Houdini 20.0 Rendering

Working with render nodes

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Houdini provides different types of render nodes:

  • Nodes corresponding to renderers and scene description formats (such as the Mantra node and RenderMan node). These nodes output scene description files and call the appropriate renderer to render the file.

  • Nodes for generating other outputs, such as the Geometry node which “renders” the scene geometry to a geometry format such as .bgeo or .obj.

  • Utility nodes to control renders and dependencies. For example, you can use the Merge node to sequence renders. You can use the Switch node to switch between different render nodes based on an expression.

For example, you can set up different output nodes for different render qualities (such as test render and final render) and independent render passes. Or, you can render a scene with different renderers.

Each driver renders the view of the scene through a camera. For a driver to work correctly, the camera associated with the driver must exist.


Houdini’s shaders are specific to particular renderers. Rendering with a different renderer will require you to use different shaders on your objects. However, you can switch shaders based on the renderer.

How to

To...Do this

Create a new render node

Choose Render ▸ Create Render Node from the main menu.

Edit an existing render node

Choose Render ▸ Edit Render Node from the main menu.

Start a render

  • In the render node’s parameter editor, click the Render button.


Show the render network

Click the first segment of the path control at the top of a network editor and choose Other networks ▸ out.

Make one render node depend on the output of another

Wire the nodes together to create dependency relationships. See render dependencies.

Prevent a render node/branch from rendering

Use the Bypass flag or Lock flag (see render node flags/buttons below).

Tips and notes

  • Bypassing or locking a subnetwork will prevent any of the ROPs inside from rendering.

  • You can still force a bypassed or locked render node to render using the “Render All Bypassed Nodes” and “Render All Locked Nodes” options in the render control window.


Mantra user guide



Next steps


Other renderers