Advantages of locating points on real Z?

[drwilson]

Does anyone know if the pros/cons, implications of the option of useing points on real Z vs. not?

I have them set to real Z but having come from land desktop/C3D, our surveyors are used to snapping to points & getting horizontal distances & DTM doesn't read the actual object elevation, it reads the attribute elevation. seems easy enough to me to modify your habits to query & draw 2D if that's what you want but.... I'm getting resitance.

[Dent Cermak]

Personally, the only time I bring in my points at their Z value is when I am building my surface. The rest of the time I am 2D. I get cranly whedn I cannot fillet or join lines because of Z values on the points.

[tstrickland]

I do everything in 3d. There have been a lot of situations when someone later wanted a topo, etc, for the site, or an adjoining site, and it's not much trouble to go ahead and do it.
Another thing I've seen, if you're doing total station work, and say you're set up on pnt 100 and backsite 101, but youre really on 101 and backsiting 100, it will check with 2d, but 3d will usually tell on it unless you're in very level country. I've seen crews do this more than once. It can be fixed, but it's aggravating.
Also if you plan to use control for future gps points you need the z.
There are probably more, but no more trouble than it is especially with rtk, I carry my zees.

[Dent Cermak]

I do everything in 3d. There have been a lot of situations when someone later wanted a topo, etc, for the site, or an adjoining site, and it's not much trouble to go ahead and do it.
Another thing I've seen, if you're doing total station work, and say you're set up on pnt 100 and backsite 101, but youre really on 101 and backsiting 100, it will check with 2d, but 3d will usually tell on it unless you're in very level country. I've seen crews do this more than once. It can be fixed, but it's aggravating.
Also if you plan to use control for future gps points you need the z.
There are probably more, but no more trouble than it is especially with rtk, I carry my zees.

I draw mainly with polylines. 3D polys are a pain. In reality all the 3D data is in a 2D drawing without all the problems with polys.
Sure you need to collect data x, y, z, but that really has nothing to do with the drawing. If you are going to use a point for GPS, don't you download that info from the *.crd file? If you think it's necessary to hand key in the x, y, z values then create a F2F setup that labels the x, y, z data for the control points in your drawing on a layer called "control".
You can run your backsight checks with the points on actual z value just fine. When you erase those points, that setting can go away. When you need 3DZ, use it, otherwise points not at actual z value are much easier to deal with and the whole system still functions correctly without any problems. I suppose that is why Carlson made it an option item.

[drwilson]

There are bits & pieces from all the software I've used in the past that I like. Having the points on a zero autocad elevation for the purpose of snapping too & drafting is nice. With Autodesk, surface modeling didn't work from the actual point object elevation within the drawing, it worked from the Z value in the point database, i.e. CRD.

[ColC]

I believe the intention of the real z's is to distinguish whether the point will be used in the contour/triang process. So the point can still have a z value but if the point is turned on duringthe Cont/Trian routine it will not be used in the DTM. I use it for locating the external walls of buildings which I need for a plan view only but also to provide an internal exclusion of contours. So my code for HSE produces a polyline which, if closed, provides for easy hatching but the code is not used in the construction of the dtm other than as an exclusion area.

The method which works best for me is to create two layers, a DTM layer for points to be used in the DTM process and the main layer of the object itself to enable the drawing to be constructed. So codes related to roads for example, I will put them into DTM_Road and then individually into RoadKb, RoadCr, RoadPath etc. and all spot levels go into another layer DTM and into NS.

Then when I wish to run Cont/Trian I just turn on DTM, DTM_Road and Building. Other layers may be turned on at my discretion. The DTM layers are then turned off drawing the process of drawing the plan. If a layer which has points, where real z's is not selected, is on at the time they will not be used in the DTM process.

When running the Cont/Trian check to see which entities are being used in the process on the last tab of the selection panel.

The power of the F2F is immense and there are many different ways to get the same result. I do have problems at times with lines and polylines which have different heights at the endpoints. If I inverse from a point to perpendicular to the line/polyline then it is right angles to a point along the line probably at the same z, but not in a 2D sense. I would like to see the inverse to be changed so that it only uses X,Ys

[tstrickland]

Maybe I misunderstood the question.
I carry my elevations with me when I survey, but don't draw 3d polylines or lines unless I'm doing contours or something that requires 3d.
Some guys ignore elevations when surveying, but no more time than it takes, I carry my elevations with me. What I do in the office depends on the job. For just plain old boundary surveys, I draw everything at 0 elevation. Anything else can be aggravating.

[drwilson]

Maybe I missunderstood my own question.

Is there a difference between the "locate on real Z" toggle in Point defaults vs. FLD file code settings? i.e. does locate on real Z work differently depending on if you bring points into the drawing with draw locate points vs. field to finish?

I'm bringing them in with draw locate points & either way that real z is set, triangulate routine appears to use the elevation values from the CRD regardless of the point block elevation.

I'm missing a piece of the puzzle here. what is the purpose of real Z?

I know why I don't want it. I want my snaps weather I'm drafting or measuring to default to zero horizontal elevations. But I want all my elevation information from points to be real.

What I'm familiar with is survey routines that use the external point database, i.e. CRD for elevation values/calculations/surfaces and objects within the drawing as 2d nodes for the sole purpose of horizontal location/node snaps

Turning true z off seems to do this. Am I missing something? What is the purpose of true z on?

[ColC]

My apologises, I was confusing "on real z" with "non surface" in F2F. My problem is I read the forum after breakfast on my notebook before going to work and without my PC to check the finer details. And some some times my ageing brain has not fully fired up at the time.

The "on real Z" has the same implication in both F2F and Draw Locate Points

[J-Mac]

I hate Real Z. It caused me a lot of problems when I first started using Carlson - 3D lines and skewed blocks, etc.

I don't see the reason for it, as a separate point file can be used for contouring data.

[ColC]

That is the beauty of Carlson software it caters for variety of users and the options are there to select the manner which suits. The more you explore you more you can customise.

[J-Mac]

Beauty? Sure, I guess - after you figure it all out. But having the default be points located on Real Z is a bad idea. It's especially bad, since it's located in two places, under the Points pull-down, and on F2F (Additional Draw Options).

I know now where these are, but the first job, trying to calc in the field, it was a mess.

[Dent Cermak]

Strange? Locate on real z is not the default on my Carlson Survey with embedded AutoCad. Is this an intellicad thing?
AND, if I select real z, the points come in that way; when I open a new drawing the "real z" box is not checked. In the original drawing ir stays set to what I last selected.

[J-Mac]

Hmmmm....don't remember now, with CS 2012 - just remember the first time using it, and on the last install that I did using CS 04 & 09, that the default was Real Z, in both Points and F2F.

Maybe it's been fixed on 2012.

Not talking about IntelliCad.

[drwilson]

I don't remeber what mine was default. I checked it on per someone elses advice & now I'm wondering why.

I use the point group option for adding points to the surface & it doesn't matter it the points are true Z or not when building surface that way so... I may try going back to true z off & see if the world ends.... I'll let you all know.

also using imbedded autocad 2012