how to make profile cutaway in 3d in new version?

JSL

Hi, I'd like to try out the new profile cutaway in 3D feature, but I can't seem to get it to work.  I created a line, selected it, clicked GENERATE PATH PROFILE from the Analysis/Measurement prompt.  Then I brought up the Path Profile Settings, selected "Render single terrain cutaway," clicked OK, and nothing happened.  Am I missing something?

Thanks for any help...

JSL

I was also wondering at what scale the import to raster conversion was speeded up?
Below is an image of the area I was attempting to export, which is about 3.5 degrees latitude and 4 degrees longitude, and it generated the standard message about export requiring large number of data tiles and appearing to lock up.  The open files were a number of vector layers, a layer downloaded from the World Topo Map source.  I experimented with closing layers, and it's the Topo Map that's locking up the export, but that layer is also the one I'd like to have in the export.

Thanks for any help.

Mykle

The default export resolution will reflect the maximum available from the on-line source.  Suggest selecting a large value for an initial export to verify that it works, then reduce the value until the resolution is acceptable.  For example, using the World Topo Map source, the size of text on the topo map is a useful guide: too small a resolution results in too small text. 

It is often easier to save on-line sources to a local folder, then combine them for a final image.  That will also wean your layers from on-line sources and speed up redrawing.  I will usually choose an area larger than needed, just in case I need to include more area. 

JSL

Thanks for that information--may I ask what you mean by saving online sources to a local folder?  Do you export them to a particular format, or save them as a workspace?

Mykle

Use the Export option to save an area of interest to a file on your computer.  The file type will depend upon your data, like saving World Topo to a raster file.  Then you can load your file and turn off the on-line layer.  Again, I usually save an area larger than I plan to use, just so I have room to extend outside of my original work area if needed. 

As I mentioned before, specify the resolution of a raster layer to be a more useful value that does not require downloading full, high-resolution files, perhaps resulting in the message you have been seeing.  This can be an iterative process as you try to find a resolution that does what you need without resulting in a very large file. 

If you load your local files, then need to change the datum and/or projection, your local files can wind up rotated.  If you have saved a larger area than your working area, then you can crop without blank space appearing around the boundaries. 

When I start a project, I try to define the bounds of the work area, then download several on-line layers and save them to local files.  Elevation, topo maps, geologic maps, whatever.  When Global Mapper needs to reload your data after a zoom or pan or whatever, reloading from on-line sources can be slow.  If you have replaced them with locally saved files, it is a lot quicker to reload. 

A different example would be when you have one or more GeoPDF files.  Each one needs to be rasterized for display in Global Mapper.  Each one will need to be re-rasterized when you open a workspace.  So I will load them one at a time, then export the full image to a raster file.  Then load the raster files and remove the PDF and Global Mapper can work with them more easily. 

If you have a pile of raster images that need to be tiled in your display, then you can load the raster files and export your work area to one file.  That can speed display changes as well.  We are just trying to reduce the number of operations that Global Mapper requires to handle changes. 

Vector data can be more complex.  I usually export to CSV (points) or Simple ASCII (lines) that I can manipulate in a text editor or spreadsheet.  Very flexible.  Other data may need to be exported in shapefile format, but I don't have the tools to play with them.  I do export to KMZ for display in Google Earth, and some editing is more easily done in that program.  Again, I'm saving on-line data to local files to speed and simplify loading. 

JSL

Thanks for that information.  I've tried various resolutions, but with the dimensions of the areas I'm interested in, there seems to be a quantum effect between unusable resolution and resolution that locks up the export.  I was hoping the update might help with my work, but it looks like the areas are just too big.  I'll go back to what I've done before, which is to wait until the project's finalized and experiment between Capturing the Screen Image or making a PDF, to see which produces the most acceptable product in the least amount of time.

Thanks again for the input.

JSL

Still need help with my original question, which is how to generate the cutaway profile view in 3D

JeffH@BMG

Hi JSL,

Just a suggestion -- it might be better to ask separate questions in separate forum topics, just to keep separate issues, well, separate (and less confusing to other users).

Anyways, regarding the 3D path profile question: it should just work, if I read your workflow correctly. Load some elevation data, then either use the Path Profile tool to define a line, or select an existing line and apply "GENERATE PATH PROFILE ..." to it, and the 3D view (if it's open) should adjust automatically. The one thing that might be confusing is that -- due to the way that we implement the 3D cutaway -- we can only do planar cutaways, either 1-way (along the path) or 4-way (along the path corridor edges). Because of this, we only use the first two points of the path line. So if you are using a line with its first two points close together, you may get confusing results.

So I'd suggest using the path profile tool in the toolbar, and defining a path by first left clicking in your DEM, and then moving to a new point, and right-clicking to finish the path. If that works, then your problem may be related to the line you're using.

Please let us know if this helps or not.

Best regards,

~Jeff

JSL

Thanks, Jeff, point well taken--I'll keep questions separate in the future.