Structure, canvas and SketchUp


#1

Anybody had any experience using the structure sensor and sketchup . https://canvas.io

If this works the way it’s portrayed then it sounds amazing - they do a scan to cad service - delivers back a .skp. This would massively speed up my surveys and existing model builds - the accuracy seems to be there.


Automatic Architectural Survey?
Upload a 3D scan flie
Working with Canvas Scanner Device
#2

Hi @bifterx! Alex from Occipital here — I’m the product manager for Canvas. So I’ve had quite a lot of experience with it :slight_smile:

What kind of questions/concerns do you have? I’d be happy to share more information here if I can be helpful.


#3

Hi Alex
Very interested in structure, canvas and whether I can fit it into my workflow. Surveys done currently with Leica Bluetooth laser and iffy companion app, then manually build the model. I guess I’m interested in the .skp output from the scan to card service. Could be a huge time saver, as well as being able to get on with the actual design process quicker for clients. Would be useful to see a sample output.


#4

Hi Alex, one of your colleagues, Scott had sent me a demo .skp output which looks nice and clean, obviously it’s a simple room and I understand it’s day 1 for the product but it would be useful to see something a little more complex. Am I right in understanding that the service strips out the clutter (furniture etc) to leave the bare room? It would be useful to see a grab of an original scan and then the cleaned output.
Cheers
Rob


#5

Definitely! Drop me a line at schiff@occipital.com and I can show you some before/afters. You are correct that the output strips out the clutter — our goal is that the CAD file you receive is the architectural shell of the space captured. No furniture or features that aren’t actually built in.


#6

@Alex: Great video.

As an architect I would like to know more about:

  • the accuracy. How accurate is the scan? Lets say I’m doing a scan of a house: 7x12m floorplan with several rooms, hallway, stairs etc. What should I expect? On the webpage it reads: 1% at 1m. But how much though at 5 to 10m? If it’s 1% - we’re talking 7 to 12cm’s here? Any way/tricks to improve that? Markers of the floor? Overlapping scans?
  • If I don’t have the time to wait for your CAD service, can I input the scan output myself in any ‘normal’ file format? DXF point data? - anything else?
  • is the texture data saved during the scan as well? Could be very useful so you don’t have to take photo’s.

I had my eye on the structure sensor (and Tango) from the beginning but I’m waiting the accuracy to be in 7 to 12 mm and not 7 to 12cm’s to consider using it…


#7

Hi Max! Great to hear from you.

There are a few ways to ensure the best possible global accuracy:

  • Make sure you’re using our Wide Vision Lens. This helps keep tracking stable and minimizes drift, especially on more sparse scenes.
  • Make sure your Structure Sensor and Wide Vision Lens are well-calibrated using our Calibrator app.
  • Make sure you make a complete loop around the room and overlap your starting point, and hit the “Enhance” button when it shows up. After your scan is uploaded, we actually reprocess it with more powerful algorithms, which further enhances the reconstruction.

With mobile 3D scanning, where you’re moving around the scene and we’re building a model as you go (vs. a stationary setup), it’s generally very difficult to give an absolute measurement tolerance because so much depends on the user. That said, most measurements that were checked against blueprints or tape measure during various pilots were within ~1%. Unsurprisingly, people that had been using Canvas longer typically got the best results (often better than 1%). I’m hoping to put together some more case studies on this - if you’re interested in helping, drop me a PM!

If you’re on a time crunch, you can always email the raw scan to yourself and start working with it immediately (not to mention get measurements on device). That said, the email is in OBJ format, which I wouldn’t recommend using with CAD programs. However, MeshLab is a free tool you can use to start getting measurements immediately.

Regarding texture, when you order a Scan To CAD conversion and it gets reprocessed, this also colorizes the model, and we send this back with your CAD file!

As always, please do feel free to PM me via the forums if you have questions, feedback, or just want to say hi.


#8

Hi Alex, thanks for the reply!

Still a few more questions if I may;

  • do you walk around while making a scan OR is it better to stand in the middle and just rotate?
  • how long does it take to make a scan of a room size just like in the video?
  • would it be possible to receive a raw obj scan for a room with some doors and windows (something like in the video) ?
  • with colorize - you mean just color or also photo imagery?
  • final question - I’m not a mac person nor do I use Ipads. Would it work just as well if it was connected to a windows tablet/notebook (for instance a Surface Pro or any lightweight modern laptop)?

Hoping you could shed some light onto this. I’m exited about the new scanning possibilities and anxious to replace the old tape and measure workflow with something more modern.


#9

No problem!

  1. Yes, you can walk around the room to capture details, behind furniture, etc. We’re building a 3D model in real-time as you move around the scene, tracking your location within that model.
  2. I did that scan personally in about 30-60 seconds.
  3. I meant a colorized model - we don’t offer any photo imagery of what was captured.
  4. Canvas is an iPad application, and we don’t currently have a Windows version under development - so you’d need at least an iPad to be able to use it. However, you can use the scan or the CAD files generated on Windows as there are many programs for both available.

Excited for you to be a part of this as well!


#10

Thanks for quick replies and the info @alexschiff . I’m tempted but the necessity to have to buy an Ipad that I have no other use for is making the decision a bit harder. Have to think about it…


#11

I think al the questions that I have been answered. I am interested. This kind of thing would be really great for my kind of work.

The only thing I would add is that I am slightly disappointed about is that textures are not applied to the model. I find things like where the electric sockets are in a room is really handy to know. I guess this is just limitation in the software, so it may be possible in future?

