Comparing stl data with cloud point

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ziarehmann
Posts: 10
Joined: Thu Jul 06, 2017 7:50 am

Comparing stl data with cloud point

Post by ziarehmann »

Hi,

I am new user of cloud compare as a matter of fact image comparing as well. I have a cad model in stl format (that can be also converted in point cloud as well). And i printed that model with a 3d printer and scanned it using a panasonic distance sensor. I am tyring to compare both models to see how good or bad is the 3d printed model. the issue i seem to have is roughly they are sames shapes but with different scales and the most important they are mirror image of itself(see image). Till now i amnot able to align both models in cloudcompare. Can anybody guide me what is the issue or how to align both models. tried to go through as stated in tutorials but was not able to do that. Hope to hear from your side soon.
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daniel
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Re: Comparing stl data with cloud point

Post by daniel »

If it's mirrored (like one dimension only is inverted?), then you should try to make that dimension fit with one of the main axes (X, Y or Z) and then use the 'Edit > Multiply / scale' method to multiply this dimension by -1.

Then you can use the point-pair based alignment tool (http://www.cloudcompare.org/doc/wiki/in ... itle=Align) to both register and rescale the entities.
Daniel, CloudCompare admin
ziarehmann
Posts: 10
Joined: Thu Jul 06, 2017 7:50 am

Re: Comparing stl data with cloud point

Post by ziarehmann »

Hi,

I am still not able to properly scale the two models (stl and cloud point). I tried to align both models which seems to be working but the scale seems to be out of sync. I dont understand why this issue as i have scanned the exact same model as shown in stl file. Any ideas?

Thanks
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daniel
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Re: Comparing stl data with cloud point

Post by daniel »

Have you let the scale change during the registration process? (with the 'Adjust scale' option)
Daniel, CloudCompare admin
ziarehmann
Posts: 10
Joined: Thu Jul 06, 2017 7:50 am

Re: Comparing stl data with cloud point

Post by ziarehmann »

Hallo Daniel,

Yes i even try to do that. But that was also not helpfull.
ziarehmann
Posts: 10
Joined: Thu Jul 06, 2017 7:50 am

Re: Comparing stl data with cloud point

Post by ziarehmann »

Hello All,

I rechecked my data as i though that migh be due to the measurements done rather than scale issue. And i found out one of the encoder values were not in sync with other data. And that leads to the different scales. After removing that error. I am able to register both models. Thanks for the support
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