Overview
The Artec Eva uses structured light-based 3D scanning with white light to create its captures. You may need to convert a real life object into a 3D model as perhaps a reference or an asset part of your production (animation, game, etc).
Outside of class time, the scanner — housed in the EML — can be requested via an email to the Post-Production team (postproduction@emerson.edu), typically during the weekdays (Mon - Fri). These requests are considered on a case-by-case basis.
This following article will guide you through the workflow for 3D scanning using the Artec Eva as well as processing the scan data through the Artec Studio 15 Professional software. By the end, the aim is to have a cleanly generated mesh of your scanned object.
Setup
Plug in the power and data cables for the Artec Eva. The power cable is plugged in and tightened via the circular plug on the bottom of the Eva's hilt. Afterwards, plug the power cable into an appropriate outlet. The data cable goes the side of the Eva and then into a USB 3.0 port.
Log into a computer, and launch Artec Studio 15 Professional.
Confirm that the green light on Eva's hilt is on, ensuring it has power and is detected by the software. This light will blink if it is only powered on, and then will cease to do so once Artec Studio 15 Professional is launched and recognizes the device.
Create a new project, File > New Project. Define your project name and the folder.
Scanning
Place the object onto a flat surface. Alternatively, you can also use a turntable to rotate the object while scanning.
In Artec Studio, adjust Scanning Speed (FPS) and the other settings, as needed. If your object has smaller details, consider enabling HD Reconstruction and then increasing the HD data density.
Click the Preview button to see how well the scanner detects the object's surface.
Look at the distance indicator on the left of the interface, make sure the scanner is close to the optimal distance (the bulk of bar graph is in the middle three green sections, this displays detected polygons and their distance) and that the surface of the object is being visibly captured.
Press "Record" once ready. You will notice the surface of the scanned object to be covered in a orange-green-blue gradient, this shows the geometric surfaces that are being scanned as well as how far away those surfaces are from the scanner. Your aim is to have as much of the object visible and green as possible, while referring to the distance meter to the left.
Rotate the turntable or slowly move the scanner, keeping the object in view. Try not to move the scanner or the object too quickly or harshly, otherwise the scanner may lose track of the object.
Mesh Generation
Once you have finished scanning your object, your next step is to clean up your scan data before generating your mesh.
On the right side of the Artec Studio software, you will see a list of all your scans.
If you had "HD Reconstruction" enabled prior to scanning, this process will initiate once the scanning session is finished. A loading bar appear at the bottom of the window while "HD Reconstruction" is active. You will have to wait until this is done.
Once done, additional "HD" versions of the scans will appear in your list of scans on the right.
Note: The HD Scans in this screenshot have already been cleaned up, and as such they have a lower Error and File Size. HD Scans will increase the file size of each scan, and not lower the Error rating.
Once you have made all of your scans of your object, you can click Autopilot which will guide you through each stage in mesh generation.
First you will be asked to select the scans you wish to use. Ideally choose the scans with the least visible problems and make sure you have enough to cover for the entirety of your object. At times, you may find that some of your scans' frames are unaligned or "smeared", and do not look like a unified object. During the fusion process, when the scans are combined into a mesh, those frames may be automatically aligned, fixing the issue. If not, then it may be best to exclude those scans. If you find that your individual scans look fine, but they are all misaligned and are not yet together, do not worry as there will be a step allowing you to address this.
Once you have selected your scans, you will be brought to the "Model Creation" window.
Some of the fields will be auto-generated. However, if you are doing this process on one of the EML computers, you may set the Model Resolution down to 0.5 to get the finest detail possible with the Artec Eva. If you are using a different model (i.e. Artec Spider, Intel RealSense, Kinect) of scanner, this number will differ depending on that model. Do note that this will result with a mesh with a high polygon count, so tweak this value as it would best serve your project.
For Texture Resolution, set this as appropriate for your project.
Next, you will enter the Editing stage. Here you will clean the scans of any geometry or data that will not be included in the generated mesh such as the top of a counter or a turntable. Your scans may, at first, look like the following:
Once you begin editing, your individual scans will be in different colors within the viewport window.
While using the viewport, the camera is controlled by clicking and dragging on of the three mouse buttons.
- Left Mouse Button rotates the camera view.
- Middle Mouse Button pans the camera view.
- Right Mouse Button zooms the camera view in/out.
For clean up, you will like use the Eraser tool. By holding Ctrl while clicking and brushing over parts of your scan(s), you will see your selected geometry in red. This control method is the same across most, if not all, of the different modes. Once selected, pressing the Delete key or the Erase button on the interface will get rid of those scanned surfaces.
- 2D Selection will select based on what your camera view can see.
- 3D Selection will select along the actual geometric surface of the scans within a spherical radius.
- Rectangular and Lasso select within their respective shapes, with Lasso allowing you to freehand.
- Cut-off plane selection draws a flat plane at the surface you brush over. Anything below that plane will be selected, and can be deleted. The height of this cut-off plane can be adjusted by holding Ctrl+Shift and scrolling the mouse wheel up/down accordingly.
- Base selection will attempt to select what it believes to be the bottom base of your scan(s).
Once you have cleaned through your scans, they may look like the following:
You will now be in the Alignment stage.
Typically, if your scans are similar in form and have common overlapping surfaces then Auto-align should be enough. However, if you have scanned different sections of an object and Auto-align does not know what to do, then you will need to Align scans manually.
To the left, you will see a section listing all of your scans. The ones with the blue dots are "registered" or are considered to be aligned, meaning they can be used as a reference. Meanwhile the green dot represents the unregistered scan, which is the one you will be aligning to the rest of the scan(s).
If you have several scans, you should work on aligning one at a time with your registered scan(s). Examining the scans using the viewport, hold CTRL then Left click on a point or feature you're using as reference on one of the scans. Then examine the other scan to find the matching location or feature, and mark it holding CTRL then Left click.
It is recommended to find at least three common points between whichever scans you are lining up. Once done, you will see several lines drawn between your common points:
Once you have finished marking your scans, click Align. Check to see if your scans align as expected.
For more information about this process, please refer to the respective documentation for the Artec Studio software or ask a lab assistant for additional support.
If all your scans are aligned correctly and they all come together to approximately form your object, then you should be all set with this step. Hit Apply, and then proceed onwards. Do not worry if there are a few jagged imperfections, artifacts, or scanning errors as they may be fixed during the fusion process.
From here on, wait until the scans are done fusing together into your mesh. Once finished, it will appear in your viewport and be marked in your list as "Sharp Fusion". Having this selected, you may export the mesh by going to File Export Meshes. This will output either an .obj or .ply file, a material (.mtl) file, and an image texture (whose format you can choose).
Conclusion
With that, this has been a broad overview of the 3D scanning workflow using the Artec Eva. If you have any further questions, please do not hesitate to reach out to a lab assistant over at the EML Annex (Ansin 314) for in-lab support, or email either the EML manager (eugene_kuznetsov@emerson.edu) or the Post-Production team (postproduction@emerson.edu) your questions.