Surface TIN Error

[tremblay]

We have created a surface made from corridors & breaklines.   During the initial surface creation process the surface appeared to be fine, but as we went thru and started doing edits and adjustments of the corridor the surface is starting to added erroneous points that are created spikes in the surface.   The attached image shows what the surface is doing. 

Anyone have a solution to fix this and why this is happening?

Thanks -

[rachelc11]

I've had problems like that before. I think one potential cause could be crossing breaklines. Occasionally, even after the problem line is removed sometimes C3D "remembers" the bad point. Ways I have fixed this is by either turning points on in the surface style and removing the bad point or if that fails, by removing all the breaklines and then adding them back in at the same time. 

From trial and error, I've found it's best to make as many finalized breaklines as possible before adding them into the surface. After they are in the surface and you start tweaking, things may go just fine or if you make one wrong move, you will get weird stuff happening and fatal errors.

[dasindog]

I've had this issue too. I agree with rlcarlson11 on waiting to add all your breaklines at once. One thing I like to do is have a working surface that I am adding all the components to as needed. When the featurelines have been modified accordingly and I consider it "complete" I will create a new surface, adding all the corridor surfaces and featurelines to the surface with as few steps as possible. I also never do any tin line or point modifications on the surface until I am done and ready to start working on the way the surface contours display. I tend to get more errors in surfaces when I paste grading group surfaces into other surfaces. 

Hope this helps. Good Luck.

[atwitsend74]

In your surface display style,  turn on your point visibility.  If the point has a circle around it, it was an additional point created by AutoCAD.  It problaby means you're using the "minimize flat areas" option, and AutoCAD doesn't update these very well when things change.

If this is the case: you can go to 'edits' under the surface definition, find the "minimize flat areas" edit and remove it.   Just be careful next time you add 'contour data' to un-select any options that let AutoCAD create points for you.