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Author Topic: export a cad version of a 3d building survey  (Read 3424 times)

barrubba

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export a cad version of a 3d building survey
« on: October 30, 2020, 03:08:17 AM »
Hi all!
My client want to compare a 3d dwg of a project with the current building state.
So he asked me to do a building drone survey to generate a 3d that he will import in cad to compare as said.
I've told him that is impossible to import on the fly the model. becouse of million of polygons
Where is the solution? How i can edit the 3d to export a cad version? obviously mantaining as much as possible the exterior shape
I have to remodel from scratch in 3dsmax??
Thank you

chrisd

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Re: export a cad version of a 3d building survey
« Reply #1 on: October 30, 2020, 04:24:29 AM »
You may not need a CAD model to do a comparison.

CloudCompare can do deviation comparison from point clouds or meshes.
The CAD model would need to be converted to a mesh because CloudCompare does not accept CAD formats.
A quick way to get a mesh would be to export from AutoCAD to an STL.

barrubba

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Re: export a cad version of a 3d building survey
« Reply #2 on: October 30, 2020, 03:12:23 PM »
The problem is client will use autocad to do all measures and comparisons.
Can be a good idea to export from MS in 3dsmax and create a new building overlapped to 3d survey model?
It seems that an intermediate step is necessary to go from cloud to cad
I need a super accurate accurate model that respect real survey spatial dimensions.
Which can be best workflow?
something similar to this ? https://knowledge.faro.com/Software/As-Built/As-Built_for_AutoCAD_Software
« Last Edit: October 30, 2020, 03:21:37 PM by barrubba »

Dieter

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Re: export a cad version of a 3d building survey
« Reply #3 on: October 30, 2020, 08:01:39 PM »
There is no solution to this problem. All CAD programs I know cannot do anything with the 3D data from Metashape.

The only possibility offers e.g. the point cloud data in Autocad. With Autocad on-board tools, the point cloud can be compared with a 3D model without major problems.

Dieter

Outis79

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Re: export a cad version of a 3d building survey
« Reply #4 on: November 06, 2020, 04:28:23 PM »
There is no solution to this problem. All CAD programs I know cannot do anything with the 3D data from Metashape.

The only possibility offers e.g. the point cloud data in Autocad. With Autocad on-board tools, the point cloud can be compared with a 3D model without major problems.

Dieter

Importing a high resolution mesh in Autocad is a challenge also for the most powerful workstations. As Dieter said export the pointcloud (e57) from from Metashape, use Recap to create a .rcp  poject and import it in Autocad.