thanks so much for the help!

here it is

ramp.skp

Okay this might be a dumb question but how can AB be parallel to E and CD be parallel to E but AB is not parallel to CD

Thanks.

If its not planer, wouldn't the face only close where it is? Meaning if I drew a diagonal only part of the face would close letting me know where the problem is. But the whole face closes....as if there is no problem

Hello SU

I have some ramps I have drawn and to close the face of the surface of the ramp, I am having to draw a diagonal line from corner to corner. When I do that the face completely closes at all 4 corners. When I then erase the diagonal the whole face disappears....any ideas on what is happening here?

Okay actually the lines are many many segments......they are one polyline in CAD so not sure why they came in that way.

I discovered if I use simplfy contours but instead of the default 10, i use 1, its almost perfect but not still problems in some sreas with the tin not touching the contours. the computer freezes if I try to use sandbox without simplfy first

Thanks so much, will try dividing the lines this morning

Any idea on why sandbox works fine if I only select a portion of the contours?

so is simplfy contours plugin creating a problem? doesn't that reduce the vertices?

how do check the amount of vertices in each curve

Yes this part I am showing in the image is a flat sloped terrain.

I brought the contours in from CAD, simplified, and made from contours.

Can you explain a little further about the vertices?

If I select just a portion of the entire contours (for example if I were to select just half of what you see in this image) and make the tin it doesn't happen

better angle image attached