Scaling from Grid to Ground

[Anonymous]

Previousy in LDD when I had a project i needed to transfer from grid to ground I could simply create a block of everything. Scale the entire block from a mid point of the site, explode the block, run check points and done.

Now in C3D 2012 when I explode my block it changes my elevations too. Yikes!!!! Luckily I had a copule of points

elevations labled and I noticed the new "Feature" of scaling my elevations too. 

My site is 4,500' across and grid to ground changes it 0.32'

Is there a setting to change this behavior?

TIA,

Bo

[ToddRogers-WPM]

Check out the document I have attached...

[Anonymous]

A complicated solution for my simple problem.

Granted it does work. But in my 30+ years of

surveying messing with transformations and whatnot when importing points 

can be very problemmatic.

I like to leave a job on grid till i've got all the field work done.

When you topo over multiple days, different crews, it's easiest to wait till

it's done then move it around. Then for future field work I will localize

to the job by leaving a scale of 1to1 in the data collector. It's like a resection

with a total station and no fudging required.

I just want C3D not to scale the Z on my block.

Thanks,

Bo

[mathewkol · Accepted solution]

AutoCAD's scale command scales in all directions.  It shouldn't be surprizing that your points' Z gets scaled as well.  We were all just lucky that LDT didn't scale them.

Here's a way to scale points yet keep the Z.

http://www.civil4d.com/2009/10/scale-your-points-keep-the-elevations/ 

[Anonymous]

Sneaky, Sneaky. Perfect!!

Thanks,

Bo

[peterfunkautodesk]

Very nice way of doing this, but I don't like the idea of messing with the point file (and too much work). I made a new PZ point file format, by making a copying the format that I used to bring in the data and then setting the fields for Easting and Northing to "unused". Now you can reimport the file with the new format and the Easting and Northing are skipped and the Z will be reset and you don't have to touch the point files.

Cheers,

Peter Funk

Autodesk, Inc.

[mathewkol]

Even better Peter, thanks.  I'll maybe update my blog post.

[Anonymous]

Good idea. And I'll use it sometimes.

Normally when I do a field job I start on assumed (Autonomus GPS Reading)

After my inital work is done, I move the data to a STATIC GPS point i collected

while I was RTKing, adjust the Elev to the Static or something I collected during

the inital survey. So I'd have to create a new file any way.

Both are excellent workarounds!!

Thanks,

Robert

[Lisa_Pohlmeyer]

This is a great solution for points.  Do you have something up your sleeve for surfaces?  I have LiDAR surfaces (obviously on grid) that I sometimes want to see in my project data (which I receive from the surveyor on surface).  The same thing happens when I apply the project Combined Scale Factor (CSF), the elevations change.  My solution right now is to draw a two line segments, scale one of them by the CSF from a base point of 0,0.  I then move the surface that amount.

[tyronebk]

For surfaces you can create a block from the surface, scale the block, set the Z scale to 1, and finally explode the block. Remember to purge the block so you don't have an extra surface hidden in the drawing. If you look at the surface definition you will see something like "Transform (0.000,0.000,0.000)", but if you inspect the surface the XY is scaled but the elevations are unchanged. Unfortunately this does not work for cogo points though as the block will not explode if the XYZ scales are not all identical. I used to use workarounds like this one and one similar to Matt's but I ended up writing a few custom commands to transform C3D objects more efficiently.