search

heremaps / pptk

The Point Processing Toolkit (pptk) is a Python package for visualizing and processing 2-d/3-d point clouds.
https://heremaps.github.io/pptk
MIT License
610 stars 112 forks source link

Displaying details of Point Cloud #8

Open MakerMovement7 opened 5 years ago

MakerMovement7 commented 5 years ago

I have a point cloud that displays in the pptk.viewer(), however, I can't seem to zoom the camera to get close enough to see the data. The data is a point cloud of a road collected from lidar on a vehicle on that road, but whenever I view it in the viewer, it just comes out as what looks like a line (presumably the line of the dots that make the road), but I can't seem to zoom in to look at the details of the road. The lidar LAS file was converted to an X,Y,Z numpy array using liblas and lat, lon, alt values.

conlin-matt commented 5 years ago

Hi MarkerMovement7,

I know it's been a long time since you asked this question, but I just figured out how to solve this issue and figured I'd post in case anyone in the future stumbles upon this problem.

The issue is that your x and y values are in units of degrees, while you z values are in units of height (m or ft or whatever). You need to convert your x and y lat/lon values in degrees into the same units as your z values, i.e. you need to project your points into a coordinate reference system that does not use degrees (e.g. UTM). There are a number of ways to do this, and GIS forums online should help. I found it easiest to convert my x and y in lat/lon into UTM coordinates using the UTM package.

MakerMovement7 commented 5 years ago

Thank you for taking the time to write a response. I could not figure out why in the world every lidar viewer I was tried would end up looking the same way: zoomed out with a tiny line of dots. What the heck?!? Every time! Wow, so yes sir. That is extremely valuable information, thank you! Whew, it took a while to get an answer but man it feels good to get one. Sincerely,JamesSent via the Samsung Galaxy S7, an AT&T 4G LTE smartphone -------- Original message --------From: Matthew Conlin notifications@github.com Date: 5/21/19 10:22 AM (GMT-08:00) To: heremaps/pptk pptk@noreply.github.com Cc: MakerMovement7 jamesgreener2010@gmail.com, Author author@noreply.github.com Subject: Re: [heremaps/pptk] Displaying details of Point Cloud (#8) Hi MarkerMovement7, I know it's been a long time since you asked this question, but I just figured out how to solve this issue and figured I'd post in case anyone in the future stumbles upon this problem. The issue is that your x and y values are in units of degrees, while you z values are in units of height (m or ft or whatever). You need to convert your x and y lat/lon values in degrees into the same units as your z values, i.e. you need to project your points into a coordinate reference system that does not use degrees (e.g. UTM). There are a number of ways to do this, and GIS forums online should help. I found it easiest to convert my x and y in lat/lon into UTM coordinates using the UTM package.

—You are receiving this because you authored the thread.Reply to this email directly, view it on GitHub, or mute the thread. [ { "@context": "http://schema.org", "@type": "EmailMessage", "potentialAction": { "@type": "ViewAction", "target": "https://github.com/heremaps/pptk/issues/8?email_source=notifications\u0026email_token=AHYXSTYYPHMAQKG3X6ETGJ3PWQVXDA5CNFSM4GUQQ3T2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGODV4TH6Y#issuecomment-494482427", "url": "https://github.com/heremaps/pptk/issues/8?email_source=notifications\u0026email_token=AHYXSTYYPHMAQKG3X6ETGJ3PWQVXDA5CNFSM4GUQQ3T2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGODV4TH6Y#issuecomment-494482427", "name": "View Issue" }, "description": "View this Issue on GitHub", "publisher": { "@type": "Organization", "name": "GitHub", "url": "https://github.com" } } ]