What does a Surface become outdated, and hence need rebuild?

[soonhui]

The documentation says that

 If the surface definition is out-of-date, is displayed next to its node in the Prospector tree.

But what does out of date mean, exactly?

After I rebuild a surface, and then I start to add or delete vertex ( or line), will that render the surface out of date? Under what circumstances will the software deem the surface is out dated?

Secondly, if I now rebuild the surface again, what will happen? Will the software replace all the lines with the internal generated one, hence overriding the lines that I manually add?

[AllenJessup · Accepted solution]

Any change to the Surface, Edit or change to the data used to build the Surface, will make the Surface Out-of-Date. A rebuild will not eliminate your edits. It will take them into account when rebuilding. Everything that is checked in the lower pane will be used for each rebuild.

One way to avoid this is to set the Surface to Rebuild Automatically. The downside is that a rebuild can take some time with large or complicated Surfaces

[neilyj666]

....and to add to @AllenJessup reply, the surface is rebuilt in the order top to bottom so the outer boundary (if you have one) would usually be the last entry