Papers for

3d printing service providers

Papers whose findings have a practical use for this group, as judged from the abstract. Open a paper to read what it means in practice.

UniBRep generates detailed 3D CAD models from single images

UniBRep: Learning Unified Geometry and Topology for Image-conditioned B-Rep Generation

Abstract: Generating a boundary representation (B-rep) conditioned on a single image requires faithful reconstruction of geometry, valid topology, and support for complex shapes. We present UniBRep, a geometry-first framework that adapts a pretrained image-to-3D model to generate a feature mesh as a unified intermediate representation. Its surface provides a geometric scaffold, while spatially aligned learned features encode face-separation cues for topology recovery. Dual decoder branches generate the geometry and face-separation features; a geometry- and feature-guided construction pipeline then fits parametric surfaces, recovers boundary curves and connectivity, and assembles an explicit B-rep using a CAD kernel. Recovering topology from mesh regions avoids predefined architectural face-count limits, allowing face count to scale with shape complexity. On the standard DeepCAD benchmark, UniBRep produces valid B-reps for 80.49\% of inputs and reduces face Chamfer distance from 0.1096 to 0.0345 relative to CADDreamer. In a matched comparison, UniBRep also outperforms the HoLa public demo across all reported metrics. Further evaluations demonstrate scalability to high-complexity shapes beyond the standard 30-face range, generalization to objects outside the CAD training distribution, and qualitative transfer to real photographs.

Fri 2 OctComputer Vision and Pattern RecognitionGraphics
The gist
Creating accurate 3D CAD models from a single image is hard because the model must have the right shape and the correct connections between surfaces. The authors propose UniBRep, which first builds a shape with a mesh that guides how the surfaces connect. It then refines this into a full CAD representation with valid curves and faces using learned features. Their method improves accuracy and works well even for complex shapes and photos it was not trained on.
Open → 2610.04092v1

Automated 3d camera measures thickness of bioprinted tissue constructs

An Automated Thickness Evaluation Procedure Using an Integrated Structured Light 3D Camera in a Robotic Bioprinting Framework

Abstract: Bioprinting is emerging as a tissue engineering technique to replace common treatment methods for large scale injuries. While thickness of the BioPrinted Constructs (BPCs) have shown to be of importance in the cell maturation and integration, the literature lacks a robust, automated, and quantitative method for measuring these metrics. In this paper, we propose a fully automated vision-based method for measuring the thickness of the BPCs with complex geometries. Leveraging the point cloud and RGB images of a structured light 3D camera, our proposed method performs an image-based segmentation for delineating the BPCs from the RGB images, accompanied by novel geometry-based thickness measurement algorithms performed on the point cloud scans. These algorithms combine the segmentation mask with the robot's forward kinematics data and a 3D point cloud scan to precisely measure the aforementioned metrics for complex-shaped BPCs. The proposed method was evaluated in simulation and experimental studies. In simulation studies, the algorithms were used to measure the thickness of some virtually created BPCs with known thickness. The comparison between the measured and true thicknesses demonstrates the high accuracy of the proposed method, achieving mean absolute errors between 0.025 mm and 0.057 mm in simulation at a spatial resolution of 0.1 mm x 0.1 mm per pixel. Furthermore, we successfully deployed the algorithms on our robotic bioprinting setup utilizing a structure light 3D camera, where complex patterns were printed and the developed methods utilized to accurately measure the thickness of printed BPCs.

Thu 10 SeptRobotics
The gist
Measuring how thick bioprinted tissues are is important for growing cells properly, but current methods lack precision and automation. This paper presents a fully automated way to measure the thickness of tissue shapes made by bioprinters using a 3D camera that scans the surface and color images to detect the tissue boundaries. The authors combine image segmentation and robot data with 3D point clouds to get very accurate thickness measurements even for complex shapes. They tested their method in virtual simulations and on real bioprinted samples, achieving errors below 0.06 millimeters.
Open → 2609.12206v1