LiDAR Scanning and RC Newbie Questions

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Hey all,

  Most of my work is pretty complex scenes for VR (large outside flowing into inside spaces like museums or art galleries) that leans more on the VR experience than archival 3d scans.  I’ve got a potential client that may be hoping for some volumetric measuring or will need me to render an unfriendly photogrammetry scene that a LiDAR scanner would help with, so I’m thinking of renting one for a bit if needed.  

 Background here is that I have not used a professional LiDAR scanner (Faro/Leica/etc) but am pretty familiar with RC.  I was hoping anyone who had experience with integrating LiDAR scans into the work flow could give me some advice by answering some questions (some of which may be so off base that they are unanswerable):

 - From the forums, it seems Faro line fits into the workflow pretty easily and one can get good results from an X330 or X130 which seem the easiest to rent.  How easy are these to use?  There seems to be a good paper trail on the Interwebs on how to operate them and enough in the RC forums/etc for the workflow and file formats.  

-  I know there is a thread or two of comparing RC and RC+LiDAR but they are few and far between - anyone care to illuminate how much better the LiDAR combination is if accuracy ISN’T a priority (how good the final model looks or how much time it saves you in post 3d-modeling) ?  How much more or less time does it add to a photogrammetry reconstruction (scan, render, put some hours in 3d remodeling, etc.) workflow?

-  For a large space (say a 20 x 20 foot room scattered with some stuff) how much of a difference would you get from a photogrammetry only scan and a LiDAR scan for volumetric reading and other measurements?  I know there are a million variables here, but I’m wondering for an internal 20x20 room, are we off by cms, inches or feet if we had to guess?

   Again, I know these questions have a million unknowns, I’m just trying to gauge if I need to rent one of these things for a month or a week before I become confident that I’ve got good data from the scanner for my RC reconstructions.

 

   Thanks!

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first thing, you need to do registration in other software. and import them all as exact.

rc won’t do a very good job aligning them.

it basically turns all scan locations into a cube map. and therefore you need to export each scan location as a ptx or e57.

if you want good textures, you’ll probably still be taking just as many photos as normal.

as which point you’d get a decent model anyway. but laserscan dose improve it a bit.

and it dose give different results while dealing with glass etc…  

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My advice is very short:

If you haven’t used a scanner before and you need the project to work right away, hire someone to do the scan for you!

It’s a huge field in itself and would take quite a while to master, especially if you’re self-taught. It will be better, quicker and cheaper!  :wink:

 

@ chris:

Hhow does laserscanning give different (I assume better?) results than photogrametry?

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Thanks everyone!  Love to hear more about it…

Gotz, you’re probably right, but my hope is if my client needs it, I may not need to rent one as an architectural company may have one I can futz around with on the project in my free time - if the timing is tight and they need it fast I’ll probably have to go with getting a small company or person to do it for me…

 Oh and as for the question of what differences, there is this thread from about 2 years ago…

https://support.capturingreality.com/hc/en-us/community/posts/115000778231-PTX-Photos

Couple of photos, but this one speaks the most to me:

https://www.capturingreality.com/forum/download/file.php?id=31

The detail that the LiDAR picked up, depending on how much time it adds to the shoot, may be worth it for some bigger projects if I land them in the future.  I’m trying to figure out if I’d be spending more time in post (Modo/Z-brush) cleaning up something like that stairway and door or if the LiDAR scans would pick them up for me.  As discussed in that thread it seems to destroy reflective objects, but those are easier to fix than something like a stair reconstruction…

 

 

 

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Castlenock, that sounds good - if you can get your hands on one for naught and have some time at your disposal to get to know it, then why not? All just a matter of experience, no magic involved…  :slight_smile:

To be honest, I didn’t quite follow the argument or rather which is better when. It very much seems to me that Jon shot the images already knowing he has a scan to back it all up. From my experience it should have been possible to get the same results using photogrammetry only.

