Tools on Surface Extension

I love extensions. And Tools On Surface might be my favorite (along with Soap Skin & Bubble which I’ve mentioned before and will mention again).

This is one of SketchUcation’s extensions. See our post on how to get SketchUcation’s ExtensionStore.

Why Tools on Surface?

We all know SketchUp’s native drawing tools: Line, Rectangle, Circle, 2 Point Arc, etc. These tools are intended to draw on flat faces only. But they’re not designed to draw on irregular surfaces, such as curved faces or terrain.

Tools On Surface (TOS) provides a similar set of drawings tools, and they draw on anything.

Here’s a simple example: slicing steps in half. Using the TOS Line tool, start the line at the top of the steps and end the line at the bottom. The resulting line follows the step surfaces.


By adding a few extra lines, I can easily separate the steps into two, uneven parts.

Tools on Surface for Terrain

As a landscape architect I use TOS all the time, to draw directly on terrain. In this model, I want to draw outlines around the forested tree locations. Using the TOS Line tool, I just click the line’s start and end points. The line (shown below in white) automatically adheres to the surface, following the curvature of the terrain.

You can draw closed loops of lines or arcs to subdivide an organic surface. In other words, you can effectively draft right on terrain, carving up an aerial.

Here’s another example, in which I needed to generate new grades on existing topography. The house and walls are dropped onto the existing terrain model. And it’s clear that the structures are being covered by terrain, or not sitting well within the grades.

With TOS it’s very simple to draw an outline around the structures. This outline will be the grading extent line (or in real world terms, where the soil around the home will be adjusted and re-graded to fit the existing ground).

The terrain inside the outline is then deleted, leaving a hole in the terrain.



Now I can easily go back and use other tools to add new terrain and contours that better match the site and building.

(Want to see more? As part of the videos on my website, I review this method in detail.)

And keep in mind, I only demonstrated the TOS Line tool. There are other tools, including offsetting irregular surfaces. It’s worth trying this out on a a simple cylinder or sphere.



About Daniel Tal

Daniel Tal, ASLA, is a professional speaker and a registered landscape architect with over 17 years of experience. He is a 3D modeling and visualization expert, has authored two books with Wiley and Sons: SketchUp for Site Design and Rendering in SketchUp and is the tech-editor at large for Landscape Architecture Magazine. Tal runs a 3D modeling and visualization studio for Stanley Consultants, a 1,000 person multi-disciplinary engineering firm. Read more about Daniel.