Nomad point cloud import queries

[Andrew Lees]

I am new to Vectorworks and this is my first attempt to use point clouds captured with Nomad. Now, my scan of this floor plan seems to be a bit of mash-up, but that is not my main issue right now. I have seen a VW video on this (https://www.youtube.com/watch?v=_cQv1da242Q) and the point cloud model shown in that seems to behave somewhat differently than mine. In the video the presenter is able to zoom in and trace the point cloud - which looks great. When I zoom in however I get two problems:

 

1. The density of the point cloud seems to decrease - to the point of it being too vague to find hard edges to trace once I get close.
2. I have a grid pattern superimposed over my point cloud. The size of this grid (which is manifest as gaps in the point cloud) gets denser and more obscuring the more I zoom in.

 

The attached images show progressive zoom-ins as described above. This is an orthogonal top view (not plan view) with section box cutting the horizontal slice. For info, the point cloud was imported at 100% points resolution.

 

Suggestions?

 

Thanks

[michaelk]

@Andrew Lees

 

This is what I've found to make point clouds from Nomad work successfully.

 

1.  Use a recent, pro version of the iPhone to get better LIDAR.

 

2.  Smaller scans.  Only do one room at a time.  Maybe two if they are small.  The issue is drift.  The larger the area of scan the more likely that it will "drift" a little.   That's why you are seeing some walls duplicated on a different axis.  

 

3.  I like to scan around the other side of connecting wall openings to get wall thickness and to help line up adjacent scans.  It's important to always have objects or architectural features that will appear in at least one other scan to help line them up later.

 

4.  Watch the screen as you are scanning.  There is a slider on the bottom of the screen.  It only controls pass through from the camera to the screen while scanning.  It has nothing to do with what gets recorded (AFAIK).  Try turning it way down so you are seeing primarily or only the points that are being recorded.  Sometimes you will see a "jump" happen while recording.  I can't prove it but I think that's the scan losing its place.  Discard that scan and start over.

 

5.  In the VW drawing, lay out all the rooms from individual scans.  It takes a little while to rotate them all to the same direction.  I've found that if you use the _VW.pts version of the file, the floors will be level, but not necessarily at Z=0.  But they appear to be close to the same - usually negative - Z value.  If you've got one scan of a hallway, then it's easier to align the scans of the rooms off the hallway using the door openings.  If you keep each scan on a separate layer it makes it easier to work with and you are less likely to select the wrong scan by accident.

 

7.  When you have all your room scans laid out, use the clip cube to cut the top and bottom so you only have a sliver showing about 3 or 4 feet above the floor.  Try looking at it in top/plan view as well as top view in shaded rendering to see what shows up better for you.  That will give you a floor plan that looks like all the wall lines are about 5/8" thick.  You sort of have to draw it not too zoomed in.  The closer you get the more you see the spaces between the points.  You will quickly find the sweet spot.

 

8.  Once you draw your walls, guess at window and door sizes and locations.  Select one wall, turn on the clip cube and set the visibility to wireframe.  Now it's really fast to use the new drag handles on doors and windows align them with then scans.

 

9.  It also works outside.  I've had pretty good success using it to get eave overhangs, roof pitches, hardscapes, external columns, existing tree sizes and locations.  About half the time on a building the size you are working on it will hold together long enough to scan the exterior of the entire residence well enough to get an accurate footprint.

 

I haven't tried this yet, but I've heard that using a tripod for your iPhone that rotates around 360 and scanning several times in the same room produces better results.

 

 

[Tom W.]

7 hours ago, Andrew Lees said:

I have a grid pattern superimposed over my point cloud. The size of this grid (which is manifest as gaps in the point cloud) gets denser and more obscuring the more I zoom in.

 

I have not seen this before + have no idea what's caused it...

 

7 hours ago, michaelk said:

I've found that if you use the _VW.pts version of the file, the floors will be level, but not necessarily at Z=0.

