How To Change Reder Background In Houdini

Overview

Mantra is the highly advanced renderer included with Houdini. It is a multi-paradigm renderer, implementing scanline, raytracing, and physically-based rendering. Y'all should use the physically based rendering engine unless you have a adept reason to use another engine. Mantra has deep integration with Houdini, such every bit highly efficient rendering of packed primitives and volumes.

You can implement Mantra shaders using a VOP network or by writing a program in the VEX shading language.

Tip

Houdini also lets yous integrate third-political party renderers such equally RenderMan™, Arnold™, Redshift™, OctaneRender™, V-Ray™, mental ray™, and Maxwell™.

In general, rendering in Houdini uses a camera defining the viewpoint to render from, lights to illuminate the scene, and a return node representing the renderer and return settings to employ. However, you can however make preview renders using the current view, a headlight, and default render settings.

Preview rendering

The Render view, sometimes called the IPR (interactive photorealistic return) view, shows a rendered image that updates as you move lights and objects, change parameters, and and so on.

The Render region tool lets you lot outline a rectangle in the 3D viewer that acts like a mini render view. It renders that function of the view and updates the rendered rectangle as you change things.

Starting a final render

Yous tin can do most of your work in the Render view to meet an interactive updating render. This lets you assign materials and change return node and shader node parameters and see the results equally you piece of work.

When you desire to practise a final return:

In the return node'south parameter editor, click Return to Disk or Return to Mplay.

Cull Render ▸ Kickoff Renderer ▸ return node in the master menus.

Click the Launch render button in the toolbox on the left side of the viewer.

Right-click the button and choose a return output node to render, or View: Mantra to render the current view.

Afterwards you set the default render node in the menu, clicking the icon will use that render node. The initial default renders the current view.

Yous can script rendering using the render HScript control or the hou.RopNode interface in Python.

Setting up a render node

Add together lights to the scene and create a camera. See lights and cameras. If you don't have lights in the scene the return will come up out black.

To...	Exercise this
Create a render node	In the main menus, choose Return ▸ Create Render Node ▸ Mantra. Mantra is Houdini'south powerful built-in renderer. If y'all only have one camera in the scene, it is automatically chosen as the camera the new return node volition render from.
Edit the parameters of a render node	You can edit a return node's parameters and render properties in the parameter editor. Choose Render ▸ Edit Render Node ▸ `node proper name` to open a floating parameter editor for the render node. or In the network editor, go to the "Outputs" (`/out`) network. (Click the first segment of the path at the height of the network editor pane and choose `out`.) Select the node to open it in the parameter editor pane. For help on the render parameters, see the Mantra node assistance.
Set up whether to return a single frame or animation	The Valid Frame Range carte du jour controls whether this render node renders single frames or sequences (animations). Cull Any frame to return single frames. Choose Frame range to render a sequence. If y'all are rendering a sequence, make sure to include the frame number variable `$F` in the filename, otherwise the renderer will overwrite e'er frame with the same name. Meet expressions in filenames.
Set the output size/resolution	The size of the rendered image is controlled by a parameter on the camera. Select the photographic camera object and set the View ▸ Resolution parameter in the parameter editor. (For help on the other camera parameters, see the Camera node assistance.) or Yous tin can override the camera's paradigm size parameters in the render node by turning on Properties ▸ Output ▸ Override camera resolution.
Set the camera to render from	Click the Main tab and edit the Camera field. (Click the button to the right of the field to cull the photographic camera from a list.)

Controlling object visibility

To...	Do this
Make an object visible or invisible in the viewer	Plow the object's Display flag on or off.
Make an object totally invisible in the render	In the object'south parameter editor, click the Render tab and turn off Renderable.
Make an object invisible but cast reflections/shadows	In the object'south parameter editor, click the Return tab and plough Renderable off and Phantom on.
Use unlike geometry for viewport display and rendering	In the geometry network of an object, yous tin can set the display and render flags on different nodes to point different geometry output for display and rendering. This is useful to replace depression-resolution proxy geometry for display with high-resolution geometry for rendering.
Instance geometry onto points at render time	See betoken instancing.
Prevent an object from reflecting	Edit the Render ▸ Shading ▸ Reflection Mask parameter on the reflective object.

Tips

You can return a deep camera map to get a "2.5-D" image with depth information. (When rendering .pic or .rat, the depth data is embedded in the file. When rendering .exr it is saved to an additional output file.) The depth information lets you composite rendered images in 3D.
The Switcher object is a special photographic camera that lets you animate switching between the viewpoints of several different cameras.
Click the Controls button on the parameter editor of the render node to open up the Render Command window. This window lets you temporarily override render parameters (such as the frame range, or whether to return dependencies) per-render, without having to edit the parameters on the node (and remember to alter them back).
1. In the main menu, choose Return ▸ Edit Render Node ▸ render node .
2. Click the Render Control button on the parameter editor of the render node.
3. Gear up the Frame Range option in the Output Overrides section.
Y'all can besides override the rendering of dependencies from the window. See how to fix up a render node and the Return Control window for more information.