Rendering Setting up a render node

In Houdini, all rendering is done through a render node. Each rendering program Houdini supports has its own node type, and you can have multiple render nodes of any type representing different render scenarios, such as different quality settings (e.g. test vs. final render), render passes, sub-portions of a scene, and so on.

Once you have lights you can perform test renders of the current view without having to create a camera or render node, but for reproduceable results you will want to create a render node and at least one camera.

1. Add lights to the scene and create a camera. See lights and cameras. If you don’t have lights in the scene the render will come out black.

2. In the main menus, choose Render > Create Render Node > Mantra. Mantra is Houdini’s powerful built-in renderer.

   • You can edit the parameters of the renderer in the parameter editor. If you only have one camera in the scene, it is automatically chosen as the camera the new render node will render from.

     Otherwise, to choose which camera to render from, click the Main tab in the output driver node’s parameter editor and edit the Camera field Click the button to the right of the field to choose the camera from a list.

   • To choose where to render the image to, click the Properties tab, then click the Output subtab, then edit the Output picture parameter.

     A value of ip will render directly into the MPlay image viewer. Any other value is taken to be a filename.

   • The Valid Frame Range menu controls whether this render node renders single frames or sequences (animations). Choose Any frame to render single frames. Choose Frame range to render a sequence.

     If you are rendering a sequence, make sure to include the frame number variable $F in the filename, otherwise the renderer will overwrite ever frame with the same name. See expressions in filenames.

   For help on the other render parameters, see the Mantra node help.

3. The size of the rendered image is controlled by a parameter on the camera. Select the camera object, and in the parameter editor click the View tab and set the Resolution parameter.

   For help on the other camera parameters, see the Camera node help.

4. Click the Launch render button in the toolbox on the left side of the viewer to render the scene. See rendering an image for more information.

• Choose Render > Edit Render Node > node name to open a floating parameter editor for the render node.

• To view the render nodes in the network editor, click the first segment of the path at the top of the network editor pane and choose out.

  

• The Switcher is a special camera that lets you animate switching between the viewpoints of several different cameras.

• Click the Render Control button on the parameter editor of the render node to open the Render Control window. This window lets you temporarily override render parameters (such as the frame range, or whether to render dependencies) per-render, without having to edit the parameters on the node (and remember to change them back).