[CVPR 2023 Highlight]

ESLAM: Efficient Dense SLAM System Based on Hybrid Representation of Signed Distance Fields

Project Page | Paper

Installation

First you have to make sure that you have all dependencies in place. The simplest way to do so, is to use anaconda.

You can create an anaconda environment called eslam. For linux, you need to install libopenexr-dev before creating the environment.

sudo apt-get install libopenexr-dev
    
conda env create -f environment.yaml
conda activate eslam

If desired, the Open3D package can be installed in the headless rendering mode. This is useful for running ESLAM on a server without a display. We recommend to install from this commit as we observed bugs in other releases of Open3D.

Run

Replica

Download the data as below and the data is saved into the ./Datasets/Replica folder.

bash scripts/download_replica.sh

and you can run ESLAM:

python -W ignore run.py configs/Replica/room0.yaml

The mesh for evaluation is saved as $OUTPUT_FOLDER/mesh/final_mesh_eval_rec_culled.ply, where the unseen and occluded regions are culled using all frames.

ScanNet

Please follow the data downloading procedure on ScanNet website, and extract color/depth frames from the .sens file using this code.

[Directory structure of ScanNet (click to expand)]

DATAROOT is ./Datasets by default. If a sequence (sceneXXXX_XX) is stored in other places, please change the input_folder path in the config file or in the command line.

  DATAROOT
  └── scannet
      └── scans
          └── scene0000_00
              └── frames
                  ├── color
                  │   ├── 0.jpg
                  │   ├── 1.jpg
                  │   ├── ...
                  │   └── ...
                  ├── depth
                  │   ├── 0.png
                  │   ├── 1.png
                  │   ├── ...
                  │   └── ...
                  ├── intrinsic
                  └── pose
                      ├── 0.txt
                      ├── 1.txt
                      ├── ...
                      └── ...

Once the data is downloaded and set up properly, you can run ESLAM:

python -W ignore run.py configs/ScanNet/scene0000.yaml

The final mesh is saved as $OUTPUT_FOLDER/mesh/final_mesh_culled.ply.

TUM RGB-D

Download the data as below and the data is saved into the ./Datasets/TUM folder.

bash scripts/download_tum.sh

and you can run ESLAM:

python -W ignore run.py configs/TUM_RGBD/freiburg1_desk.yaml

The final mesh is saved as $OUTPUT_FOLDER/mesh/final_mesh_culled.ply.

Evaluation

Average Trajectory Error

To evaluate the average trajectory error. Run the command below with the corresponding config file:

# An example for room0 of Replica
python src/tools/eval_ate.py configs/Replica/room0.yaml

Reconstruction Error

To evaluate the reconstruction error, first download the ground truth Replica meshes and the files that determine the unseen regions.

bash scripts/download_replica_mesh.sh

Then run the cull_mesh.py with the following commands to exclude the unseen and occluded regions from evaluation.

# An example for room0 of Replica
# this code should create a culled mesh named 'room0_culled.ply'
GT_MESH=cull_replica_mesh/room0.ply
python src/tools/cull_mesh.py configs/Replica/room0.yaml --input_mesh $GT_MESH

Then run the command below. The 2D metric requires rendering of 1000 depth images, which will take some time. Use -2d to enable 2D metric. Use -3d to enable 3D metric.

# An example for room0 of Replica
OUTPUT_FOLDER=output/Replica/room0
GT_MESH=cull_replica_mesh/room0_culled.ply
python src/tools/eval_recon.py --rec_mesh $OUTPUT_FOLDER/mesh/final_mesh_eval_rec_culled.ply --gt_mesh $GT_MESH -2d -3d

Visualizing ESLAM Results

For visualizing the results, we recommend to set mesh_freq: 40 in configs/ESLAM.yaml and run ESLAM from scratch.

After ESLAM is trained, run the following command for visualization.

python visualizer.py configs/Replica/room0.yaml --output output/Replica/room0 --top_view --save_rendering

The result of the visualization will be saved at output/Replica/room0/vis.mp4. The green trajectory indicates the ground truth trajectory, and the red one is the trajectory of ESLAM.

Note: mesh_freq: 40 means extracting a mesh every 40 input frames. Since extracting a mesh with a high resolution takes some time, for faster running of ESLAM for visualization set meshing resolution in configs/Replica/replica.yaml to a higher value before running ESLAM (e.g., 5 cm).

Visualizer Command line arguments

• --output $OUTPUT_FOLDER output folder (overwrite the output folder in the config file)
• --top_view set the camera to top view. Otherwise, the camera is set to the first frame of the sequence
• --save_rendering save rendering video to vis.mp4 in the output folder
• --no_gt_traj do not show ground truth trajectory

Related Repositories

We would like to extend our gratitude to the authors of NICE-SLAM for their exceptional work. Their code served as a valuable foundation for our own project, and we are appreciative of the effort they put into their work.

Contact

You can contact the author through email: mohammad.johari At idiap.ch.

Citing

If you find our work useful, please consider citing:

@inproceedings{johari-et-al-2023,
  author = {Johari, M. M. and Carta, C. and Fleuret, F.},
  title = {{ESLAM}: Efficient Dense SLAM System Based on Hybrid Representation of Signed Distance Fields},
  booktitle = {Proceedings of the IEEE international conference on Computer Vision and Pattern Recognition (CVPR)},
  year = {2023},
  type = {Highlight}
}

Acknowledgement

This work was supported by ams OSRAM.