Practice Notes: SketchUp

From Sean Akahane-Bryen
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Useful Extensions

An inexhaustive list:

Useful Keybinds (Windows)

Keys can be bound to any function in the Shortcuts tab of Preferences:

Viewing and Navigating

Key Function
H Edit/Hide*
Ctrl + H View/Component Edit/Hide Rest Of Model
Ctrl + Alt + H View/Component Edit/Hide Similar Components
Alt + H View/Hidden Geometry
Alt + M View/Face Style/Monochrome**
Ctrl + Alt + S Tools/Section Plane
Ctrl + Shift + Alt + S View/Face Style/Shaded With Textures
Alt + T View/Face Style/Shaded With Textures
U Edit/Unhide/Selected
X View/Rendering/Edge/By Axis***

* Normally mapped to `Camera/Pan` ('H' for 'hand'), which can be mapped to `W`
** Useful for checking for flipped faces, which may be invisible once a model is textured.
*** Useful for checking imported geometry for orthogonality.

First Person Camera

Note of caution: Left Alt + Shift is a standard Windows shortcut for cycling through keyboard input languages.

Key Function
Alt + Shift + F Camera/Look Around ('F' for 'Free look')
Alt + Shift + S Camera/Position Camera
Alt + Shift + W Camera/Walk
Alt + Shift + V Camera/Field of View

Groups and Components

Key Function
G Edit/Make Group
Ctrl + G Edit/Make Component...

Selecting and Editing

Key Function
Shift + E Edit/Item/Select Only/Edges*
Shift + O Edit/Item/Orient Faces**
Shift + R Edit/Item/Reverse Faces**
Alt + Shift + X Tools/Axes
Ctrl + Alt + X Edit/Item/Explode

* Function will not appear in the list in Preferences unless some arbitrary geometry containing at least one edge is selected. Useful for playing down surface articulation. ** Function will not appear in the list in Preferences unless some arbitrary geometry containing at least one face is selected.


Key Function
Ctrl + Shift + A Window/Show Entity Info ('A' for Attributes)
Ctrl + Shift + C Window/Show Scenes
Ctrl + Shift + E Window/Show Soften Edges
Ctrl + Shift + P Window/Show Components
Ctrl + Shift + S Window/Show Shadows
Ctrl + Shift + T Window/Show Styles
Ctrl + Shift + Q Window/Show Layers*
Ctrl + Shift + Z Window/Show Materials*

* Mapped to odd keys so that these are in reach of the left hand.

Drawing and Manipulating Geometry

Circles and circular arcs

SketchUp is a polygon-based modelling software and does not natively support NURBS objects. Circles are approximated by many-sided regular polygons.

  • After drawing a circle or arc, the number of sides/segments in the circle/arc can be determined by typing [n]s where [n] is the desired number of sides/segments.
  • If the number of sides/segments in a circle is set to a multiple of 4, SketchUp will be able to snap to the points on the circle tangent to the x and y axes.
  • ThomThom's Guide Tools extension can be used to generate construction points at the centre of circles and regular arcs, for easier gripping.
  • For even easier gripping, group the circle or arc, draw construction lines intersecting at the centre, and group the circle and construction lines together. (This way, the construction lines don't break the circle or arc into smaller arcs.)

Starting a new model from dwgs

Note on importing .dwgs from Vectorworks: Geometry on non-active layers—even if switched on an visible—sometimes(?) gets exported/is imported in SketchUp displaced. This can be avoided by pasting the desired geometry into a new drawing before exporting.

  • Geo-locate an empty SketchUp model (or template).
  • Draw a plane to establish RL0 (or some other useful RL) and lock it.
  • Import dwgs into a separate model (for easy layer management). Clean up stray geometry (especially that which is far from the origin). If not already on, use View/Rendering/Edge/By Axis to check for orthogonality.
  • Unless granular control is necessary, delete all layers and assign geometry to the default layer. Group each drawing and assign to a new layer (such as dwg - Survey). If CAD layers are to be maintained, prefix them with the drawing layer name (such as dwg - Survey _ Boundary, where underscores indicate a layer whose groups are contained within groups on a parent layer).
  • Paste into the geo-located model.
  • Set axes to a useful orientation (probably to match the orientation in CAD).


SketchUp does not account for Daylight Savings Time.[1]

So, for example:

  • Sydney is normally on AEST (UTC +10).
  • Between 2am on the first Sunday of October and 2am (or 3am DST) on the first Sunday in April, Sydney is on AEDT (UTC +11).
  • Shadow diagrams for the summer solstice (21/22 December) and March equinox (20 March) should be calculated using UTC +11.

SkIndigo (Indigo Render for SketchUp)

General notes/precautions:

  • The base unit of the model must be set to metres. (Particularly important when rendering textures with bump/displacement maps, and caustic effects.)

Proxy Instancing

Low-poly proxies can be used to stand in for high-poly components which would otherwise slow down SketchUp. Where the original high-poly component is named component, simply name the proxy component component_dummy.[2]


Can be simulated using a diffuse transmitter (not a distinct "Material Type" in SkIndigo's Material Editor, but a diffuse material with a clipping channel applied):[3]

Take a diffuse material, add a little transparency and there will still be a diffuse component scattering light back: that's the benefit of blending a diffuse with a diffuse transmitter. In this regard the material conversion from SkIndigo sounds correct.

The diffuse_transmitter material itself does not have a transparency parameter. There is only its albedo to multiply the transmitted light with: white and the colour are unaltered, just scattered rays and black: no light passes through, as if it was fully absorbed.

Knowing that the blend material should make sense, granted that you started with a simple diffuse material wich does only scatter light back.

edit: I'll be more specific: the diffuse transmitter alone is an ideal transmitter: it does not correspond to a real material because light is never bouncing on it (always passing through). It was meant from its conception to be blended with other materials.

Troubleshooting Displacement Maps

Check that:

  1. The base unit of the model is set to metres, and that the displacement value is set to something realistic (also in metres).
  2. The mesh/group's Max Subdivisions is set to at least 9.


Letterboxed Viewport

Some rendering plug-ins can alter SketchUp's aspect ratio and cause the viewport to appear letterboxed.

The viewport/camera's aspect ratio can be reset by typing the following in the Ruby console:[4]


  1. SketchUp Help Center: Casting Real-World Shadows
  2. Indigo Renderer Manual: Indigo for SketchUp: Instancing
  3. User CTZn on the Indigo forum
  4. SketchUp Community: How to remove the 2 grey large lines on my screen?