Solved: Slicing a 3D Solid with a TIN Surface - Page 2

5stringb · ‎02-21-2018

I'm trying to calculate a volume of soil to be removed from a dig. I have a point cloud with ground shots from existing grade. For the sake of simplicity, let's say I have a square box with (4) walls and a basement slab, dug into the Earth.

Here are my steps:

Create a TIN surface from the point cloud to represent existing grade - no problem.
Create a 3D solid from an (around-the-walls perimeter) 2D polyline, extruded upwards by the height of the walls - no problem.
Align the (uneven) existing grade TIN surface properly near the top of the walls based on a reference elevation point - no problem.
Use the TIN surface to Slice off the top of the 3D solid, leaving the uneven top surface, square sides, and square bottom - Having trouble here.

I can't seem to use the TIN surface to clip the 3D solid. Help?

I'm also open to more efficient workflows and ideas on how to accomplish, so if I'm doing this the hard way, please advise. Thanks!

neilyj666 · ‎11-14-2018

I'm no expert on vanilla CAD Solids and Surfaces but I just MOVEd the slicing surfaces (displacement 0,0,50) which wouldn't give totally correct results but it sliced with no problem.

I think you will need to amend the slicing surface such that it is not coincident with the solid along the top

neilyj (No connection with Autodesk other than using the products in the real world)
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Anonymous · ‎07-05-2019

Hi Jowenn

I tried your method in my field of aplication withour success.

Maybe I'm doing something wrong.

I would apprecaite your kindly support.

I'm using a complex TIN surface that was constructed with photogrametric fly and ReCap Photo.

ReCap gave to me a DEM file. Then I used GLobal Mapper to get the countours and finally Civil 3D to obtain the TIN surface.

The goal is to calculate the fill volume of a mobile conveyor.

Please find attached a CAD file.

Best regards.

PMP Francisco Gonzalez

francisco.gonzalezbenitez@mm.gmexico.com

Anonymous · ‎12-01-2020

...made my day.

qchenTPPXV · ‎08-20-2023

Thank you for sharing. Just wondering when I select from object, it doesn't show the triangle. Is there a step that I missed? Thank you for your help!

qchenTPPXV · ‎08-21-2023

When in the top view, I select the Tin surface and it shows as below

It shows Triangles in 3D view.

However, when I select the desired area, and hide the surface, that area doesn't show up.

Do you know any soluctions?