 

Yes. Nomad generates a 'xxxxxxxxxxxxxxxxx.pts' version of the point cloud which is designed to be viewed on Nomad (because it is oriented correctly) + a  'xxxxxxxxxxxxxxxxx_VW.pts' version which is the one you are meant to import into VW (which is upended when viewed on Nomad). Make sure you name your scans + save them to a dedicated folder as you create them as it's a nightmare trying to find the files you just created otherwise! (the names Nomad gives them are completely random + they can't be arranged in date-created order... And for the life of me I can't see how you rename them or move them into new folders after the fact!! That could be me though...)

[Andrew Lees]

Thanks @michaelk some good tips there. I think shaded view makes it a little more punchy. I definitely will do it room by room next time. I can also imagine that a tripod would make it much better - kind of more like a proper fixed point cloud device. The Nomad instructions just said start it up and walk around - so that is what I did.

@Tom W. I was hoping that the weird tartan pattern was something easily fixed - like a grid setting I don't know about that can just be toggled off. As I said, I'm new to VW so what is obvious to seasoned users might be completely unknown to me. 

 

It seems a little more useable now though, so I will persevere and see if I can translate this into a serviceable plan. 

[zoomer]

11 hours ago, Tom W. said:

I have not seen this before + have no idea what's caused it...

 

I assume a GPU or GPU driver issue ?

 

 

19 hours ago, Andrew Lees said:

my scan of this "floor plan" ....

 

I only tried to scan more than one room at a time with Room Plan Mode

and was disappointed. I do not understand why it lost the angle.

All Walls should have been perpendicular but Room Plan was about 15° off.

I think Nomad needs more artificial or better human intelligence.

 

 

18 hours ago, michaelk said:

This is what I've found to make point clouds from Nomad work successfully.

 

This is all great @michaelk

 

 

18 hours ago, michaelk said:

There is a slider on the bottom of the screen.  It only controls pass through from the camera to the screen while scanning.

 

That was new to me.

 

18 hours ago, michaelk said:

It takes a little while to rotate them all to the same direction.

 

It does.

 

But I do not get where Nomad takes the angle from.

It is neither true north angle nor did I find any possibility to control this

in any way, like starting perpendicular to a Wall.

 

18 hours ago, michaelk said:

but I've heard that using a tripod for your iPhone that rotates around 360 and scanning several times in the same room produces better results.

 

I already tried to mimic that manually but did not find any benefit.

 

 

18 hours ago, michaelk said:

the floors will be level, but not necessarily at Z=0.  But they appear to be close to the same - usually negative - Z value.

 

I assume negative floor height level comes from iPhone to Floor distance (?)

 

 

18 hours ago, michaelk said:

5.  In the VW drawing, .....

 

7.  When you have all your room scans laid out ....

 

Looks like you made a secret from the most important 6. point ......

[michaelk]

36 minutes ago, zoomer said:

Looks like you made a secret from the most important 6. point ......

 

🤣

 

6.  Enjoy not spending an entire day measuring a building knowing that you will miss getting at least one (but probably more) critical measurements. 

 

Nomad point clouds aren't perfect, but they are way better than trying to read hand written measurements off of a crowded, incorrect old drawing two weeks after you measured the building 🙂 

[michaelk]

41 minutes ago, zoomer said:

I only tried to scan more than one room at a time with Room Plan Mode

and was disappointed. I do not understand why it lost the angle.

All Walls should have been perpendicular but Room Plan was about 15° off.

I think Nomad needs more artificial or better human intelligence.

 

I agree about room plan.  It can get confused by soffits, vaulted ceilings, timber frame roof trusses, etc.  

 

With point clouds you can usually get a reasonable slope to a vaulted ceiling, number and approximate size of beams, placement of HVAC supplies, light switches, wall thickness, difference in elevation between floors, etc.  Not perfect.  But so so so much better than spending a day with two people and a tape measure.

[zoomer]

49 minutes ago, michaelk said:

6.  Enjoy not spending an entire day measuring a building knowing that you will miss getting at least one (but probably more) critical measurements. 

 

 

That was my manual measuring experience so far too.

I always hoped Lidar Scans would prevent this.