TopoGaussian: Inferring Internal Topology Structures from Visual Clues

Abstract

We present TopoGaussian, a mesh-free holistic pipeline for inferring the interior structure of an opaque object with easily accessible photos and videos as input.

Traditional approaches require intrusive sensors, operate on expensive equipment, or reconstruct surface information only. Our pipeline combines Gaussian splatting with a novel particle-based differentiable simulator for hollowed objects. Based on the gradients from this simulator, we provides two optimizers, including a new shape optimization scheme based on a particle representation, and a method based on neural implicit surface. The resultant pipeline is holistic and meshless, supporting modeling, simulation, and optimization of the interior geometry in a hollowed object on a unified point-cloud representation.

We showcase the results of our pipeline on several synthetic examples and four real-world tasks, involving rigid and soft objects and report the successful deduction of their interior designs that lead to visually plausible motions observed in the video input. Based on the output, we further performed 3D-print and validates the effect of our methods. These results highlight the potential of our pipeline in 3D-vision, soft-robotics, and manufacturing applications.


Rigid Body Results

Initial (solid)
Optimized Results
Optimized Structures
Initial (solid)
Optimized Results
Optimized Structures


frog
pavilion
fish-1
swim-ring
rabbit
cow
toy-1
toy-2
fandisk
hippo
toy-3
bird
kangaroo
stone
pear
pig
spot
teaspot
tumbler
fish-2
Initial (solid)
Optimized Results
Optimized Structures
Initial (solid)
Optimized Results
Optimized Structures


Soft Body Results

Bird


Initial Guess
Optimized Result
Ground Truth
Inner Structure

Pear


Initial Guess
Optimized Result
Ground Truth
Inner Structure




Real-World Validation

Rigid Body

Hawk


Reference (stand still)
Initial Guess
Optimized Result
Inner Structure


Qiqi


Reference (filling water)
Initial Guess
Optimized Result
Inner Structure


Wobbly Doll


Reference (4.0Hz)
Initial Guess (2.4Hz)
Optimized Result (4.0Hz)
Inner Structure


Pear (3D-printed)


Initial Guess (simulation)
Optimized Result (simulation)
Initial Guess (3D-printed)
Optimized Result (3D-printed)


Soft Body

Pneumatic Finger


Reference (bended)
Initial Guess
Optimized Result
Inner Structure


Metrics

Optimization Loss


Volumetric Shape Generation Time


Reconstruction Quality


Comparison of Optimized Inner Structures

Ours
PGSR (voxel_size=0.2)
PGSR (voxel_size=0.05)
Gaussian Surfel (depth=8)

frog
fish-1
swim-ring
cow
toy-1
toy-2
fandisk
hippo
toy-3
bird
Ours
PGSR (voxel_size=0.2)
PGSR (voxel_size=0.05)
Gaussian Surfel (depth=8)