Basics Quick reference

The selection mode controls

• What you can select in the view.

• What node appears in the parameter editor

• What handles appear when you click the Handles tool.

When you select in object mode, the parameter editor will show the parameters for the object (e.g. a light, a geometry container, camera, bone, etc.). When you select in component mode, the parameter editor will show the parameters for the surface node with the display flag.

1	Select objects When you click geometry in this mode, the object is selected. Right click this icon for a menu of object types where you can choose which types of objects are selectable.
	Select components Right click this icon for a menu of component types. 2 Points 3 Edges 4 Faces 5 Vertices Breakpoints Point groups Face groups When you click geometry in this mode, any components of the chosen type (faces, edges, points, breakpoints, point groups, or face groups) will be selected.
F8	Switch between object and component selection
	Select particles Right click this icon for a menu where you can choose selecting particle nodes vs. individual particles. See particle systems.
	Select dynamics Right click this icon for a menu where you can choose whether to select dynamics objects and/or dynamics modifiers (e.g. forces). See dynamics.

More information

The toolbox is located along the left side of the 3D view.

	S	Select Use this tool to select objects or geometry before applying one of the shelf tools.
	T	Move
	R	Rotate
	E	Scale
	Enter	Handles Use this tool to access handles and operator controls specific to the selected object. Right click this icon for a list of available handles.
	Esc	View This is a convenience tool: it provides the viewing controls ( tumbles, tracks, dollies) without having to hold down the space bar.
		Render region This tool lets you drag out a rectangle in the 3D view to test render part of the scene.

Hover over items on the shelf to see a short description of what they do and how to use them. Press F1 while hovering over a tool to open detailed help on the item.

Many tools require some interaction in the viewer. For modifier tools, select the geometry you want to work on and then click the shelf item. For creation tools, click the shelf item, then click in the viewer to place the new geometry.

More information on the shelf

While you are using a tool, options for the tool are available in the operation control bar across the top of the viewer.

Most shelf items will create a new node or nodes somewhere in the network.

In Houdini, each piece of geometry is represented by a container object called a Geo object, which contains a network of surface nodes.

The surface nodes define the geometry, and the object provides overall transforms for the geometry.

• Connect object nodes to create parent/child relationships. The “output” object is the parent of the “input” object.

• The blue “visible” flag controls which objects are visible in the scene and renders.

• The green “selectable” flag controls which objects can be selected in the view. This lets you protect certain objects (such as bones or lights) from being selected accidentally.

• Connect surface nodes flow geometry from generator nodes that create geometry (such as the Sphere node) through filter nodes that modify or combine geometry from input nodes.

• The display/render flag marks which node represents the geometry of the object. The node with the display flag is marked with a large ring in the network editor.

• You can choose separate nodes to (a) represent the object in the viewer and (b) render. To set a node as the render node, Ctrl-click its display/render flag. The node with the render flag is marked with a large colored circle in the network editor, while the node with the display flag has a large ring.