamba-container /bin/bash

2. Install Mamba-specific packages

ForestMamba requires the following packages:

pip install mamba-ssm==1.1.1
pip install causal-conv1d==1.1.1
pip install hilbertcurve==2.0.5
pip install transformers==4.36.0
pip install importlib-metadata==4.13.0
pip install wandb

3. Resolve common import errors

# Test torch-points-kernels
python -c "from torch_points_kernels import instance_iou; print('torch-points-kernels loaded successfully')"

# If you see: ModuleNotFoundError: No module named 'torch_points_kernels.points_cuda'
pip uninstall torch-points-kernels -y
pip install --no-deps --no-cache-dir torch-points-kernels==0.7.0

# Reinstall torch-cluster
pip uninstall torch-cluster -y
pip install torch-cluster --no-cache-dir --no-deps

4. Replace required mmengine/mmdet3d files

pip show mmengine   # check the install path

cp replace_mmdetection_files/loops.py \
   /opt/conda/lib/python3.10/site-packages/mmengine/runner/
cp replace_mmdetection_files/base_model.py \
   /opt/conda/lib/python3.10/site-packages/mmengine/model/base_model/
cp replace_mmdetection_files/transforms_3d.py \
   /opt/conda/lib/python3.10/site-packages/mmdet3d/datasets/transforms/
cp replace_mmdetection_files/distributed.py \
   /opt/conda/lib/python3.10/site-packages/mmengine/model/wrappers/distributed.py

---

Data preparation

Before running anything, update data_root_forainetv2 in the config to point to your data directory:

# configs/ForAINetv2/forestmamba_chm_radius16_qp300_2many_v6.py
data_root_forainetv2 = '/your/path/to/ForAINetV2/'

export PYTHONPATH=/workspace/ForestMamba

# Place .ply files:
#   training / validation → /workspace/data/ForAINetV2/train_val_data/
#   test                  → /workspace/data/ForAINetV2/test_data/

pip install laspy "laspy[lazrs]"

# Preprocess raw point clouds
cd /workspace/data/ForAINetV2
python batch_load_ForAINetV2_data.py --num_workers 8
# → produces /workspace/data/ForAINetV2/forainetv2_instance_data/

# Create .pkl info files
cd /workspace
python tools/create_data_forainetv2.py forainetv2

---

Training

Multi-GPU (recommended):

export PYTHONPATH=/workspace/ForestMamba
export NCCL_SOCKET_IFNAME=lo
export NCCL_IB_DISABLE=1
export NCCL_P2P_DISABLE=1

CUDA_VISIBLE_DEVICES=0,1 PORT=29500 bash tools/dist_train.sh \
  configs/ForAINetv2/forestmamba_chm_radius16_qp300_2many_v6.py \
  2 \
  --work-dir work_dirs/forestmamba

Single GPU:

export PYTHONPATH=/workspace/ForestMamba

CUDA_VISIBLE_DEVICES=0 python tools/train.py \
  configs/ForAINetv2/forestmamba_chm_radius16_qp300_2many_v6.py \
  --work-dir work_dirs/forestmamba

Resume from a checkpoint:

CUDA_VISIBLE_DEVICES=0,1 PORT=29500 bash tools/dist_train.sh \
  configs/ForAINetv2/forestmamba_chm_radius16_qp300_2many_v6.py \
  2 \
  --work-dir work_dirs/forestmamba \
  --resume work_dirs/forestmamba/epoch_1000.pth

---

Inference

The pre-trained checkpoint from Google Drive / Zenodo is already fixed and ready to use directly.

If you trained your own model, fix the checkpoint first:

python tools/fix_spconv_checkpoint.py \
  --in-path  work_dirs/forestmamba/v6_epoch_1500.pth \
  --out-path work_dirs/forestmamba/v6_epoch_1500_fix.pth

Run inference

To disable Weights & Biases logging during inference:

export WANDB_MODE=disabled

Single GPU:

export PYTHONPATH=/workspace/ForestMamba

CUDA_VISIBLE_DEVICES=0 python tools/test.py \
  configs/ForAINetv2/forestmamba_chm_radius16_qp300_2many_v6.py \
  work_dirs/forestmamba/v6_epoch_1500_fix.pth

Multi-GPU:

export PYTHONPATH=/workspace/ForestMamba

CUDA_VISIBLE_DEVICES=0,1,2,3 torchrun \
  --nproc_per_node=4 \
  --master_port=29500 \
  tools/test.py \
  configs/ForAINetv2/forestmamba_chm_radius16_qp300_2many_v6.py \
  work_dirs/forestmamba/v6_epoch_1500_fix.pth \
  --launcher pytorch

---

Evaluation

python tools/eval_predictions.py \
  work_dirs/inference/forestmamba \
  --workers 16

---

Testing on custom data

1. Place your test files

/workspace/data/ForAINetV2/test_data/

2. Update the test list

Edit /workspace/data/ForAINetV2/meta_data/test_list.txt and append your file names (without extension).

3. Re-run preprocessing and inference

cd /workspace/data/ForAINetV2
python batch_load_ForAINetV2_data.py --num_workers 8
cd /workspace
python tools/create_data_forainetv2.py forainetv2

# Then run inference as above

---

Two-pass inference for dense forests

In very dense plots some trees may be missed in a single pass. A second pass on the remaining unsegmented points improves recall:

bash /workspace/tools/inference_bluepoint.sh

Before running, update BLUEPOINTS_DIR in the script to match your output directory, and switch the save mode in oneformer3d/oneformer3d.py inside the predict function of ForAINetV2OneFormer3D_XAwarequery:

# self.save_ply_withscore(...)
self.save_bluepoints(...)

And set:

is_test = True
if is_test:

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Non-.ply input files

If your test data is not in .ply format (e.g., .laz):

1. Edit data/ForAINetV2/batch_load_ForAINetV2_data.py — update the file path in export_one_scan().
2. Edit data/ForAINetV2/load_forainetv2_data.py — replace the read_ply() call with your loader.
3. If your files have no ground-truth labels, replace the label loading lines with dummy arrays:

semantic_seg = np.ones((points.shape[0],), dtype=np.int64)
treeID = np.zeros((points.shape[0],), dtype=np.int64)

Recommendation: Converting to .ply beforehand is the simplest option.

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Memory / OOM tips

• For GPUs with less memory, reduce radius in the config.
• For inference OOM, lower chunk in the config or reduce num_points in oneformer3d/oneformer3d.py.

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Optional tips

Tensorboard:

tensorboard --logdir=work_dirs/forestmamba/vis_data/ --host=0.0.0.0 --port=6006

SSH debugging in VS Code:

apt-get install -y openssh-server
service ssh start
passwd root
echo -e "PermitRootLogin yes\nPasswordAuthentication yes" >> /etc/ssh/sshd_config
service ssh restart

Forward port 22 with -p 127.0.0.1:49211:22 in your docker run command.

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License

ForestMamba is built on the ForestFormer3D codebase, which is based on OneFormer3D by Danila Rukhovich (https://github.com/filaPro/oneformer3d), licensed under CC BY-NC 4.0. This repository is released under the same license.