Section Planes: Slice is Nice

Visualizer's interactive support of section planes has been an especially popular feature. The new Visualizer 1.2 release (yes: it's now out of beta!) added a little bit more functionality: correct support (in SketchUp 2015) for the global section cuts on/off flag (old versions of SketchUp didn't have the right "hooks" for this feature, while 2015 works perfectly!).

Let's explore section plane usage a little, to better understand how section cutting works in Visualizer, using our handy reference model, the WikiHouse Studio:

WikiHouse Studio, SketchUp Plan Section
WikiHouse Studio, Visualizer Plan Section

Both Visualizer and the main SketchUp view draw the model in the same way, but Visualizer preserves the light and shadowing, so that the natural look of the model is preserved. This is often what you need, especially when working with interiors like this one that are very dependent on natural light to look right.

Here are a few more views of this model, comparing SketchUp and Visualizer renditions with and without section cuts:

WikiHouse Studio, Inactive Section Plane Parallel to the Windows
WikiHouse Studio, Inactive Section Plane Parallel to the Windows
WikiHouse Studio, Section Plane Oblique View in SketchUp
WikiHouse Studio, Section Plane Oblique View in Visualizer
WikiHouse Studio, Window On-Axis View in SketchUp
WikiHouse Studio, Window On-Axis View in Visualizer
WikiHouse Studio, Section Plane On-Axis View in SketchUp
WikiHouse Studio, Section Plane On-Axis View in Visualizer

In some cases, Visualizer's shadowing choice might lead to dark areas in the picture. A simple solution is to hide shadowing parts of the model that are clipped-away by the section plane anyway.

In the image that started this blog entry, we sliced down through the top of the house for a second-story plan section. In the image below, everything is the same, except that we've turned off visibility for the roof object itself, which was in its own layer:

Glass House Section with Unseen Roof Layer Hidden

This method gives both more light spilling into the space while still letting the section plane do its work of removing the ceiling and support trim so that the image is clear and understandable.

(Yes, we could also have just tweaked the per-entity shadow settings for the roof, instead of hiding the layer, and never had to give it a second thought! You can choose the style that suits you and your projects.)

The same method can be used when using standard textures, rather then the color-by-layer views we've shown:

Glass House Section with All Colors and Textures

In this circumstance some of the darkest areas go truly dark, simply because they have near-black textures (e.g., inside the brick column).


As we mentioned before, while section planes work in SketchUp 2013, 2014, and 2015, the global section plane on/off control (the View->Section Cuts menu item) can only be supported in SketchUp 2015 or higher, due to some issues regarding how SketchUp works internally. Likewise, at least for today, only one section plane can be active at a time, and grouped section planes may not do what you expected or may not appear at all.

For each of these three cases, there are workarounds, and of course we're working as hard as usual to find ways for Visualizer to just work for you without a second thought about tweaks and settings and special cases. If you use section planes, or have some great ideas (or needs) regarding sections, please don't be shy about contacting us and letting us know what they are -- it's always a win-win situation.

(Bonus Link! Check out Architizer on great sectional drawings of the past)