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Exporting terrain mesh into landxml, possibly as a point cloud

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Message 1 of 21
tbranan
2009 Views, 20 Replies

Exporting terrain mesh into landxml, possibly as a point cloud

I already own 3d studio max, and Maya, and it seems neither can resolve my current issue. I have a peice of geographical terrain mesh that I've imported in from 3d studio max. its a fairly high polygon count, about 2.2 million. I'm trying to see if Civil 3d will do what I need. as far as I can tell, it will, but I haven't used autocad of any kind since about 1995. Things have obviously changed.

 

First problem is the mesh seems to have come in Y up instead of Z up, but thats not a dealbreaker although it'd be better if it didn't.

second is all the edges between vertices seem to have been bezied, or curved at the very least. The mesh is extremely unrespnsive even though it works fine in Max. again, this may be not too big a deal.

 

third, if posible, I need to create a point cloud from this, then export it to LandXML. I'm only using a trial version of civil 3d at the moment cause I need to see if it will actually do this or not before plunking down the money, and buying it would take like 5 weeks of beauracracy to get through. I've looked at the help files and I'm not finding the point cloud options where they say and exporting to LandXML doesn't seem like a quick file/export kind of option. And I can't find that where it says in the help file either..

 

I'm fully ready to call myself ignorant on all this, cause I am. My end result is to get this into 3d Analyst in ArcMap. Trying to figure out all the steps hasn't been easy. If someone could at least say its possible, that would be nice. If someone could say yes, its possible with what you have, and here is more or less how, that would be fantastic.

 

thanks to all

20 REPLIES 20
Message 2 of 21
antoniovinci
in reply to: tbranan

If your very last goal is a Landxml, you've only to explode that TIN up to 3Dfaces level, then you create an empty Civil surface, to which definition you add those 3Dfaces as "Drawing objects", finally _LANDXMLOUT. 

Message 3 of 21
tbranan
in reply to: antoniovinci

I don't think its actually considered a TIN at this point. its just a mesh I imported from 3d studio max. I've been searching the help and it keeps telling me to "go here to do x" and I go there and there is no x to be found.

 

it says there is a point cloud option in the create ground data panel, and there is no such panel. says there is a create point cloud data wizard and there is no wizard.

 

I look at a youtube video for how to export a landxml file and it shows me options I don't have or how to get there. Don't really understand why there isn't a simple file/export for it. I'm sure they have their reasons but I don't really get why importing a file is under 'insert' instead of just file/import.

 

I solved some of the other small issues but the big ones still remain and hitting my head on the desk is about as much help as always. its fun to be clueless.

Message 4 of 21
tbranan
in reply to: tbranan

 these options locked out because its in a trial period? seems like its supposed to be fully functioning. and if it is crippled, its an odd option to remove those.

 

even trying command line optons tells me they don't exist.

Message 5 of 21
Jeff_M
in reply to: tbranan

Nothing is locked out in the trial period. Are you using the correct shortcut to start C3D? What workspaces are available to you?

workspaces.png 

You will be wanting the one named Civil 3D. If it isn't available, then it sounds like the wrong shortcut was used to start C3D. The Create Point Cloud is on that Create Ground Data panel you see in the image above, you need to click the header of the panel to expand it and then you will see the command there.

 

The trial you have, is C3D2013?

Jeff_M, also a frequent Swamper
EESignature
Message 6 of 21
tbranan
in reply to: Jeff_M

thanks for making me double check that. aparently, if you look at the whole line on the first icon, its "civil3d AS autocad" and not just "civil 3d"

that was really helpful.

now, all the magical items have appeared, but after having taken a look at them, none of them seem to have an option to take my object and create either a TIN or a point cloud off of it, unless I'm just confused on terminology or method.

 

but its progress of a sort.

Message 7 of 21
AllenJessup
in reply to: tbranan

If you want to go through Civil 3D, you'll have to create a surface or a Point Cloud. You can't do that from a mesh. If you bring the mesh in to Civil 3D and explode it. You will have 3D Faces and can use those to create a surface. Be careful if the mesh has a base, you'll have to erase that.

 

If you want a Point Cloud. You'll have to use a file type that Civil can import. The image below shows a list of those file types.

 

AllenPCLD.png



Allen Jessup
Engineering Specialist / CAD Manager

Message 8 of 21
tbranan
in reply to: AllenJessup

1. ok, so explode mesh

 

2. ???

 

3. profit!

 

I think thats how it goes..

 

all kidding aside, I explode the mesh into faces, then how do I select those faces to create the point cloud/tin/etc ? poking through the options it didn't look clear how I would be able to grab items in scene to create results. it seemed to mostly want some kind of external file.

Message 9 of 21
AllenJessup
in reply to: tbranan

In the Toolspace, on the Prospector tab, right click on Surfaces and create a new Surface. Once it is created expand the Surface and the Definitions and right click on Drawing Objects. In the Add Points From Drawing Objects dialog box select an Object type of 3D Faces. Hit OK and select the 3D faces from the drawing. Once that is done a Surface based on those faces will immediately be build.

 

After that's built you can right click on the Surface and select Export to LandXML.

 

DOD.png

 

Allen



Allen Jessup
Engineering Specialist / CAD Manager

Message 10 of 21
Jeff_M
in reply to: tbranan

What are the objects created when the mesh is exploded? Hopefully either a 3DFace or a Polyface, as these are the 2 that can be used to define the surface.

