Hi,
I’m working on a car project and need to produce and accurate scan of a entire car body.
Preparation
Scanning
It’s getting better but I still think the surface quality is not great an I get lots of uneven surfaces
Any idea why the surface looks like that and how I can avoid it?
Thanks
Robert
Hi Robert,
Is it strong sunlight from above? Or artificial light?
Hi Robert,
Could you please take a look at the message I sent you? We would like to obtain the project file of your model to get more details. Thank you!
I had a LED spotlight coming from this side… maybe I can try to get another light sorce… or use just daylight…/
Thanks
Looking at the markers it looks like the resolution was set on a high point of the distance was out of the good zone
You should get much better results than this .
You don’t need any light source when scanning using infrared scanner, I would avoid too much of any light
Hi Robert, after sending your issue to our R&D team, they think that your scanning scene setup is done very well! 
You only took 32 photos, which is too few and may affect the accuracy of the scanned model. You can try taking more photos before processing the calculation.
You scanned 4 parts and then merged them. The results of merging multiple parts may not align well, causing point cloud overlap and affecting surface smoothness.
If the exposure of the depth camera is not properly controlled during scanning, being too far from the car with the MIRACO Plus can result in underexposure or being too close can lead to overexposure, both of which can cause this uneven phenomenon.
You can try taking more photos, around 100 or more, and directly generate a larger global marker frame. This way, you can try scanning the entire car at once or merging only 2 or 3 parts.
When scanning the entire car based on the global marker frame, it is best to keep the scanner stable and move slowly to avoid poor point cloud alignment due to instability. You can even use single-shot mode to scan the entire car region by region to avoid shaking.
If the scanning result of a certain part is not good, you can rescan that part using the same global marker frame. Then, directly crop and merge it with the previously scanned model (at this point, the exported point cloud model position and orientation will be aligned directly, and no additional alignment is needed), replacing the problematic areas. This should also be feasible.
Regarding the scanning distance, position the scanner at the recommended distance between 0.8-1.3 meters until the coded targets are clearly visible. Try to keep the depth camera displaying gray or with some small areas of blue.
You can also watch this video: MIRACO Plus & Photogrammetric Metrology Kit: How to Scan a Car Using Global Markers or the PMK
I hope this information can help you. If you have any further questions, please feel free to communicate with us at any time.
thanks, will try some of your suggestions
Can you explain what you mean with:
resolution was set on a high point of the distance was out of the good zone
When I look at your scan I see that the point distance is set too low or you scanned with greater distance that it should , the details have low accuracy so or you scanned at greater distance than GOOD or your fusing/ meshing setting was on low .
It is hard to pin point it the issue just from looking at the image.
Structured light scanners need to be at Excellent/Good distance to provide the best sharpness and quality of the capture and should be consistent on each section you scanning to preserve the same accuracy.
Scanning a car can take sometimes to 12 hours to capture the all sections , don’t try to capture too big section ensuring you keep the same distance while capturing it.
thanks for the feedback. I will try again and show the result
do you recommend using the PMK with coded targets and the 4 scale bars or only with normal marker dots?
In my scan the coded targes are also shown as small bumps on the surface, which is not very even.
Hi! The lower „2" only impacts the color capturing exposure, but would be grayed out unless you activated color capture.
Exposure “1” is “the” important exposure. Next to keeping the optimal distance this is crucial for good scans. Red means overexposed. Blue means underexposed. Ideally, you want to have just a little bit of red and very little blue. I always try “auto” first and look how the auto adjustment reacts during the scan. It normally adjusts just fine for surfaces of uniform properties (which should be the case for your car body). If it doesn’t react to my expectation, I set the exposure manually according to the rule above (regarding red/blue).
thanks great advice
You suppose to use it , you can remove the bars before scanning or place them in areas where they don’t disturb the surface while scanning, the whole point of PMK of using coded targets. Other way you can just use Global Markers and don’t bother with PMK