But yes, I am going to keep an eye on this - just slightly afraid to be among the first ones to have a go!


#12

I ordered my sensor last week, looks like it will be shipped towards the end of this week. Will let you know how it goes…


#13

What’s it like? Had a chance to test it out yet?


#14

nicely made bit of kit. I’ve got my first survey with it next week, it’s a listed building so will be pretty quirky, so a good test also 'cos I’ll be scanning a number of rooms I’ll let you know how all the rooms stitch together in SU after I get the cleaned up files back from the Scan to CAD service. Looking forward to it!


#15

Initial Thoughts

OK. Well. I carried out my first survey with Structure on Tuesday. It was a listed building and very quirky with odd split levels etc.

First Survey, so I wasn’t going all out to just use Structure as I am aware of its accuracy ‘limitations’ so I was using my usual Leica Disto and companion Sketch app to do my usual measure up and record.

I recorded all the major rooms with Structure (and Disto) as well as complicated areas where the scan was going to capture way more info than was going to so I could refer back to it later if reqd. (on a side note, the wide angle lens you get with the kit is an absolute godsend for taking photos in tight spaces;0)

So nearly did the whole thing on the first day (took a while as I was doing both) but had no problems with the capture software, just took a few goes to get the knack of doing a room - drawing curtains, avoiding mirrors, identifying a signature bit of furniture that you can use as reference.
Basically the Structure sensor is aligned with the iPad camera and a wide angle lens, so it captures through the IR lasers for depth and the RGB from the iPad camera. But. as you make a circuit the system can acquire drift, as you get back to a starting point, the system can recognise this and an ‘Enhance’ button appears which corrects for this drift - it works best if there is furniture and other items in the room that act as a signature that the system recognises a prior point but it doesn’t always work. But you can do as many scans as you like until you get one you are happy with.

So by the end of the first day I had done all of the internal rooms bar one and the exterior, so I arranged to revisit the next day to complete the survey. On my return did some standard measurements on the rear exterior and started on the last room. Now, Ive been using my Leica Disto and companion Sketch app for a couple years and recognise that the Sketch app is flaky at best and seems to get slightly more flaky with each iteration but when I got it there really wasn’t much if any competition available at a reasonable price so I stuck with it and its general crapness. Anyway while I was doing the last room, it started to get slow and not record gestures or input so I jumped out of the app, killed it and reopened it as per usual to give it a fresh start. Yep, lost everything from the previous days survey, kind of angry but the client was in the room so couldn’t swear too much.

Obviously I still had all the scans in Canvas so I had to go back through the house and do another measurement survey, in which, I didn’t record nearly as much as I did the previous day. I scanned pretty much everything and just took critical dimensions with my Disto.

Anyway, I UL’ the major rooms to the Scan to CAD service and I got back my first set of rooms this evening in .Skp format. I was a little apprehensive given I hadn’t used it before and I’d invested in the hardware etc but hey, its great to be pleasantly surprised and I was! the files came back nice and clean, layered (I need to re-layer them to fit my workflow) and the accuracy is definitely good enough as the rooms were represented correctly and I can adjust to fit my critical dimensions.

On the accuracy point, I went into this knowing what the score was, so If you are doing a room, the further away you are from the target, the lower the accuracy. From my initial checks this eve my accuracy ranged from with 10mm to around 50mm, this is inevitable as sometimes you just cant get close enough due to furniture items etc, Occipital say that you can expect an accuracy of about 0.14% at 400mm and 0.3% at 1m, my first time sort of bore this out (ish), if I was thinking about how I was scanning rather than just waving the thing about, I got much better results - bizarrely the accuracy is higher at the periphery rather than the centre of the scan, I’d love to know the technical reason behind this.

So as an initial gut feel I am very happy with the kit and the result as I have a bunch of rooms done that I can stick together in SU and use a base for the remainder of the model - it has saved me a TON of time as getting a detailed model up to scratch takes (me) a great deal of time and I can concentrate on the remodel design. (fun bit)

When I’ve got my other scans done and done more work in SU I’ll give a more detailed response.

Just as an aside - the Canvas app captures everything so its another source of survey data as well as measurement, photos, panoramas, video etc. It grabs 100% which you can go back into later and take a measurement within the app, so If you forget to take particular measurements (which happens to me all the time) - you can get a steer from the scan even if you haven’t had it converted to an .skp

So to wrap up. Pretty fantastic, sits in my workflow well, accuracy is definitely ‘good enough’ alongside other survey data , I just need more practice. Oh, the client thought it was amazing - she even got me to scan her dog!


#16

Hi Tommy, you actually do get a textured model back when you place a Scan To CAD order. We just don’t texture it on-device in Canvas - yet :wink:


#17

it has saved me a TON of time as getting a detailed model up to scratch takes (me) a great deal of time and I can concentrate on the remodel design. (fun bit)

This is exactly what I like to hear :slight_smile:

Thank you for sharing your Canvas experience with the community!


#18

Thanks for sharing the experience. Do report more experiences for future scans please. Especially if you see a way of increasing accuracy (1% is too much for me)


#19

Thanks for such a detailed report! I think it has made my mind up - I’m going to get one as soon as I have paid my tax at the end of this month!


#20

Hi Tommy, I don’t think you will be disappointed - it’s not a total replacement for a traditional survey but sits along-side it and sure speeds things up. It is a new technology and product but the guys at Occipital are very helpful and always respond.

BTW - if your scan captures sockets, they are on the model when you get it returned.