Q1. What can I 3D scan?
Generally, you can scan all visible not-too-shiny surfaces that do not move for at least a few seconds of scanning time. The 3D scanner range we offer can scan an object size of 60-500 mm, but can be adapted for scanning small objects with fine details or larger object like a car engine.
The best objects to scan with this 3D scanner are:
- Bounded by the specified 60-500mm in any dimension
- Opaque, not translucent/transparent
- Not-too-shiny surfaces
- Asymmetrical, with abundant scan alignment features
Q2. How does the HP/DAVID 3D scanner work?
HP/DAVID 3D scanners use structured light technology which casts light patterns onto an object. The 3D scanner produces an accurate 360° digital representation of the physical object by fusing single dimension scans that are captured at different angles. The 3D scanner captures the 3D surfaces as a triangle net (point cloud plus connecting triangles) at accurate scale. Textures and color can be captured as well so you can get a colored model. The latest 3D scanning software comes with new structured light patterns that enable the scanning of shiny surfaces as well.
Q3. Can I scan an object larger than 50mm?
Yes, but you need to create a custom large scale calibration panel with a 90° corner using patterns included in DAVID's software. You may also want to take a series of smaller scans to achieve the desired resolution, instead of scanning the large object in one go. The calibration patterns are included as PDF and CDR files in the software. You can find them in your Windows Start menu under Programs -> DAVID -> Printout. You can print them in any size to fit the object you want to scan.
Using DAVID’s 3D scanning software, you can scan objects which are several feet long with just a single scan. However, more typically, users would choose to take a series of smaller scans and have DAVID’s software auto-align and fuse the scans into one 3D image. The reason for this is because the resolution of the scanner is related to the scan size being used. For each pixel of the camera, a point is formed in the point mesh cloud of the 3D image. Therefore, as the scan size gets larger, the resolution of the image gets less, as the pixels are spaced out over a larger area.
- Scanning long a 5ft. long object in one go with an SLS-3 (resolution of 0.05% of scan size) would produce an image with precision limited to 0.03”
- Scanning a 5ft. long object with a series of 1ft. overlapping scans would increase to 0.006”. Using smaller scan sizes could improve this resolution further until a limit of 50 microns (under 0.002”) is reached.
- There is negligible difference in the scan size range between single camera and a dual camera system working in stereo mode (the area being scanned remains the same size as for a single camera scanner). However, in extended mode, there's a larger scan field, so presumably the scan area will be a larger rectangular shape. DAVID does not quantify what the increase in size would be, but it will obviously be a function of how far apart the areas of focus are for the two cameras.
- If the camera and projector have not been moved and their focus is not changed, the scanner does not need to be recalibrated.
Q4. Can I scan smaller objects than 60mm?
Yes, but you need to customize your calibration panel and adapt lenses to focus on the small object. You can see how our customer Eric managed to scan a human tooth by customizing the setup, here.
The calibration patterns are included as PDF and CDR files in the software. You can find them in your Windows Start menu under Programs -> DAVID -> Printout. You can print them in any size to fit the object you want to scan.
Q5. Can I scan shiny surfaces?
The surface must not be too shiny. Cover highly reflective, translucent, or very dark surfaces with a coating spray such as Magnaflux Spotcheck.
When you shine light at an object which absorbs or reflects too much of the light, the light on the surface of the object is not visible. Consequently, the camera will not be able to capture sufficient data for software to be able to create a 3D model. The DAVID SLS-3, with the latest DAVID5 software, performs very well due to the new structured light patterns compared to other structured light 3D scanners.
Better scanning performance is available, without coating, using alternatives such as blue LED technology. This does come at a significantly higher price though, with many systems costing over $100,000, as can be seen on this 3D scanner comparison page.
Q6. How does it compare to other products in the market?
HP/DAVID 3D scanners offer the best value for money for the accuracy it can achieve. Read what our customers are saying in our Case Studies who compare the DAVID 3D scanners to Artec or Next Engine or Kinect 3D scanners.
Q7 Can I download a 3D scan file sample?
You can download samples from our Support & Training page
Set Up Questions
Q8. What's the best way to successfully calibrate?
Start calibrating with the mid-point and then calibrate smaller or larger sizes. It's easier to calibrate this way.
Q9. Do I need calibration panels during scanning?
No, you should remove them. After calibration, you can move the whole scanner, but you must not move the camera or projector on the red bar.
Q10. What is the best distance between the camera and the object?
The camera and the object should be as close as possible, so that the camera can see the scanned surface and not much more.
Q11. What is the best distance between the camera and the projector?
The intersection angle (angle between camera view direction and projector direction) should ideally be between 20° and 25° for single camera systems. For stereo setups, set both cameras between 10° and 15
Q12. Do I need a dark room for scanning?
