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Table of Contents

This page gives some basic information on IPR within Houdini as well as on how to incorporate the interactive renderer into your workflow.



V-Ray Interactive Production Rendering (IPR) is an interactive rendering engine that can utilize both CPU and GPU hardware acceleration to see updates to the rendered image in real time as objects, lights, and materials are edited within the scene.

For more information on the settings available for IPR, please see the Export Tab page and the IPR Tab page.



IPR Workflow within the VFB

Before starting an IPR, make sure a camera is set. You can set several cameras and then switch between them.


1. Create ROP

Create a V-Ray Renderer node and a V-Ray Renderer IPR node. This can be done in several ways:

  • ||out Network|| > V-Ray Renderer; ||out Network|| > V-Ray Renderer IPR
  • Go to Render menu > Create Render node > V-Ray

For more information, see the Rendering page.


2. Configure ROP

Configure the render settings within the Export Tab and the IPR Tab of the V-Ray Renderer node. To navigate to the specific tabs, do one of the following:

  • ||out Network|| > V-Ray Renderer node > Export tab and ||out Network|| > V-Ray Renderer node > Renderer tab > IPR tab
  • Go to Render menu > Edit Render Node

  • Go to V-Ray menu > Render Settings

  • In the V-Ray Shelf, click the ROP Parm button.

You can have multiple V-Ray Renderer and V-Ray Renderer IPR nodes with different settings in a scene.




3. Render

Start the IPR in one of the following ways:

  • In the V-Ray Shelf, click the IPR (VFB) button. This initiates a render process in the VFB.
  • Go to V-Ray menu > Show VFB and select a V-Ray ROP. Then, in the VFB, click the Start interactive rendering button.

  • In the V-Ray Shelf, click the Show VFB button. Then in the VFB, click the Start interactive rendering button.

If vray/vray_ipr nodes aren't created in the out Network, clicking the IPR (VFB) button on the V-Ray Shelf creates a vray node and starts interactive rendering in the VFB. If necessary, configure the render settings as explained above.

Clicking the Render button or the Show VFB button, also automatically creates a vray node if none has been previously created.




Switching Camera Views

You can have multiple cameras in a scene. Each camera may be configured to use specific parameters and show the scene from a different angle (or just part of the scene). To select a camera, open the VFB and Shift+Left-click on the Start interactive rendering button.





Switching Render Settings

You can have multiple IPR settings in a scene. To select different settings, Shift+Left-click on any of the IPR (VFB) or ROP Parm buttons in the V-Ray Shelf and select the settings you want.





VFB Render Region

In addition, the IPR rendering refreshes whenever the Region Render area is redrawn.



Original Region Render


 IPR refreshes as the Region Render area is altered.


IPR Workflow in the Viewport

V-Ray for Houdini supports interactive rendering in Houdini's Render View. To benefit from this feature, go to Render View > Render button.

Note that the Use V-Ray Frame Buffer option must be disabled.

You can also use the Render Region option, if you go to Scene View (viewport).


Interactive Rendering in Houdini's Render View


Interactive Rendering using Houdini's Render Region in the Scene View.