Adding a mesh surface to imported autocad 3d points

[sjefkins]

Hello, I have been asked whether it is possible in Inventor to add a mesh surface to imported autocad 3d points.

My customer has had a geographical site survey done, and has an Autocad drawing with a few hundred spot heights. The spot heights do have a a relative 'z' dimension.

He wants this to be the basis 3d assembly model for his entire plant.

I have imported them into Inventor (had to go back to release 2014 , as 2017 kept 'hanging' on the import) but they just come in as a 3d drawing as lots of crosses in space.

Many thanks

Steve J

[VinodBalasubramanian]

You could create a mesh in AutoCAD. Is there a specific reason why you want to do it in Inventor,

https://knowledge.autodesk.com/support/autocad/getting-started/caas/CloudHelp/cloudhelp/2016/ENU/Aut...

[sjefkins]

Hi many thanks for your message and suggestion.

I have tried a few types of mesh creation in autocad, the most suitable as far as I could tell is PFACE but this means individually picking points and making them vertices.

However in this case this is not really a viable option as there are over 2700 points. - they are just random points in 3d (each actually made up of two lines crossing at right angles).

Thanks for the suggestion anyway.

Cheers

Steve

[VinodBalasubramanian]

Hi,

Thanks for the reply. Can you share the drawing with us. Is the data that you have is a point cloud data. Do let me know the details. I will be able to see if we can do something from both AutoCAD or Inventor side to help you with that.

[sjefkins]

Good morning Vinod 
Thanks for your message.
This is the file - I have tried with just a few small areas just to see what would work.
Currently this is just as 2010 version file as that is that only software version I have here on site today, though at my office at home I am currently on 2017 Inventor / Acad suit. 
Many thanks
Kind Regards 
Steve Jefkins
Steve Jefkins Engineering & Draughting Services2 Barnsoul Mill CottageShawheadIrongrayDumfresScotland

[VinodBalasubramanian]

Hi,

For some reason i couldn't find the drawing in your attachment. Can you please reattach it.

[sjefkins]

Hi Vinod

Sorry there seem to be issues with attachments - am trying again.

Cheers

Steve Jefkins

[WHolzwarth]

That's what I got, using Rhino's patch feature with a 40 u - 40 v surface.

I broke a 50 u - 50 v surface because of too long time.

Walter

[sjefkins]

Hi Walter

Thanks for trying - Looks possible but seems to be a z axis scale issue going wrong somewhere.

I will investigate further - assume the Rhino patch is a download add-on to AutoCad?

Many thanks

Steve

[WHolzwarth · Accepted solution]

No, Steve. Rhino (or Rhinoceros) is a separate software, especially for modeling tasks.

AutoCAD Civil 3D seems to be able for tasks like that, but I have no access to it.

And you're right, the Rhino surface is only a non-precise approximation.

[sjefkins]

Hello again, yes as it is an additional software package I would need, then there seem to be others more suitable on the market. 

One I have looked at is Kuble Cubed Earthworks, which imports survey points and imports / exports dxf files. - That then may be the option to go for.

Thanks for you help.

Cheers

Steve

[roethbrad]

Hi

seen your post from years ago. I have Inventor 2020 pro and civil 3d and want to take survey data and have a accurate mesh, surface or solid for Inventor when I am done. Is there a process out there to make it possible in the end to work with Inventor files from survey point data? 

Please reply to brian@watersmithengineering.com 

[johnsonshiue]

Hi! Unfortunately, I don't believe there is a straight forward workflow in Inventor to do what you want to do. The reason is that Inventor's precision is much higher than the survey data. The survey data is massive but loose. What are you trying to achieve with the points in Inventor?

Many thanks!

[sjefkins]

It was a few years ago, but my client had a 3d autocad drawing of his site, with hundreds of imported survey points. We were trying to generate a model of the ground around the various plant and buildings on his site. - Was rather a large assembly, but we couldn't figure out a way to generate either a mesh or a solid which linked all the points.

[sjefkins]

Hi Brian

That was a while ago, but from memory no I didn't find a way to create the mesh.

If you do find a way please let me know.

My client at the time were looking into a civils package - Kubla Cubed

Sorry I can't be of more help.

Kind Regards

Steve Jefkins

[arron.craig]

I know this is an ancient post but I'm waiting for some FEA so will give this a shot. 

You can get a mesh out of this survey data but as Johnson mentioned, the scale is too big for Inventors 100m bounding box limit. 

Regardless here's how I did it with either only Autodesk software or with the help of some open source software at the end. 

Firstly, all those coordinates in the file that Steve uploaded appear to just be line segments and text when viewed in AutoCAD 2023. Maybe it's different in Civil3D, I don't know but I just want points for now. 

1. In AutoCAD, Create a block with nothing but a "point" in it at 0,0,0. The block should also be called "point".

Run the attached lisp file with Insert@MidLine (courtesy of @CADaSchtroumpf) to place the block containing a point at the midpoint of every line. (there will be double ups because there are two intersecting lines but that is fine)

2. Remove the lines and text if you like and you should be left with a cloud of points (or blocks I guess). Now use dataextraction to extract only the "position" of the blocks titled "points"

 

 3. With the dataextraction tool, export this data to a .csv file. Open the .csv and delete everything except the x,y,z data. Now copy and past all this data into notepad and save it with the .pts file extension.

4. You now have a point cloud file that can be imported into Autodesk Recap or CloudCompare (free)

Recap will be able to mesh this file if you have cloud credits to spend. Otherwise you can import to CloudCompare and create a mesh in a couple of clicks. 

 

 

 

 

[sjefkins]

Many thanks Aaron

Sorry been away for a few days. I'll give your suggestion a try later today, hopefully I still have the original old 3d site model somewhere.

Cheers

Steve

[cadman777]

I tried aaron's lisp file but it didn't work.

The 2nd one on this link worked for me.

This is the work-flow I used:

1. In AutoCAD, RMB>QuickSelect.

2. Select all vertical lines and place on another layer and TurnOff that layer.

3. Make layer '0' active and run the LISP command.

4. TurnOff the layer that the lines are on.

5. Select all points and either export them or TurnOff that layer and TurnOn all other layers and delete everything on them so you have only the points in the current drawing.

6. Do a PurgeAll on the drawing.

7.  Import that dwg file into Rhino or other software and process accordingly.

8. Here's a simple Rhino method. Otherwise, you can import the dwg file into Rhino and use a Grasshopper script to create a very nice 3d survey. YT has some instructions. I've done it in 1/2 an hour following the YT tutorials. There are a number of ways to do it too, some simple, some more complex. Just go to YT and type in "grasshopper: point cloud" and see which ones you like.

9. I tried CloudCompare but I had to scale it down by 1/10 (it gave a 'too large' error). In contrast, the pointcloud opened up perfectly in Rhino using the AutoCAD file.

(this post was updated)