
LidarAugment: Searching for Scalable 3D LiDAR Data Augmentations
Zhaoqi Leng1∗, Guowang Li1, Chenxi Liu1, Ekin Dogus Cubuk2, Pei Sun1, Tong He1,
Dragomir Anguelov1and Mingxing Tan1
Abstract— Data augmentations are important in training
high-performance 3D object detectors for point clouds. Despite
recent efforts on designing new data augmentations, perhaps
surprisingly, most state-of-the-art 3D detectors only use a
few simple data augmentations. In particular, different from
2D image data augmentations, 3D data augmentations need
to account for different representations of input data and
require being customized for different models, which introduces
significant overhead. In this paper, we resort to a search-based
approach, and propose LidarAugment, a practical and effective
data augmentation strategy for 3D object detection. Unlike
previous approaches where all augmentation policies are tuned
in an exponentially large search space, we propose to factorize
and align the search space of each data augmentation, which
cuts down the 20+ hyperparameters to 2, and significantly
reduces the search complexity. We show LidarAugment can
be customized for different model architectures with different
input representations by a simple 2D grid search, and con-
sistently improve both convolution-based UPillars/StarNet/RSN
and transformer-based SWFormer. Furthermore, LidarAug-
ment mitigates overfitting and allows us to scale up 3D detectors
to much larger capacity. In particular, by combining with latest
3D detectors, our LidarAugment achieves a new state-of-the-art
74.8 mAPH L2 on Waymo Open Dataset.
I. INTRODUCTION
Data augmentations are widely used in training deep
neural networks. In particular, for autonomous driving, many
data augmentations are developed to improve data efficiency
and model generalization. However, most recent 3D object
detectors only use a few basic data augmentation operations
such as rotation, flip and ground-truth sampling [1], [2], [3],
[4], [5], [6], [7]. This is in a surprising contrast to 2D image
recognition and detection, where much more sophisticated
2D data augmentations are commonly used in modern image-
based models [8], [9], [10], [11], [12], [13]. In this paper,
we aim to answer: is it practical to adopt more advanced 3D
data augmentations to improve modern 3D object detectors,
especially for high-capacity models?
The main challenge of adopting advanced 3D data aug-
mentations is that 3D augmentations are often sensitive to
input representations and model capacity. For example, range
image based models and point cloud based models require
different types of data augmentation due to different input
representations. High capacity 3D detectors are typically
prone to overfitting and require stronger overall data augmen-
tation compared to lite models with fewer parameters. There-
fore, tailoring each 3D augmentation for different models is
necessary. However, the search space scales exponentially
with respect to the number of hyperparameters, which leads
1Waymo Research, 2Google Brain, ∗lengzhaoqi@waymo.com
UPillar UPillar-L
50
55
60
65
70
75
80
3D mAPH L2
57.8 60.0
63.7
71.0
Baseline LidarAugment
Fig. 1: Model scaling with LidarAugment on Waymo
Open Dataset. Baseline augmentations are from the prior
art of [14]. When scaling up UPillars to UPillars-L, our
LidarAugment improves both models, and the gains are more
significant for the larger model, thanks to its customizable
regularization. More results in Table IV.
to significant search cost. Recent studies [15], [16] attempt to
address these challenges by using efficient search algorithms.
Those approaches typically construct a fixed search space,
and run a complex search algorithms (such as population-
based search [17]) to find a data augmentation strategy for
a model. However, our studies reveal that the search spaces
used in prior works are suboptimal. Despite having complex
search algorithms, without a systematic way to define a good
search space, we cannot unleash the potential of a model.
In this paper, we propose LidarAugment, a simplified
search-based approach for 3D data augmentations. Unlike
previous methods that rely on complex search algorithms to
explore an exponentially large search space, our approach
aims to define a simplified search space that contains a
variety of data augmentations but has minimal (i.e. two)
hyperparameters, such that users can easily customize a
diverse set of 3D data augmentations for different models.
Specifically, we construct the LidarAugment search space
by first factorizing a large search space based on operations
and exploring each sub search space with a per-operation
search. Then, we normalize and align the sub search space
for each data augmentation to form the LidarAugment search
space. The final LidarAugment search space contains only
two shared hyperparameters: m∈[0,∞)controls the nor-
malized magnitude and p∈[0,1]controls the probability of
applying each data augmentation policies. Our LidarAug-
ment search space significantly simplifies prior works [15]
by cutting down the number of hyperparameters to two, a
15×reduction in number of hyperparameters.
Despite only having two hyperparamters, our LidarAug-
ment search space contains a variety of existing 3D data
arXiv:2210.13488v1 [cs.CV] 24 Oct 2022