Despite the fact that the industrial design business has migrated to CAD modelling and drafting, many manufacturers and fabricators still maintain legacy designs in the form of 2D paper drawings and blueprints. There are many engineering design organizations whose design engineers and consultants like to start with a hand drawing.
However, these 2D paper designs are just physical drawings. They need digital backups (digitized drawings), which engineers require in vector form (like in CAD) so that they may be edited without difficulty. This article serves as a guide to all you need to know about Converting 2D drawings to 3D models in CAD format and turning the raster into a CAD 2D or 3D file.
Right Time for Converting 2D Drawings to 3D Models Using Computer-Aided Design (CAD)
One of the most common instances in which CAD scanners and drawing scanners are used is to convert legacy designs from 2D paper to CAD drawings. As an example, as a design business, you may have formed collaboration with a manufacturing company to offer designs for a specific product, such as a sheet metal commercial kitchen counter. You’ve already completed many projects for the same sector and dealt with similar tasks.
As a result, your engineers and CAD drafters are experts at it, and collaborating on a 3D CAD modelling project is a piece of cake. And, with a few tweaks and different CAD specifications, the designs for this newly packaged project are also rather standard.
However, since all of your previous deliverables were drawn on physical paper or drawing sheets, you won’t be able to import the pieces from there. From the counter to the steel frame, cabinets, girders, and everything else, you’ll need to redraw the full commercial kitchen counter and stalls. It will result in a longer engineering design cycle as well as delays in approvals. Your design business has a good possibility of losing it to a rival who has been using AutoCAD for a long time.
Such are the times when you need to scan the designs, scale them up in AutoCAD, and share them with the customer—in this case, the manufacturing business. Rather than starting from scratch, this saves time, money, and effort by channeling energy, time, and effort in a more effective direction.
If the commercial kitchen countertops manufacturing company already has these AutoCAD files, they won’t need to work with the CAD service provider. When there are minor design changes, a mid-skilled in-house drafter will handle them.
The Importance of Raster and Vector Files in Converting 2D Drawings to 3D Models Using CAD
One thing is clear: 2D paper drawings and hand drawings are only good for initial reference, and drawing editing is difficult. By converting 2D drawings to 3D models using CAD, they must be turned into a blueprint vector. Translating 2D paper designs into DWG formats and then into DXF files for smooth production integration is referred to as digitized drawing. These are vector formats that store a lot of information about each individual drawing element and may be read by CAD applications like AutoCAD.
Second, vector files are resolution independent, which means that no matter how much the item is zoomed in on the screen, there is nearly no distortion. While raster graphics are made up of pixels, vector graphics are made up of objects such as lines, arcs, B-Splines, Poly-lines, and other kinds of curves such as Bezier. Each of these distinct entities may be readily edited by the designer or CAD operator without influencing the remainder of the product.
When 2D paper drawings, such as photos, hand drawings, sketches, and blueprints, are scanned using machines, they are transformed into vectors automatically. Automatic tracing and scanning give the benefit of accuracy while also saving time.
Assessing the Scanning Suitability of 2d Drawings
Once the designer and manufacturer understand the differences between raster and vector file formats, as well as the necessity of using vector formats such as DWG and DXF files, the next issue is what types of drawings may be scanned.
Conversion software can only operate and give results if the inputs are of high quality. When determining whether or not a drawing may be transformed, the size and clarity of the drawing must be considered. Some designs and blueprints are much too tiny to be scanned, and attempting to compensate with resolution may cause the remainder of the scan to fade, lowering the scan’s trustworthiness.
Another thing to consider while evaluating drawings is the degree of line obscurity in the drawings. It will be practically hard for the drawing scanner to understand the sketch if there are too many lines overlapped by texts and footnotes for manufacturing instructions.
CAD drafters should begin converting to CAD designs by selecting the appropriate scanner and predefining the quality, colour, and output with the customer. In monochrome or grayscale, the most acceptable input resolution is between 200 and 400 dpi. TIFF files are the preferred format for scanners, but alternative formats like BMP and PNG are also extensively used. JPEGs are also often avoided since they tend to compromise picture quality and hence design intelligence.
Cleaning Up Before CAD Conversion
Before beginning the raster to vector conversion, the CAD drafter must correct certain fundamental problems. Unwanted parts are often added during scans, which are simple errors that make it difficult to interpret the file while creating CAD models or drawings.
To fill in the missing gaps and holes, tools such as “Remove Holes” for small holes and “Flood Fill” for large gaps are utilised. Simultaneously, the “Smooth” and “Eliminate Speckles” capabilities will remove hairs and irregularities from the line, as well as markings scanned from the paper and any background noise.
Choosing the Right CAD File Format: DWG or DXF
After the pre-conversion cleaning is complete, the CAD design engineer must choose a file format that will allow for efficient downstream processes. However, DWG and DXF are the most widely used formats. Both of these enable you to alter specific entities, reuse them, and save time in the future when creating comparable pieces, such as the commercial kitchen counter in the example above. Both of these formats are vector formats, which means they share all of the characteristics of a vector file.
However, a DXF file is a more universal file format that can be read by any CAD programme and may be used to transfer data from AutoCAD to SolidWorks or Inventor. DXF files are also useful for identifying important places and establishing N-Codes and G-Codes for creating CNC machine programmes. Because converting from DWG to DXF and vice versa is always feasible, choosing a file format should be dependent on the next step in the product design process.
2D Paper to CAD/Raster to Vector Conversion
The technique is the same whether you’re converting from TIFF or PDF to DWG or DXF.
The file is first imported into the appropriate CAD scanner and CAD converter, and the kind of drawing is selected to determine the proper vectorization setting for the conversion.
Simply click on vector after selecting the portion you want to turn into a vector.
Saving this file and adjusting the preview will enable you to experiment with various parameters before saving your favourite. To verify the correctness of the drawings in CAD format and preserve quality, the designer or project engineer cleans and patches them after conversion. When there are several scans to be converted to CAD, there is also a batch processing tool to automate the procedure.
Although the procedure seems straightforward, it requires a high level of knowledge and experience in order to attain the requisite precision and quality in the final CAD models and drawings. The easiest way to achieve this is to work with an offshore CAD design and scan to CAD conversion business with extensive expertise and a physical presence near you.
