How to Model Terrain from Scratch in SketchUp
Without contour lines that define the shape of the terrain you want to model, you have to start with a level surface. Use the From Scratch tool to create a big, flat rectangle that represents a chunk of ground.
Because the rectangle is already divided into triangular faces, it’s easy to use the Smoove tool to shape the rectangle into hills, valleys, sand traps, and whatever else you have in mind.
Here’s the thing, though: It’s a very rare occasion that you have carte blanche with a piece of land. Unless you design something like a golf course in the middle of a dry lake bed or terraform a new planet for colonization, you probably have preexisting terrain conditions to contend with.
And if that’s the case, you’re probably better starting off with a set of contour lines that describe those conditions.
So although the From Scratch Tool works great, you’ll probably not need to use it much. All the same, here’s how to do so, just in case.
Follow these steps to create a new terrain surface with the From Scratch tool:
Choose Draw→Sandbox→From Scratch from the menu bar to activate the From Scratch tool.
Type a grid spacing amount and press Enter.
The default grid spacing amount is 10 feet, which means the tool draws a rectangle made up of squares that are 10 feet across. The grid spacing you choose depends on how big an area you’re planning to model and how detailed you plan to make the terrain for that model.
If you’re modeling a single-family house on a reasonably sized lot, use a grid spacing of 2 feet — which would provide enough detail for elements like walkways and small berms without creating too much geometry for my computer to handle. If you were laying out an 18-hole golf course, on the other hand, you would choose a grid spacing closer to 50 feet and then add detail to certain areas later.
Click to position one corner of your new terrain surface where you want it.
Click to determine the width of the surface you’re drawing.
Click to establish the length of your new terrain surface.
When you’re done, the great big rectangle you’ve created will automatically be a group. Double-click with the Select tool to edit it and get started. You’ll probably decide to use the Smoove tool next.