Generally darker is better for scanning. Direct sunlight is too bright, but some environment light is OK; you don't need complete darkness. It is most important that the environment light is constant during scanning, and the laser (or projector) must be clearly brighter in the camera image than everything else.
Q13. How mobile is the 3D scanner? When do I need the calibration panels?
You can carry your structured light 3D scanner in a Pelican Briefcase and set it up anywhere. We have carried it to different shows! The 3D scanning is performed without calibration panels, you only need them to calibrate the scanner before you start scanning. If the camera and projector are not moved and their focus is not changed, the scanner does not need to be recalibrated.
Q14. How can I fine tune the Projector?
The projector should be set up correctly for use upon unboxing. However, if the projector input source has been accidentally set for an analogue, rather than digital input, it will require correction.
To check this, please switch on the projector and focus the projected image of the Acer screensaver at a convenient flat surface.
In the bottom right hand side of the image you will see some writing. After a few seconds this will change to a symbol with “No Signal” alongside it. However, initially it will show the input source – either HDMI/MHL or D-Sub. If D-Sub appears then the projector will not be looking for an input via the HDMI cable, which could be the cause of your problem.
To alter the input source, press the square ring in front of the menu button, on the top of the projector. (You should also see that the word “Source” in raised unpainted letters on the projector case, just in front of the square ring). After pressing the ring, you will see the Source menu projected. Pressing the same front section of the ring switches the input source between D-Sub and HDMI. Pressing the ring to the right of the menu button confirms the selection.
You need to make sure that the HDMI/MHL line is highlighted in Gold, with the D-Sub line having a black background.
Application Questions: What can I do with the scan data?
Q15. Does DAVID software work with Solidworks?
The 3D image generated by DAVID’s 3D scanning software is a “point cloud” mesh. This can be exported in industry standard .stl, .obj and .ply file formats. Each pixel of the camera sensor represents a point in the point cloud, so potentially these file types may contain much more data than a traditional, parametric solid, CAD program may be able to handle.
Some data manipulation software has limitations. For example, the 2016 and 2017 versions of SolidWorks can handle an .stl file with up to 0.5m facets, whereas the camera on the DAVID SLS-3 can generate 2.3m points (1920 x 1200) from just one scan. A fused image of several overlapping scans will therefore typically contain more data points than SolidWorks can handle. One possibility to overcome this is to reduce the mesh density of the scan image prior to exporting from DAVID (as explained on the HP 3D Scan FAQs web page), but this will typically compromise the quality of the scan model. A second solution may be to use a combined mesh editor and CAD program, such as Spaceclaim (or Geomagics), but this is unlikely to be ideal if you already have SolidWorks. A further alternative, as you have suggested, would be to utilize software like Netfabb to smooth meshes and reduce the number of points in the cloud, to enable importing into SolidWorks. Other .stl file editors may potentially achieve the same aim, such as MeshLab, MeshMixer and Blender, all of which are free to download. IGES files may also work as getting scanned images into Solidworks.
If you wish to test if your existing software, or other software you may contemplate acquiring, is capable of handling the files generated by DAVID’s software, trial scans in .stl and .obj file formats are available from this download page on HP/DAVID’s website. The old DAVID user forum may provide some insight, as there are several mentions of SolidWorks in various forum discussions.
Q16. Can the 3D scan data be used for 3D printing or milling?
Yes. DAVID does not create a machine program that drives your printer/CNC, but these machines usually have software that can import 3D triangle meshes.
They usually require a water-tight 3D model, a model which has no holes, so that inside and outside are clearly defined. DAVID's single scans are not closed, but the last processing step in DAVID, the Fusion, can create water-tight models.
Q17. Can the data be used for measurements, comparison, or analysis?
Yes. The Enterprise version of our DAVID software offers some measurement and mesh comparison functions. In addition, DAVID exports in standard 3D file formats (OBJ, STL, PLY) which third party software can import for analysis. The 3D data are at absolute scale (usually in mm).
Q18. What software can I use for 3D measurements?
MeshLab is free and offers point-to-point distance measurements. Rhino3d and Geomagics are other powerful 3D software programs.
Q19. Can I export point clouds?
DAVID exports to the OBJ file format. It is an ASCII text file that contains a 3D point cloud plus triangles, surface normals, and texture coordinates. If you are interested only in the point cloud, read all lines that start with V. Each line stores the X, Y, Z coordinates of one 3D point. The reference coordinate system is the center of the calibration corner, with the Y axis pointing upward.
Q20. Can I import the 3D scan files into my 3D software?
Look for an import function for OBJ, STL, or PLY files in your software. Some programs might require an import plugin (with or without cost).
You might also be able to find a conversion tool to convert OBJ or STL into the format that you need.
For a more detailed FAQ, take a look at the DAVID FAQ page