Working with point cloud meshes

Hi all,

I have been working with my point cloud meshes out of my Matterport space scans and I'm finding that the initial mesh quality is not that great - it's acceptable but isn't to the standard that I was expecting.  I have had to spend many hours using products like MeshLab to improve and refine the mesh as I felt that I couldn't show the original meshes to my clients.

My question is, has anyone worked directly with Matterport to seek to improve the point cloud meshes?  Or at least to have used products like MeshLab in such a way that the resulting mesh was of an acceptable standard for distribution?

If anyone from Matterport reads this post then please get in contact with me as I would be happy to share my feedback in more detail - I would also be delighted to partner with Matterport to work out improvements to point cloud production as this would save a lot of time for Matterport Service Partners but, importantly, also our clients.

Best Regards,

Gordon

Partner and Co-Founder

Captured Realities

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Comments

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  • Hi @Gordon Ricketts  Are you referring to Point Clouds you are getting from Matterport or meshes you get from the OBJ file?

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  • Hi William,  I am referring to point clouds from Matterport.  In my particular case, I had a client who only had AutoCAD LT so I had to provide a DXF for them which is why I got into looking closely at the mesh - As otherwise, my client could just have used features within AutoCAD to attach the point cloud directly into a drawing.

    I guess what I am looking for here is some input from the community on workflows relating to dealing with Point Cloud data especially when that output would typically end up in AutoCAD.

    Thanks for your help.

    Best Regards, Gordon

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  • @Gordan If you want to import into a program like ReCap or Revit, then you'll want a Point Cloud.  Matterport has a beta point cloud program.  It's under Download a Point Cloud in the following link:

    https://support.matterport.com/hc/en-us/articles/208932878-5-Download-OBJ-File-Optional-

     

     

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  • Hi Tim, Thanks for the reply but that wasn't really my question.  I am already using ReCap to index point cloud scans that I have requested via the Matterport beta download.  The question here was different in that for one particular client of mine I have had to create a DXF output for him from the point cloud data (as he is using AutoCAD LT which doesn't support point cloud attachment).  What I then discovered was that the quality of the mesh (I'm using meshlab for repairing the mesh) was not as good as I had expected.  This meant that it took me the best part of a day to get the mesh looking better.  So, I was wondering if anyone in the community or at Matterport had done any work to improve the meshes derived from point cloud data?

    I hadn't really expected to have to work on meshes myself as I had hoped to simply pass a client an RCP file (from ReCap) for them to attach to AutoCAD.  I'm finding, however, that some clients don't have a great knowledge of point cloud manipulation and they are expecting that I will be the expert and will help them - which I'm fine to do but clearly I would need to charge for additional services and it crosses into the domain of the AutoDesk ecosystem (which is costly).

    Thoughts from anyone?

    Best Regards,

    Gordon

    Partner and Co-Founder

    Captured Realities

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  • Hi Gordon,

    I am in a similar position as I have to convert files for my clients as well. I am using the same conversion programs; Meshlab, Cloud Compare, etc. and I'm finding that depending on how our original Matterport Scan turns out, will depend on how clear the mesh is.

    I take Extra scans of any space I know will be used for rendering but with the Matterport measurement accuracy not being 100% we are bound to come up with an imperfect mesh. 

    I know I've said nothing to answer your question but figured I would chime in and let you know I am in a similar situation and hopefully there will be more progress in this area!

    I've attached a snapshot of a scan I did of two deck lockers on a sailing yacht and the mechanical engineer was successfully able to use this for his renderings. 

     

     

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  • Hi Ashley,

    Thanks for replying and for your contribution.  Great news that you managed to produce a mesh for the engineer to use and an impressive use case for the Matterport scanner there.

