Lost in a maze of LiDAR

[Stevet]

Hi,

I've been trying to understand the relationships of LiDAR and Asciixyz and EsriAscii, raster surface creation and I'm just getting tied up in knots.

I have worked through the tutorials, (USA orientated) and they are excellent, however, Promap (whom we are about to buy data from) don't deliver lidar data as .las files, and although they have tried to be helpful in explaining how to insert the data, I still come up short on understanding, (and being able to deliver what my boss wants).

I just need an easy way to get point cloud data into a .dwg.

Basically, I want to have a 3d drawing that I can just put into a landscape and be able to view it from any angle and be able to say what the height of the land is at any given point.

I'm sure I've missed out lots of info that would be needed to make a meaningful answer, but feel this is turning into a novel, and I'm losing the will to live.....

Kind regards,

Steve

[Murph_map]

LiDAR is the process or type of files, like CAD files can be DWG or DNG or any number of file extension. There is a standard on creation the data that goes into the file but no required file format. It varies from the software/hardware that creates the file(s). The .las extension is just one that Autodesk partnered with. An ASCII xyz file is normally a standard text file you can open in any text editor (NotePad) The format can be as simple as 1, 1,1,1 tree- with the first charater being a key ID, the next 3 the coordinates (X Y Z) with the last part being a description of that point. Some of the files may have a few lines above the point data rows that may provide other infomation such as the datum/coordinate system, insertion point, scale, etc. The file extension vary again by the creater of the file. The EsriAscii (grid) file is a E$RI format that AutoCAD MAP3D can read with the Raster/Surface provider with Data Connect (FDO).

To use the ASCII XYZ file you need to use the MAPPOINTCLOUDMANAGER to load the files and create an index file (.isd) Same for a .las file. From there you can create a raster surface with the surface manager, (right click on the point cloud layer) Creating the surface will add it to the map and show it in the display manager.

The Raster Surface file(s) either created from the point cloud (default TIF) or EsriAscii already created is only usefull with the FDO raster/Surface provider. Along with a color assigned to a pixel it also has a elevation assigned to it. The raster engine, used with FDO, can read that elevation value and create the 3D modle. To use those rster surface once they are added to a map is to style them based on the elevation property (Heigth). Either one of the provide palettes or select the from and to colors of your choice. From there you can view it with any of the 3D viewing tools, orbit, named UCS & plan or the Nav cube.

[Murph_map]

FYI, the point clouds tools in Map3D, Civil 3D and Vanilla AutoCAD are three different animals and not interchangable other then the las/isd files they all can use those.

[Stevet]

Thanks Murph,

That was a great help, and I actual managed to create something today resembling a map with point data, I feel I have a long way to go yet but I'm getting there...

 

Just before I sign off, what did you mean when you mention the EsriAscii only being useful with the FDO raster/surface provider?

 

Kind regards,

Steve

[Murph_map]

Thanks Murph,

 

Just before I sign off, what did you mean when you mention the EsriAscii only being useful with the FDO raster/surface provider?

 

 

The FDO provider is the only way to add it to a map with 3rd party or custom routines. With the Acsii-xyz files there's a couple different ways to add data to a map.

[Stevet]

Thanks for that Murph

 

Kind regards,

Steve