active-3d-gym

Active3DGym is a set of benchmark environments for the active view planning problem in robotics.

Usage

git clone https://github.com/kevin-thankyou-lin/active-3d-gym
cd active-3d-gym
pip install -e .

Then, to use the provided environments in a specific file:

import gym
import active_3d

env = gym.make("OfflineActive3D-v0", data_dir=<path/to/data_dir>)

We assume data_dir's folder structure is as follows:

    data_dir/
        - transform_train.json
        - transform_val.json
        - object_bounds.json # mightn't be necessary: include object bound information?
        - images/
            im_0.png
            im_0_depth.exr
            im_0_distance.exr
            im_1.png
            im_1_depth.exr
            im_1_distance.exr
            ...

transform_train.json (and, optionally, transform_val.json) should have file structure compatible with nerf data, such as:

{
    "fl_x": ...,
    "fl_y": ...,
    "c_x": ...,
    "c_y": ...,
    "aabb_scale": null,
    "frames": [
        {
            "file_path": "train/im_0.png",
            "depth_path": "train/im_0_depth.exr",
            "distance_path": "train/im_0_distance.exr",
            "transform_matrix": [...]
        }, 
        ...
    ]

To generate your own offline dataset, follow the instructions detailed below at Generating offline data.

A note about the depth image data

If a pixel has an invalid depth values or if the depth value is infinity, the depth map (and distance map) value should be set to 0 as convention.

Helpful note from Blenderproc docs: "While distance and depth images sound similar, they are not the same: In distance images, each pixel contains the actual distance from the camera position to the corresponding point in the scene. In depth images, each pixel contains the distance between the camera and the plane parallel to the camera which the corresponding point lies on."

Generating offline data

1. Install blenderproc
2. Install dcargs via blenderproc pip install git+https://github.com/brentyi/dcargs.git
3. Install Shapenet
4. You can now run scripts/blenderproc_offline_data to generate offline data for the gym environment^^

blenderproc run scripts/blenderproc_offline_data.py view-planner.num-cam-positions <num cam positions> --shapenet-path <path/to/ShapenetCoreV2> --candidate-view-radius 0.8 --obj <object>

Example train / eval data generation script:

blenderproc run scripts/blenderproc_offline_data.py --shapenet-path ../ShapeNetCore.v2/ --view-planner.num-cam-positions 3 --save-data-type eval --convert-background-to-white --save-ray-info

--save-ray-info: saves rays for ray distance supervision (c.f. DS-NeRF)

--convert-background-to-white: converts (infinite distance) background to RGB color (255, 255, 255)

NOTE: dcargs replaces underscores with dashes on the command line, and supports nested args (e.g. view-planner.num-cam-positions)

The script found in blenderproc_offline_data.py creates a directory <offline gym data dir>/<save data type>/<shapenet object name>. The folder structure within this directory follows that of nerf, ie.

transforms_train.json
transforms_val.json
images/
    img_0.png
    img_1.png
    ...

These instructions have been tested extensively on Ubuntu 18.04.