    I have been talking to some laser scanning experts today and they were reminding me of the inherent limitations of point cloud data alone for 3D modelling e.g. reflective surfaces create holes in the model.  I was reminded that I should use multiple means of acquisition and include photographs (or drone footage even) and use photogrammetry techniques to improve the quality of the final mesh.  I have been reviewing other software today and one that stood out was ContextCapture from Bentley.  So I'm a bit less concerned now as I can seek to improve the mesh with the help of other software (and experts in the field)

    I'll keep you posted of my progress or follow me via http://capturedrealities.com.

    Best Regards,

    Gordon

    Partner and Co-Founder

    Captured Realities

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  • Not really an answer but maybe a tip... Providing more scan points in areas can definitely improve the mesh quality.  Sunlight will wash out the mesh as well, so scanning at night might be helpful to avoid holes in the mesh.  Black surfaces like pianos or cars can cause the mesh to collapse.

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  • I have encountered issues with programs like Meshlab in the past with high density cloud-points obtained from industrial grade scanners and discovered, as often is the case, you get what you pay for.

    Meshlab is free and while its very good for a free app the quality is no where near that of paid applications.

    DXF is mostly a dumb file format and isn't supplying as much information as is possible via other formats.

    Like most things trial and error is the way forward, it'll be interesting to see how you progress.

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  • Please help!!

    We are interested in using the PC in software like Revit and Autocad.

    Recap Pro does not seem to utilize the Matterport xyz format to relocate (according to Autodesk) to our local site controls.

    The Matterport survey included at least 3 control points which we thought would be sufficient to lock in the location. If Recap can not be used, then does FaroScene work? If not any other solution would be greatly appreciated

    regards

    David

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  • Hi David,  Can you expand on what you mean by "relocate to our local site controls" please?  I can use Recap Pro to produce a 3D mesh using the Matterport xyz file - it works well in fact.  I then use other tools to manipulate the resultant mesh.  Admittedly I am not a Revit user, however, I use FME to transform the output into a number of different formats.  Best Regards, Gordon

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  • Hi Gordon, thanks for your swift reply.

    Our projects have site control markers on walls, these are effectively x,y and z coordinates, which will lock its rotation, position and vertical height to the BIM.

    The issued PC is in the wrong location, Matterport says the file is automatically registered.

    Ideally we use PC software to locate the PC before we export to Authoring software, not use the Authoring software to locate ( hope this makes sense).

    We want to use the PC not necessarily the mesh.

    Regards

    David

     

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  • Hi David,  I would like to be able to help you but my knowledge of BIM is currently limited.  Perhaps someone else in the AEC community can answer this from their experience?  I would have thought that you should be able to do what you're trying to achieve using a Matterport camera and in the same way it would work on any 3D laser device to BIM modeling.  If you could share some additional details on how to set up these markers and the exact process then I would be happy to scan a test space and try and reproduce your setup.  I'd be happy to help any way I can.  Thanks, Gordon

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  • When we say that the point cloud comes pre-registered, we mean that the individual sweeps (or locations where you captured 3D data) are already registered together to each other. You don't need to go into recap and take each scan location's point cloud and register them together. 

     

    We do not specifically search out site control markers.

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  • Daniel, Thank you for clarifying Matterports pre-reg definition.

    Can you offer any assistance on how we can use the .xyz format to coordinate them to our BIM environment. We want to use the point clouds for spacial fit.

    regards

    David

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  • Gordon, thank you also for offering further help.

    Some one in the Matterport world must have a successful work flow for the AEC market, using the PC's for coordination.

    regards

    David

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  • Hi David,  Yes I'm sure that someone will have come across this one.  I'll be interested to see the update.  Offer still stands to collaborate on a project to help resolve this.  Best Regards, Gordon

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  • If you want really great pointcloud files for AEC or BIM you need to use another scanner. MP uses infrared and not laser, so you will never get a good model with an accurate measurement an architect or engineer needs. Of course you can spend hours on optimizing but in my opinion that´s not an acceptable workflow.

    Even if MP uses a software process to optimize data you will get maybe a better model, but this then is not accurate to the real world data anymore.

