DTM with 3D Poly Data Problems

[reem]

I have been struggling with creating this site model trying to figure out what's wrong with my data. I am creating a DTM using 2D to 3D Polygons. I checked and rechecked my data to assure no polygons are crossing and that everyting is set to the correct height. I tried importing it into a fresh new file. I ran the filter to simplify the vertices on the poly.

Finally I had the idea to look at the "Mod-Site-DTMData" layer in 3D view and I saw some polygons that were't flat. They were zig-zagging back and forth along the z axis. In other words, several of my 3D polygons were undulating up and down from vertix to vertix, even though the object as a whole is set to the right z-value in the objects attributes.

What happened? How do I fix it without having to re-draw these poly's? How do I prevent this from happening in the future?

[Delmer]

This can happen if you are adjusting nodes, don't have the "Constrain Working Plane" snap on (only is available when using the appropriate tools) and snap to either a node or plane on a different z coordinate.

Best thing is to convert offenders to polygons then back to 3Dpolygons.

[Delmer]

When you convert to polygons make sure you are in top plan and choose wireframe as opposed to hidden. Change back to 3d polygons setting the z in the OIP.

[Robert Anderson]

Also, make sure you are using the 3D Reshape tool and not the 2D reshape tool.

[reem]

Thanks for all of your suggestions! You guys saved me a lot of time and headache!