Creating a TIN surface from an autocad mesh

[Anonymous]

Hi everyone

I've been struggling with creating a correct TIN surface. First i've created a region using the sweep comand on a trapezoid shape and a 3d polyline as the route. Then, i've generated a mesh of triangles (maximum angle 90°, maximum lenght 0.50m) then exploded this mesh to obtain a group of 3d faces wich i want to use to create a TIN surface. The problem is that when i define the TIN surface with this drawing objects (3d faces) it generates an irregular surface that doesn't coincide with the shape of the 3d faces. Also i know that i can produce this surface using assemblies but i find it a little difficult.

Thanks for any insights!

p.d. I know that i can't generate a TIN surface when some of the faces are vertical relative to z, so none of the faces are this way

[andrewpuller3811]

When you are adding the 3d faces to the surface are you checking the option to maintain the edges of the triangles? 

I know you are doing a sweep to get your faces, but you might get better results by offsetting you 3d polyline and adding those as breaklines to a surface.

[Anonymous]

Hi, thanks for answering!

I've tried add the drawing objects both ways (checking and not checking the option "mantaining edges from objects") and the results are different but yet imprecise. Also tried defining the TIN surface with offseted lines as you sugested and the results are again different but not what i'm looking for. However i believe that the problem is due to the side faces of the canal are too much steep and this could be causing the triangulation error, so i incremented the slope of the faces (from nearly but not vertical, to a more visible slope) and the triangulation got much better.