iSeg: Interactive 3D Segmentation via Interactive Attention

Itai Lang, Fei Xu, Dale Decatur, Sudarshan Babu, Rana Hanocka

University of Chicago

Abstract

We present iSeg, a new interactive technique for segmenting 3D shapes. Previous works have focused mainly on leveraging pre-trained 2D foundation models for 3D segmentation based on text. However, text may be insufficient for accurately describing fine-grained spatial segmentations. Moreover, achieving a consistent 3D segmentation using a 2D model is challenging since occluded areas of the same semantic region may not be visible together from any 2D view. Thus, we design a segmentation method conditioned on fine user clicks, which operates entirely in 3D. Our system accepts user clicks directly on the shape's surface, indicating the inclusion or exclusion of regions from the desired shape partition. To accommodate various click settings, we propose a novel interactive attention module capable of processing different numbers and types of clicks, enabling the training of a single unified interactive segmentation model. We apply iSeg to a myriad of shapes from different domains, demonstrating its versatility and faithfulness to the user's specifications.

Installation

Clone this repository:

git clone https://github.com/threedle/iSeg.git
cd iSeg/

Create and activate a conda environment:

conda create -n iseg python=3.9.18 --yes
conda activate iseg

Install the required packages:

sh ./install_environment.sh

Note: the installation assumes a machine with GPU and CUDA.

Demo

This demo shows how to run a pre-trained iSeg model for interactive segmentation of a hammer mesh.

Downlod the demo data:

bash download_demo_data.sh

• The hammer mesh will be stored at ./meshes/hammer.obj.

• The pre-trained vertex features will be stored at ./demo/hammer/encoder/pred_f.pth.

• The pre-trained decoder model will be stored at ./demo/hammer/decoder/decoder_checkpoint.pth.

If you experience issues with the script, download directly the mesh, features, and checkpoint, and store them under the corresponding folders.

Run the decoder with a single click on vertex 5141:

python decoder.py --mode test --save_dir ./demo/hammer/decoder/ --model_name decoder_checkpoint.pth --encoder_f_path ./demo/hammer/encoder/pred_f.pth --obj_path ./meshes/hammer.obj --select_vertices 5141

Run the decoder with a first positive click on vertex 5141 and a second positive click on vertex 61:

python decoder.py --mode test --save_dir ./demo/hammer/decoder/ --model_name decoder_checkpoint.pth --encoder_f_path ./demo/hammer/encoder/pred_f.pth --obj_path ./meshes/hammer.obj --select_vertices 5141 61

Run the decoder with a first positive click on vertex 5141 and a second negative click on vertex 10795:

python decoder.py --mode test --save_dir ./demo/hammer/decoder/ --model_name decoder_checkpoint.pth --encoder_f_path ./demo/hammer/encoder/pred_f.pth --obj_path ./meshes/hammer.obj --select_vertices 5141 -10795

For each run, the per-vertex predicted probability (an npy file), a mesh colored according to the predicted probabilities (a ply file), and rendered views of the colored mesh and the clicked points (a png file) will be saved under the folder ./demo/hammer/decoder/.

Note that you can save the colored mesh with spheres at the clicked points' location by adding the argument --show_spheres 1 to the commands above.

Training Instructions

This section explains how to generate data and train the encoder and decoder of iSeg. These items will be exemplified for the hammer mesh.

Download the ViT-H SAM model (simply click on the link). Put the downloaded file sam_vit_h_4b8939.pth under the folder ./SAM_repo/model_checkpoints/.

Generate data for training the encoder:

python encoder.py --obj_path ./meshes/hammer.obj --name hammer --encoder_data_dir ./data/hammer/encoder_data --generate_random_views 1 --start_training 0 --test 0

The data will be saved under the folder ./data/hammer/encoder_data/.

Train the encoder:

python encoder.py --obj_path ./meshes/hammer.obj --name hammer --encoder_data_dir ./data/hammer/encoder_data --encoder_model_dir ./experiments/hammer/encoder --generate_random_views 0 --num_epochs 3 --start_training 1 --test 1

The predicted encoder features per mesh vertex will be saved to ./experiments/hammer/encoder/pred_f.pth. These features will be used during the decoder training.

Generate data for training the decoder (single click and couple of clicks):

python data_generation.py --name hammer --obj_path ./meshes/hammer.obj --decoder_data_dir ./data/hammer/decoder_data --single_click 1 --second_positive 1 --second_negative 1

If you want to generate only single click data, set the arguments --second_positive 0 and --second_negative 0.

The data will be saved under the folder ./data/hammer/decoder_data/.

Train the decoder:

python decoder.py --obj_path ./meshes/hammer.obj --encoder_f_path ./experiments/hammer/encoder/pred_f.pth --decoder_data_dir ./data/hammer/decoder_data --save_dir ./experiments/hammer/decoder/ --model_name decoder_checkpoint.pth --mode train --num_epochs 5 --use_positive_click 1 --use_negative_click 1

If you generated only single click data, set the arguments --use_positive_click 0 and --use_negative_click 0.

The decoder model will be saved to ./experiments/hammer/decoder/decoder/decoder_checkpoint.pth

To evaluate the trained decoder, see the instuctions in the Demo section.

Citation

If you find iSeg useful for your work, please consider citing:

@article{lang2024iseg,
    author  = {Lang, Itai and Xu, Fei and Decatur, Dale and Babu, Sudarshan and Hanocka, Rana},
    title   = {{iSeg: Interactive 3D Segmentation via Interactive Attention}},
    journal = {arXiv preprint arXiv:2404.03219},
    year    = {2024}
}