Select surface tool

The select operation lets you preselect geometry for the next operation.

The normal way to model in Houdini is to first choose the operation you would like to perform and then select the geometry on which to perform that operation (verb - noun). The select state allows you to preselect some geometry that will be used for the next operation to perform.

General Notes

Note

These apply to both the Select OP and the selection stage of other Operations.

Selection Types

The selection icons on the left side of the Viewport let you change the type of selection (e.g. points, primitives, edges, etc.) The 1 - 9 keys can also be used to change the selection type.

Selection Mode

The default selection mode is “replace” mode, where newly selected geometry replaces the current selection. To quickly use “toggle” mode while in “replace”, hold the shift key while selecting. While in “toggle” mode, clicking on already selected geometry will remove it from the selection, and clicking on unselected geometry will add it to the selection. The selection mode can be changed to “replace”, “toggle”, “add”, or “remove” by clicking on the menu at the left hand side of the viewer.

Box / Lasso / Paint Picking

The default selection style is “box picking”. This means that clicking and dragging the mouse will draw a box, and the current selection rule will be applied to everything in the box. The selection style can be changed to “box picking”, “lasso picking”, or “paint picking” via the menu to the left of the viewer. Lasso picking lets you draw freehand selection regions. Paint picking lets you drag the mouse over geometry to select or unselect it. While paint picking, the left-mouse-button uses “replace” mode, Shift-left-mouse-button uses “add” mode, and the middle-mouse-button uses “remove” mode.

Select Whole Geometry

The “select whole geometry” toggle at the left of the viewer lets you pick an entire geometry object by clicking on any part of it. The keyboard shortcut for this toggle is - .

Front / Back Polygon Menu

The “front/back polygon” menu at the left of the viewer lets you select front and back facing polygons, only front facing polygons, or only back facing polygons. This menu is useful when working in the UV viewer.

Non-dragable Selecting

Some operations, like transform and edit, let you select geometry and drag it while in selection mode. The moment you drag the geometry Houdini exits selection mode and begins to change the parameters of the current operation in order to drag the geometry. If you do not want to accidentally drag geometry, use the to select it instead of the .

Select Operation Menu

Select All

Selects all the object / scene geometry (depending on the status of Select From All Objects).

Toggle Selection

Unselects that which is selected, and selects that which was formerly not selected.

Select None

Deselects everything.

Select From All Objects

Normally, you work on the contents of one object within your scene at a time. Enabling this allows you to select from all the objects in your scene. Picking geometry from other objects will create object merges.

This is tied to the Select One/All icon at the bottom of the Viewport.

Usages in other examples

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