From 3D Models to 3D Prints: an Overview of the Processing Pipeline <s> Meeting fabrication requirements <s> Printability, the capability of a 3D printer to closely reproduce a 3D model, is a complex decision involving several geometrical attributes like local thickness, shape of the thin regions and their surroundings, and topology with respect to thin regions. We present a method for assessment of 3D shape printability which efficiently and effectively computes such attributes. Our method uses a simple and efficient voxel-based representation and associated computations. Using tools from multi-scale morphology and geodesic analysis, we propose several new metrics for various printability problems. We illustrate our method with results taken from a real-life application. <s> BIB001 </s> From 3D Models to 3D Prints: an Overview of the Processing Pipeline <s> Meeting fabrication requirements <s> Purpose – Given an intersection-free mesh surface S, the paper introduces a method to thicken S into a solid H located at one side of S. By such a surface-to-solid conversion operation, industrial users are able to fabricate a designed (or reconstructed) surface by rapid prototyping. Design/methodology/approach – The paper first investigates an implicit representation of the thickened solid H according to an extension of signed distance function. After that, a partial surface reconstruction algorithm is proposed to generate the boundary surface of H, which retains the given surface S on the resultant surface. Findings – Experimental tests show that the thickening results generated by the method give nearly uniform thickness and meanwhile do not present shape approximation error at the region of input surface S. These two good properties are important to the industrial applications of solid fabrication. Research limitations/implications – The input polygonal model is assumed to be intersection-free, where ... <s> BIB002
Herewith we distinguish between requirements of the shape and requirements of its representation. Shape requirements are printerspecific, and define rules for the compatibility of the geometry with the printing hardware. Representation requirements guarantee that the (tessellated) geometry to be printed actually encloses a solid without ambiguity. 3.1.1. Shape requirements 3.1.1.1. Checks When the input model comes in raster form (e.g. a voxelization), BIB001 provides the means to analyze the shape and identify problematic regions whose size drops below the printing resolution (e.g. thin walls or other tiny features). In a slightly more general setting, [RNDA13] describes an approach to estimate the thickness of triangulated models. 3.1.1.2. Automatically fixing the input While the previous works are meant to detect possible incompatibilities, in BIB002 an algorithm is proposed to actually thicken sheet-like structures so as to make them printable. In [SVB * 12] a similar approach is presented with a focus on the structural characteristics of the printed prototype: note that this method is not meant to make the model printable, but it shares several aspects with the previous one. If the model cannot fit into the printing chamber due to its size, [LBRM12] proposes an approach to split the model into parts that can be printed separately and reassembled after printing. Apparently no publication deals with the automatic placement of drainage channels for models with internal cavities to be printed with powder bed technologies.