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  • @Marcus Morba 

    Pretty sweeping statement there, which I think you'll find a good number of professional users of Matterport cloudpoints will disagree with. Have you ever used a Matterpoint point cloud or are you just passing your opinion?

    Every 'case study' I have read either on the Matterport website or more importantly elsewhere in AEC & BIM forums is very complimentary on the accuracy of them. Often with little to no difference between the results from laser scanners over short distances (20-30 feet) and general accuracy between 1 - 2 % which is impressive when you consider the price comparison of devices costing 4 x as much as the Matterport.

    Indeed my experience is that the results are very accurate for my non building orientated needs, which I would suggest is more demanding as I have scanned several cars for modelling purposes and I have found the accuracy to be within mms.

     

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  • We tried several real world projects with various partners/professionals e.g. www.3dkad.de and www.mapindoor.de.

    We tried different scanners from NavVis, Faro and Artech (https://www.artec3d.com/news/makerspace-munich) and others yet not available on the market.

    Also we got various opinions and feedback from Autodesk HQ munich & Research Zurich (http://through-the-interface.typepad.com) in this field as also from friends in the AR/VR buiz like Ignyte (http://ignyte.de/portfolio/audi-le-mans-vr/).

    And no doubt comparing the costs, the result is ok for drafting and evaluation in small projects. But most AEC/BIM-projects are large scale and not a small living home - so the scan range is an essential criteria.

    So in our opinion it´s not ready for a rock solid professional AEC/BIM-workflow, where you need an accuracy of max. 3-4mm to avoid any troubles within a project.

    I am no pointcloud or CAD expert, but I guess I can trust the feedback we got from the related professionals. And yes - even if you use laser to capture there are many things you need to consider to get the needed result.

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  • I would recommend Danny as leading expert in this field: https://support.matterport.com/hc/en-us/profiles/14114135127-Danny-Basting

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  • Good info there.

    So yes small scale project accuracy is good, which is my area and the other small enclosed space examples is still good for Matterport usage.

    i still think accuracy/cost still compromises the value of LIDAR to small projects/companies at the moment.

    The next few years will be interesting if LIDAR can make it down to the Matterport rice point.

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  • Hello Ashley, 

    I am doing my first scan for the purpose of getting the best mesh and obj file posible. I was wondering if you could give me extra tips. I read that you recommend doing more scans than usual, do you have a specific number of scans for a space of about 100 m2 (1076 ft2).

    Thanks!

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  • Hey Carla,

    working as Uber for AEC companies and offering point cloud processing and scan to BIM modeling on-demand, this is my 2 cents.

    Disclaimer: the floor plan is needed to answer your question, as well as knowing what you will use this mesh for. The premises layout might be very tricky. The end-purpose might be different (furniture production, Revit model, etc) So without these questions answered, I believe you may get ONLY general recommendations here.

    The registration algorithm at Matterport uses both spatial data as well as RGB data for alignment. This means that lighting and movement in the capture area can kill your productivity.

    We were testing point clouds generated by NavVis trolley (Matterport uses the same technology) vs laser tape vs laser scanner. The results are the following. The maximum distance between scanning stations is 30m, the accuracy is +\- 20mm.

    To wrap up, in your case, I'd recommend using 20-25m as a maximum distance between the scanning stations. In the critical areas (where high precision is needed) reduce it to 10-15m.

     

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  • @Nick Bleschik

    Do you actually use a Matterport camera? There is no way you’ll get any registration of scans with 20 - 25 m spacing. You’re pushing it at  5 metres in good conditions so to generate decent quality with the Matterport I’d suggest  a minimum of 3m between scans and to really go for quality 1 to 2 metres.

    Word of warning you won’t get any point cloud data from black or very dark objects as they absorb the infr-red. 

    The .obj is very decimated model and doesn’t produce a good mesh model at all. So you need to request the scan cloud data as that is the raw data with much more information and points.

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