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BrianHailey
Posts: 2,716
Registered: ‎04-27-2005
Message 11 of 20 (639 Views)

Re: Query point cloud boundary then add all the points whtin the boundary

11-12-2012 10:31 PM in reply to: Neilw

That's the only way I know of to do it as well. Problem is, if you have a .las file, you can't add that to your surface as a point file. There's probably some sort of file converter out there that could get it in a usable format though.

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wang890
Posts: 798
Registered: ‎06-08-2007
Message 12 of 20 (635 Views)

Re: Query point cloud boundary then add all the points whtin the boundary

11-12-2012 11:49 PM in reply to: BrianHailey

we have both las and xyz.

 

the problem is total 5 billion points covering about 2km x 320km.

 

so i need at least 200m wide. length is the same.

 

which still makes it 500 million points. i just spent a few hours on my fast machine and found out that even for this computer limit is 10 million. it's not out of memory. just when rebuilding it will be fatal error. so i had to make the surface into 2. about 5 million per surface. and points is still 5-15m apart. there is no way due to software limitation i can get the true fidelity because those points are around 0.1 to 0.5m. we have to admit it, that the survey crew set the machine to too fine a interval. i prefer to have set something like 1-5m which is much more manageable for consultants. i heard some GIS program are much more powerful. would be nice to use those in conjunction which is like just get that program to export smaller point files covering say around the alignment and then just import for each exercise based on alignment left and offsets, say 100m each side. it's not going to make too much difference on the volume calculation once the surface is dense enough like now. before i had like 40m points those are no good. now i increased the number of points by 5-7 times. good enough what do you guys think?

 

this is the longest road project i ever worked. before even mountain high like sea to sky highway we were only doing 5-10 km and surface is 1m points surveyed properly by lidar. that was smooth also was using LDD at the time.

 

nothing this size. super stressful job i did all the road design and most of the drafting plan profile by myself. took me 2 months. over 300km long road with over 1400 horizontal curves and vertical curves in crapp north canada area. the ground looks like another planet.

Civil 3D 2012
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Neilw
Posts: 2,109
Registered: ‎09-04-2006
Message 13 of 20 (628 Views)

Re: Query point cloud boundary then add all the points whtin the boundary

11-13-2012 06:43 AM in reply to: wang890

With that much data you really need a robust decimation tool. It will cost you a little but it should pay for itself in a short while.

 

Try a web search for point cloud tools.

Neil Wilson (a.k.a. neilw)
Infrastructure Suite/C3D 2013, LDT 2004, Power Civil v8i SS1
WIN 7 64 PRO
HP Pavillion h8xt, i7 2600, 12 GB
RADEON 6450, 1 GB
http://www.sec-landmgt.com
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Posts: 247
Registered: ‎10-31-2006
Message 14 of 20 (618 Views)

Re: Query point cloud boundary then add all the points whtin the boundary

11-13-2012 08:00 AM in reply to: BrianHailey

There is a converter.  We use FME from Safe Software to convert lidar data files to xyz files.   It will let you extract points based on clipping boundaries and lidar classifications.  The resulting ASCII file can then be imported directly into the surface model, without having to use point clouds in Civil 3D.

David Zavislan, P.E. | CAD Manager / Associate | NV5 | www.nv5.com
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wang890
Posts: 798
Registered: ‎06-08-2007
Message 15 of 20 (601 Views)

Re: Query point cloud boundary then add all the points whtin the boundary

11-13-2012 08:39 PM in reply to: david.zavislan

thanks everybody for your input.

 

i did a 13km comparison on the volume from point clouds after many "add points to surface" runs and end up like 5m average points spacing. about 1 million points / 10km x 2km surface. compared to the 0.5m contours from some GIS program surveyor used to generate these contours which considered every single point i think. volume difference is 0.15%. now that's enough to convince geotech that there is NO difference on accuracy. before compared only 1km every 50m with a not so dense point cloud surface and difference is like 10-15%. i guess from statistical point of view more sample represent more accurate result. i told them in the first place when you look at the thing as a whole won't make any difference.

