  This paper presents a novel framework to learn a concise geometric primitive
representation for 3D point clouds. Different from representing each type of
primitive individually, we focus on the challenging problem of how to achieve a
concise and uniform representation robustly. We employ quadrics to represent
diverse primitives with only 10 parameters and propose the first end-to-end
learning-based framework, namely QuadricsNet, to parse quadrics in point
clouds. The relationships between quadrics mathematical formulation and
geometric attributes, including the type, scale and pose, are insightfully
integrated for effective supervision of QuaidricsNet. Besides, a novel
pattern-comprehensive dataset with quadrics segments and objects is collected
for training and evaluation. Experiments demonstrate the effectiveness of our
concise representation and the robustness of QuadricsNet. Our code is available
at \url{https://github.com/MichaelWu99-lab/QuadricsNet}
