Houdini 20.0 Geometry

“Box up” modeling

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“Box up” modeling refers to starting with a basic shape such as a polygonal box or sphere and then adding, extruding, modifying, cutting, deleting, smoothing, etc. polygons to build up the shape you want.

Another way of modeling is “curve up” modeling, where you create construction curves that define shapes, then use tools such as Revolve and Loft to create surfaces from the curves.

See the Model tab on the shelf for more modeling tools.


See how to create geometry.

Moving points

Extrude faces/edges

PolyExtrude tool on the Polygon shelf tab. This shelf tool creates a Poly Extrude surface node.

Split faces

PolySplit tool on the Polygon shelf tab. This shelf tool creates a Poly Split surface node.

Remove faces

Select the faces and press ⌦ Del.

Delete tool on the Modify shelf tab. This shelf tool creates a Blast surface node.

Smooth polygons without adding points

Smooth tool on the Polygon shelf tab.

To smooth points by painting, use the Sculpt tool on the Model shelf tab. In the viewer, press RMB and set one of the mouse buttons to Smooth points. Use the Opacity control to set the amount of smoothing.

Increase the number of polygons with optional smoothing

Use the Subdivide tool on the Polygon shelf tab. This shelf tool creates a Subdivide node which divides polygons into smoother, higher-resolution polygons.


Use the following tips to set up for box-up polygonal modeling:

  • You can place an image in the background of the 3D viewer as a reference for modeling.

  • You can turn on Link Ortho Views in the viewport layout menu (in the toolbar across the top of the viewer pane) to make the top/front/side viewports pan and zoom together (see the section on the view).

  • Press P in the viewer to overlay a parameter editor for the current operator/tool.






  • Destruction

    How to break different types of materials.


Next steps

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