Slice topographic contour lines

- [Narrator] The lines that we see on the NURBS surface…are called isoparametric lines, and they are constant…in these internal mathematical representations…of U and V parameters.…And that's fine as far as it goes,…but it's not something that we're interested in…in terms of architecture.…In architecture, we tend to like to see contour lines,…let's say at every foot in elevation.…And this will give us a sense, in the model,…of the steepness of the slope,…and we can create those from the surface,…and I'd like to show you how.…

It starts by generating objects…at every one of these elevations that we want to have…contour lines on.…So I'll start by drawing a rectangle…from this corner over here…to this opposite corner.…If you recall, that was the shape…of the original surface that we later trimmed.…I'm going to copy this rectangle and this surface…over to the side, some set distance.…It looks like about a hundred feet would work well here,…so I'll type that in.…

So we have a copy over here.…Now, we have a rectangle at the top,…