 

Providing you have one of those, on the Create Ground Data Panel, select Surfaces, then choose Create Surface. Give it a name and a style to display, hit OK. On the Prospector, find the Surface you just created, expand the tree until you see the Definition branch, right-click on the Drawing Objects, then change the drop down list to display the 3d object type. Select the objects.

 

9-20-2012 1-50-51 PM.png

Jeff_M, also a frequent Swamper
EESignature
Message 11 of 21
tbranan
in reply to: Jeff_M

great, I will try that as soon as its done exploding, which looks like it may have to wait till morning, as its still chugging away at exploding 2.2 million faces.

 

thanks to everyone so far who's offered help and suggestions.

Message 12 of 21
antoniovinci
in reply to: tbranan


tbranan wrote:

great, I will try that as soon as its done exploding


Well, you were already told about that, exactly in the post #2 of this topic (09-20-2012 08:35 AM), then Allen&Jeff showed it graphically...

I only wonder whether your computer will be able to explode such a monster: now your mesh has 2.2 M triangles, but the number of resulting vertices will be 2-3x for sure.

Message 13 of 21
tbranan
in reply to: antoniovinci

you're right, I was. At the time I was struggling just to get the file imported properly, had even less of a clue what I was doing and was accidentally opening straight autocad instead of civil3d, so you'll forgive me if I missed it in all the other issues.

 

and even with 96 gigs of ram in that machine it crashed so now I break it up and try again

Message 14 of 21
antoniovinci
in reply to: tbranan


tbranan wrote:

and even with 96 gigs of ram in that machine it crashed


Whoa (!) you have almost more Ram than my hard disk capacity...

Now it's time to think of weekend, but if you don't handle it, share with us your original mesh (in .3DS format) and be sure that someone here will help you, sir.

Message 15 of 21
tbranan
in reply to: antoniovinci

yea, well, I have to use it to deal with a lot of really large datasets of many kinds. It defeinitely helps when it helps, so to speak. then there are times like this were its no better than 4 gigs. But I broke the model up into 8 pieces and that seemed to do the trick.

as far as I can tell I now have it broken up and into a surface and was just looking through the responses again to see how to turn it into a point cloud. If I can even get that far today I'd call it good. That too may need to be broken up, maybe, if ArcMap chokes on it too, but I'll worry about that when the time comes.

Message 16 of 21
tbranan
in reply to: tbranan

as an experiement I tried exporting the surface to a landxml file and was rewarded with a 1k file. so that didn't work.

forgive me if I'm blind, but looking through the options for point clouds, it looks mostly as if you can go from point cloud to surface, but not vice versa.

 

I closed and reopened the file and it the object still shows up in the prospector tab as a surface so I assume I got that part right, but who knows.

 

I looked through all the comments again to see if someone described it and didn't, so if it is there, I'm unfit for life.

Message 17 of 21
tbranan
in reply to: AllenJessup

Well, I'm getting nowhere. I did what appeared to be the correct thing. I had it on specific named layer, I did as suggested and added the exploded faces to the surface. The layer switches to 0. I can't seem to find any other indication that I've corrected added them into the surface.

My 2nd attempt to export to landxml by right clicking on the surface shows no option to export. the landxml button on the tabs up top doesnt' do anything when I press it.

when I was able to export, the file was 1k.

 

and I still can't figure out how to create a point cloud from this. More searching of help files hasn't revealed any more knowledge on my part. It all still seems to be mostly about creating surfaces from point clouds, not the other way around.

Message 18 of 21
AllenJessup
in reply to: tbranan


@tbranan wrote:

Well, I'm getting nowhere. I did what appeared to be the correct thing. I had it on specific named layer, I did as suggested and added the exploded faces to the surface. The layer switches to 0. I can't seem to find any other indication that I've corrected added them into the surface.



The layer issue may be tied to the Surface Style you're using. It may be set to NoDisplay. Don't worry too much about that if you're only using it to convert the data.

 

Lets step back and see where you're going with this. You want the date in ArcMap. I don't have ArcMap so I don't know what the best way to bring in the data. I don't know any way to Export a Point Cloud. If you have a good Surface you can export it as a LandXML or a DEM. If those files will work for you then you should be able to get what you want from C3D.

 

If you would. Please list the entities that result from exploding your mesh and confirm that they are 3DFaces. If they are you should be able to build a Surface with them. You can check what's in your Surface by rt clicking on the Surface Name in your Toolspace, Selecting Surface Properties, going to the Statistics tab and expanding General. That should show how many point are in your Surface and it's extents. If there are only a few, or 0, points you don't have a good surface.

 

Let us know what the entities list as and what the Statistics show.

 

stat.PNG

 

Allen



Allen Jessup
Engineering Specialist / CAD Manager

Message 19 of 21
tbranan
in reply to: AllenJessup

I was told a point cloud via LandXML would be the most viable option. Second to that would be just a surface, i suppose.

 

after attempting to add the 3d faces to the surface, it would ask me to use a window crossing to select them, then think about it for a bit, then be finished. I attempted right clicking on many things attempting to get some sort of confirmation that they were were they should be after that.

 

Unfortunately I'm in the middle of another ram intensive process and it doesn't look like its going to finish before I have to leave for the day and I won't be here monday, so I plan to double check everything first thing on tuesday.

I'm likely doing something simple and incorrect but if I try to load the file right now it may crash the other process so I'm forced to wait.

Message 20 of 21
AllenJessup
in reply to: tbranan

OK. Let us know then. Have a good weekend!

 

Allen



Allen Jessup
Engineering Specialist / CAD Manager

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