How to get Cogo point to inherit elevation of an object via snapping to it.

[AleCVx]

Hi all Civil 3d veterans, I'm trying to resolve an issue that has been on-going for quite some time and I appreciate any help. 

I'm working with point cloud data and I frequently have to snap to a point cloud to get its X,Y,Z values. 

So far, I have been using the default AutoCAD point creation tool (with 3D snap enabled) to  snap to a point cloud, the Autocad point inherits X,Y,Z values of the point cloud. I then convert the Autocad points to Cogo points. 

Here's my frustration, It's quite tiresome to perform this simple task a hundred times a day. So I was thinking of creating an ActionMacro to speed up this task. 

What I want is to create an ActionMacro that allows me to snap an Autocad point to a point cloud and then automatically converts the Autocad Point to a Cogo point - which would have X,Y,Z values of the point cloud.

I recorded the Action of me creating the Autocad point by snapping to a point cloud. There after, I convert the Autocad point to Cogo point, which prompted me to 'select Autocad points' for the conversion. I selected the Autocad point and finished conversion.  I then stopped the recording. 

In the recorded ActionMacro, under the 'Autocad point creation' step, I changed it to 'Pause for User Input' so that I can re-use this macro to create Autocad points in other positions.

Here lies my issue. During the 'Autocad Point to Cogo point conversion' step, I recorded my action manually selecting a specific Autocad point earlier - so when replaying the ActionMacro, it would try to reselect that same point for the conversion. I could update this step to 'Pause for User Input' which would allows me to manually click and select a new/different point for the conversion. Doing so would defeat the purpose of having the ActionMacro in the first to speed up the task. 

From my understanding, the Cogo point creation tool doesn't inherit the elevation of an object via snapping. It would prompt me to enter the elevation value which isn't possible to know without creating the Autocad point first. Why is there no option for Cogo point to inherit the Z value of a snapping object? this feature is available for the default Autocad Point. I'm baffled by this design choice.

I have tried to get around the issue (in the ActionMacro) by putting the Autocad point in its own layer, and when i'm being prompted to 'Select Autocad Points' for Cogo conversion, I thought I could then use Qselect command to select the layer of the Autocad points to speed things up. To my surprise, when in 'Select Autocad Points' mode, I can't use Qselect to select the layer, I can only do manual selection by clicking on the point or use the fence selection tool. Another strange design choice. 

It would be great if we could just snap a Cogo point to a point cloud and inherits its  X,Y,Z values, then I wouldn't be going through so much trouble finding a solution to this issue. 

Thankyou everyone for your time. I apologise for this lengthy post and I appreciate your help. 

[Jeew-m]

How about this.

First, create a surface from the point cloud.

Then create cogo points on the surface using create points on surface.

It will automatically inherit the elevations from the surface. In other words from points cloud.

[Udo_Huebner · Accepted solution]

Command : CREATEPOINTMANUAL

Points Creation >Prompt For Elevations >  Manual

does what you want.

Click (snap) a point of the point cloud and simply press an additional <Enter> when the current point elevation is displayed.

You can speed up the task using this lisp macro:

(defun C:UhCreatePointManual3D ( / pt) 
;Points Creation >Prompt For Elevations > Manual
; Udo Huebner for Autodesk forum
(prompt "UH CreatePointManual with Z Elevation")
(while (setq pt (getpoint "\nPick a Point: "))
  (command-s  "-CreatePointManual" pt "" "")
)
(princ)
)

[AleCVx]

Thankyou everyone for the speedy replies.

@Udo_Huebner , I tried out your script and it works!! that's exactly what I wanted. Though after picking a point, I got another message asking me to select a new location for a point. So I created an ActionMacro recorded me placing the first point and cancelled the rest of the actions. 

I greatly appreciate your help. Thanks and have a good day.

[AleCVx]

Thanks heaps everyone!

[Udo_Huebner]

---

@AleCVx  schrieb:

Thankyou everyone for the speedy replies.

@Udo_Huebner , I tried out your script and it works!! that's exactly what I wanted. Though after picking a point, I got another message asking me to select a new location for a point....

That was the idea of the lisp macro, but I suppose you didn't quite understand it.
It's a loop, you can select as many points as you need.
Instead of "Pick a point" you could just improve the message to.
"Pick a point or <press Enter key to exit>:"

Then what's the point of the action macro?

[Udo_Huebner · Accepted solution]

And if you want to improve it with descriptions, then

Prompt for Descriptins as well 

and use the modified macro attached to this screencast: https://autode.sk/3il1dkv 

[AleCVx]

Thankyou very much for the additional help. I greatly appreciate your time and reply. Have a good day.