Houdini 20.0 Nodes

Geometry nodes

Geometry nodes live inside Geo objects and generate geometry.

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Geometry (SOP) networks

A Geometry object at the object level contains a geometry (SOP) network inside. This network holds the geometry nodes that create the object’s geometry.

Wiring nodes together at the geometry level controls the flow of geometry through the nodes, from nodes that generate new geometry (such as Sphere) through nodes that modify the geometry.

See geometry for more information on using geometry nodes.

SOP flags




Q or B

Bypass disables the node, making it pass its input geometry through to the output unchanged. This is useful for testing and visualizing the effect the node is having in the viewer.

When a node is bypassed, the flag on the left of the node is lit yellow.


Lock “freezes” and caches the node’s output geometry. While the node is locked, the node outputs the “frozen” geometry instead of cooking. This is usually not necessary and can be confusing, (which is why the flag isn’t clickable on the node and doesn’t have a hotkey), but it has two potential benefits:

  • If a node takes a long time to recompute, you might want to lock it to prevent it from re-cooking and work from the cached geometry. You would then unlock when you're sure you want to recook.

  • If nodes depend on external files, you can lock them to make the HIP file self-contained, since the locked nodes use their own copies of their output geometry instead of loading the data from the external file.

When a node is locked, the flag second from the left of the node is lit red, and a badge appears on the node.

Don’t confuse this “lock” with locked digital assets.


Template makes the node’s geometry visible (and snap-able) in the viewer even if the node doesn’t have the display flag on.

You can control how templated geometry is drawn in the viewport (for example, as wireframe, or shaded) in the viewport display options.

Normally, clicking the template flag on a node turns off the template flag on all other nodes. You can ⇧ Shift-click template flags to template multiple nodes at once.

When the template flag is on, the flag second from the right of the node is lit maroon, and a maroon ring appears around the node.


Display marks the node whose geometry appears in the 3D viewer. Often this is at the end of the network, showing the cumulative output of the network, but you can (and will often) move the display flag around the network to check the output of different nodes.

Normally, moving the display flag also moves the Render flag, but you can separate them, so you can set one node to provide the geometry in the viewer, and another node to provide geometry at render time. This can be useful to show proxy geometry in the viewer and render more detailed geometry.

When the display flag is on, the flag on the right of the node is lit blue, and a blue ring appears around the node.



When the render flag is on, the flag on the right of the node is lit purple, and a purple circle appears around the node.

Other SOP flags

You can set these flags by RMB clicking a node and opening the Flags sub-menu.





You can ⌃ Ctrl-click the template flag to set the Selectable Template flag. This makes the geometry visible and allows you to select components from the templated geometry in the viewport, in addition to components on the geometry with the display flag.

If you apply an operation (for example, PolyExtrude) to components from a selectable template, Houdini will automatically insert a Merge node to merge the templated geometry with the display geometry, and then apply the operation to the components in the merged geometry. This can create a mess in the network if you are not careful. In general, you may want to avoid selectable templates. Create merges yourself, and then work on the merged geometry.


The Unload flag tells Houdini not to cache the geometry output by the node. This saves memory, but slows down cooking. An exception is geometry that is being displayed, which will remain cached, since it is still in use.

When the node has the unload flag, a badge appears on the node.