What I didn’t get is about the glass or reflective surfaces, because I thought that in those cases both methods are equally flawed. If there’s clean glass, the laser will got right through and if it’s a reflective surface, it won’t work either. Same for photogrammetry but for different reasons, only that with reflective surfaces, photogrammetry might at least get some rought outline of the geometry, if there is enough detail on the surface (like scratches) so that it can latch on to something.

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BTW, Castlenock, are you the author of this article?

https://developer.valvesoftware.com/wiki/SteamVR/Environments/Advanced_Indoors_Photogrammetry

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Gotz,

 

  I wish; that’s a Valve employee (I think) that has given me some help.  I’ve definitely copied/learned/altered that workflow for my own work…  I’m very happy with my shooting results, but still have a lot to go for getting faster in Modo/Zbrush - that’s stuff for larger projects I will be partly contracting out as while I think anyone can learn it, people like myself take 5 times longer than an experienced 3D modelling person.  

   I’ve studied those articles pretty intently, so I may be able to add some insight if you’re trying to follow them as well.

    The Valve offices are a good example of what I’m trying to do, it has a lot of stuff that people normally wouldn’t scan - most of the large VR scenes seem to really lean on environments that scan well (textured walls and floors, etc.) while most of my R&D has been scanning the more typical/glossy environments but more post work than your average scan.  

   If this contract lands, I may need LiDAR for specific volumetric measurements, but I’m curious to see if the combination means I can skip some more post work in the complex environments.  For example, chairs almost always suck in a photog scan and I’ve scanned a few traditional classrooms; I may take a single chair, scan the hell out of it, and then copy/paste it 50 times into a classroom scene so the bottom half of the chairs (under tables, etc.) don’t look messy and the results are o.k.   But some places have 8 different types of chairs arranged differently (those chairs with a rotating elbow desk for example) and I wonder if a LiDAR combination would take total time off my reconstruction - spend 10 hours in Modo or 3 hours with a LiDAR scanner?  

 

  If it’s the latter and I start getting some solid business (fingers crossed but a lot has to align…) I’d consider purchasing one and putting it completely in my workflow.

 

  I don’t use ***** at all, part of my gig is rapid scanning and prototyping, and since RC beats the pants off of PS in speed, I’m almost exclusively using that regardless of the built in volumetric readings, etc.

 

   My guess is for this project I scan a few rooms in a large building, render overnight, send to architect firms on Destinations privately so they can walk the space and talk about restoration plans with the buyer in VR, make their decisions, and rinse and repeat until the project finishes.   Should be fun if I land it.  

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Ah, sorry - I thought I’ve seen you posting screenshots. I guess I’ve read in too many for… what’s the plural? fori? lately…

I probably confused them with similar stuff you posted?

Anyway, I was just curious mainly. I agree that one can learn anything but it’s also good to know when to involve more experienced hands - if one has any at ones disposal…  :slight_smile:

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Hey Castlenock,

that sounds like an awesome project opportunity!

I guess we’re not talking about terraced housing or appartment buildings here, right?  :slight_smile:

Have you thought about getting a reasonably priced handheld scanner for your furniture? Because that would be much more efficient than using a classic lidar since you would need at least two handfuls of stations around the chair and then you need to align them and all that. The handheld will do all that for you…

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Sorry to bring up this old thread again but Castle I was wondering if you can help me with my UV workflow and remodelling like set out in that Valve interior example?

I cant for the life of me understand how to use the RC generated UV’s in Something like Modo with say 5 different textures created in my model…

Also in modo how to you import your model? do you change anything with regard to meters/centimeters?

I mean I can model fine in Modo but even when I have 2 meshes created for a low poly vs high poly original I am not sure how I create a material for the low poly model I created for walls etc and how to create UV maps for either…

Can you help walk through the process around recreating UV’s for the low poly and high poly models. RC seems to not like when I redo UV maps in Modo. Also Im not getting “new material” when I reimport back in like the example explains for Valve.

Help me Obiwan Kenobi, you’re my only hope.

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May the force be with you!  :slight_smile: