View the scene

How to tumble (orbit), track, dolly (zoom), and customize the scene view.

Tumble, track, and dolly

Space +		Tumble
Space + , or		Dolly
Space +		Track
Space + Ctrl +		Tilt the camera
Space + Alt +		Zoom the camera lens
Space + Ctrl +		Box zoom Drag the box from left to right to zoom in on the area inside the rectangle. Drag the box from right to left to zoom out (so the current view fits inside the rectangle).
Space + Z	Center view tumbling on the point under the cursor.

Hotkeys

Space + H	Home: center the view to show all objects/geometry.
Space + G	Center the view on all selected objects/geometry.

Changing the viewport layout

Click the viewport layout menu icon on the viewer toolbar and choose a layout from the menu.

To quickly switch from a multi-viewport layout such as the four-up and widescreen three-port layouts to a single viewport, move the mouse over the viewport and press Space + B. Press Space + B over the single viewport to switch back to the multi-viewport layout.

To have the orthographic viewports pan and zoom together, open the viewport layout menu and choose Link ortho views.

Homing the view

Homing means to reset the view, either to a default view looking at the origin. You can also home to show all objects in the scene, or to show the selected objects. This is similar to the “zoom to fit” functionality in 2D illustration programs, PDF and image viewers, and so on.

Homing and framing controls are located in the viewport options menu (the left menu in the top right corner of viewports). This menu contains commands for homing the view, and lets you customize the default home view. For most homing functions, you’ll want to use the hotkeys.

To…	Viewport menu command	Hotkey
Zoom to fit all objects.	Home > Home All	Space + A
Zoom to fit the selected objects.	Home > Home Selected	Space + G
Zoom to fit the grid.	Home > Home Grid	Space + H

Customize home view

To...	Do this
Change the home view to a look along an axis	Open the viewport menu, click Home, then choose a view direction (along the X-axis, Y-axis, or Z-axis).
Change the home view to look along a custom direction	Use the tumble keys (see above) to get the view you want as a custom home. Open the viewport menu, click Home, then choose Customize Home. Open the viewport menu and click Home again, then from the list of home options choose Custom. Now when you use the homing hotkeys, you should return to this view.

To change the “home” view direction, open the viewport options menu

Changing the display of geometry

To...	Do this
Show or hide different geometry features	Click the icons in the display options toolbar (on the right side of the viewer pane) to show or hide different types of information of the 3D scene view. For example, you can show/hide points, point numbers, and point UV and XYZ coordinates. If normals are hard to see at the scale you're working, you can adjust their length in the Misc tab of the display options window (see below).
Open the full display options window	For greater control of the display, open the viewport options menu and choose Display > Display Options or press move the mouse over the viewer and press D.
Switch between wireframe and shaded mode	Open the viewport options menu and choose Shading > Toggle wireframe/shaded, or press W.
Change the shading in the viewer	Click the shading mode menu icon and choose a shading mode.
Use different feature visibility/shading for selected and non-selected geometry	You can set different display modes for normal (non-selected) and selected geometry. So, for example, you can only show hulls on selected surfaces. Open the display options window (see above). Click the Guides and Markers tab. Set the pop-up menu at the top to Selected Geometry. Turn off the Same as normal geometry checkbox. Set the display options for selected geometry.
Control the feature visibility and shading of templated and “current” surfaces	Templated surfaces are the result of a surface node with the template flag set, which means the surface is visible for reference, but doesn’t render. “Current” surfaces result when you are inside a Geometry container object and you select a node other than the display node. Houdini shows the geometry from the display node using the normal display settings, and the selected node using these settings (usually wireframe). This lets you edit the geometry of the selected (“current”) node and see the effect on the display node at the same time. Open the display options window (see above). Click the Guides and Markers tab. Use the pop-up menu at the top to choose Templated Geometry or Current Geometry. Set the display options for the chosen type of geometry.
Visualize the display of attributes	See attribute visualization.
Turn off primitive highlighting so that you can see the UV texture beneath	Change the Shading Mode to Smooth Wire Shaded.

See also how to optimize drawing and tumbling of large scenes.

Show or hide other objects

When you're editing geometry, particles, or dynamics inside an object, you can choose how/whether Houdini displays other objects and levels in the scene using the Show all/current/ghosted menu.

	Show ghosted	Other objects/levels appear “ghosted” (semi-transparent). This is the default.
	Show others	Show other objects and levels normally.
	Hide others	Only show the geometry at the level you're working and hide others.

Shading modes

	Wireframe bounding box	Only draws a wireframe bounding box to represent geometry.
	Shaded bounding box	Only draws a shaded bounding box to represent geometry.
	Wireframe	Draws curves, surface isoparms, and polygon edges.
	Hidden line invisible	Like Wireframe, but does not draw lines are obscured by surfaces.
	Hidden line ghost	Like Hidden Line Invisible, but lines that are obscured by surfaces are drawn faintly.
	Flat shaded	Shades polygons but does not blend between them, making them appear faceted.
	Flat wire shaded	Like flat shaded, but also draws the wireframe over the shaded surfaces.
	Smooth shaded	Blends between shaded polygons making them appear smoother.
	Smooth wire shaded	Like smooth shaded, but also draws the wireframe over the shaded surfaces.

Note	Shaded modes can only show a maximum of eight lights. This is a hard-coded limitation of OpenGL.

How to look through a camera or light

To...	Do this
Match the view to a camera or light	Click the camera menu in the viewport (to the right of the viewport options menu) and choose a camera or light to look through. Normally using the tumble keys after looking through a camera or light will switch the view back to “no cam” – by default the view has no connection to a camera/light. See the Lock camera/light to view button below for how to tie the view to a camera or light.
Match a camera or light to the current view	Click the camera menu in the viewport (to the right of the viewport options menu) and choose Save view. Choose a camera or light from the pop-up menus and click Accept. Moves and rotates the chosen camera or light to look down the current view.

To...

Do this

Match the view to a camera or light

Click the camera menu in the viewport (to the right of the viewport options menu) and choose a camera or light to look through.

Normally using the tumble keys after looking through a camera or light will switch the view back to “no cam” – by default the view has no connection to a camera/light. See the Lock camera/light to view button below for how to tie the view to a camera or light.

Match a camera or light to the current view

Click the camera menu in the viewport (to the right of the viewport options menu) and choose Save view.
Choose a camera or light from the pop-up menus and click Accept.

Moves and rotates the chosen camera or light to look down the current view.

Use the view keys to position a camera or light

Normally the Houdini viewer is set to “no cam”, meaning it’s not looking through any camera or light. When you choose a camera or light from the camera menu, the viewer switches to look through that camera/light, but if you use the tumble/track/dolly controls to change the view, the viewer switches back to “no cam”: using the view keys to change the view does normally move a camera or light.

To use the view keys to move the camera or light you are looking through, you need to lock the view to the camera/light.

Choose a camera or light from the camera menu in the viewport.
In the display toolbar (on the right side of the viewer), click the Lock camera/light to view icon.
or
Open the camera menu in the viewport and choose Tie camera (or light) to view.
Use the view keys (see above) to move the camera or light.

How to create a new camera from the current view

Click the camera menu and choose New camera, or Ctrl-click a camera or light icon on the shelf.

See the sections on cameras and lights for more information.

How to put an image in the background of the 3D viewer

Click the viewport options menu and choose Display > Display options, or press D.
Click the Background tab.
On the Image Source sub-tab, select the image file to use as the background. You can alternately select the output of a compositing node.