Civil 3D 2012
Work: Xeon W3503, 12GB, Quadro 2000, Yamakasi Sparta 301 + Dell PH2211
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wang890
Posts: 798
Registered: ‎06-08-2007
Message 16 of 20 (584 Views)

Re: Query point cloud boundary then add all the points whtin the boundary

11-14-2012 02:14 PM in reply to: wang890

i created another point cloud data base only on 50km long surface x 2km and set density to 100% but now come when i draw a box of 6km x 6km and ask it to add points and only give me 120k points? total real points is 60 million. what is controlling that number?

 

would be nice just to have a function like add points to surface and use selectible number of points. 1 million, 5 million, etc.

 

i have nother area when i use same box and it gives 600k points that's decent.

 

also when you make another box differently slightly does the software will add different points? makes sense each boundary you pick if the next one is the same location perfectly on 4 corners will produce the same points. are those points selected by random or software use stastics to calculate which point to add?

Civil 3D 2012
Work: Xeon W3503, 12GB, Quadro 2000, Yamakasi Sparta 301 + Dell PH2211
Home: 3930k, 12GB, GTX 590, U3011, QX2710
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Neilw
Posts: 2,109
Registered: ‎09-04-2006
Message 17 of 20 (581 Views)

Re: Query point cloud boundary then add all the points whtin the boundary

11-14-2012 02:29 PM in reply to: wang890

i created another point cloud data base only on 50km long surface x 2km and set density to 100% but now come when i draw a box of 6km x 6km and ask it to add points and only give me 120k points? total real points is 60 million. what is controlling that number?

 

See the link in my reply on 11/12. Thus the recommendations in this thread to not use point clouds for surface models.

Neil Wilson (a.k.a. neilw)
Infrastructure Suite/C3D 2013, LDT 2004, Power Civil v8i SS1
WIN 7 64 PRO
HP Pavillion h8xt, i7 2600, 12 GB
RADEON 6450, 1 GB
http://www.sec-landmgt.com
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wang890
Posts: 798
Registered: ‎06-08-2007
Message 18 of 20 (575 Views)

Re: Query point cloud boundary then add all the points whtin the boundary

11-14-2012 04:04 PM in reply to: Neilw

hi Neil

 

i think i found a better solution. it's a "trick"

 

i noticed this by accident. my last post when i said it's not giving enough points? that point cloud is the original one which used LAS.

 

what i did is i made another drawing, and then i create a new point group from the .isd file. with this point cloud, it behaves differently. i am able to add 1 million points each run. problem solved. still not 100% but much better than doing 100k points at a time.

Civil 3D 2012
Work: Xeon W3503, 12GB, Quadro 2000, Yamakasi Sparta 301 + Dell PH2211
Home: 3930k, 12GB, GTX 590, U3011, QX2710
*Expert Elite*
Neilw
Posts: 2,109
Registered: ‎09-04-2006
Message 19 of 20 (571 Views)

Re: Query point cloud boundary then add all the points whtin the boundary

11-14-2012 04:15 PM in reply to: wang890

what i did is i made another drawing, and then i create a new point group from the .isd file

 

What does this mean "i create a new point group"? Are you creating Civil 3D points?

 

It would be helpful to know why there is a difference when you use the .isd file. Can you verify that it contains the same data?

Neil Wilson (a.k.a. neilw)
Infrastructure Suite/C3D 2013, LDT 2004, Power Civil v8i SS1
WIN 7 64 PRO
HP Pavillion h8xt, i7 2600, 12 GB
RADEON 6450, 1 GB
http://www.sec-landmgt.com
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wang890
Posts: 798
Registered: ‎06-08-2007
Message 20 of 20 (565 Views)

Re: Query point cloud boundary then add all the points whtin the boundary

11-14-2012 11:16 PM in reply to: BrianHailey

a new point cloud object i mean. in the new one use isd instead of browsing all the LAS again. 

 

that point cloud from isd file somehow if you look at the property has a "displayed points" much larger than the one created from LAS. i am not sure why but worked for me. 

 

i didn't need to create the boxes for add points to surface so small that i have to do many times. 

 

try it out and see. take an isd file and make a surface even you use the from point cloud extent it will give you around 1 million. but the las point group one will give like 100k. something to do with bug 

Civil 3D 2012
Work: Xeon W3503, 12GB, Quadro 2000, Yamakasi Sparta 301 + Dell PH2211
Home: 3930k, 12GB, GTX 590, U3011, QX2710

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