---
title: "Resumable Rendering"
canonical: "https://documentation.chaos.com/space/VBLD/910819616/Resumable%20Rendering"
format: markdown
---
This page describes the steps to use resumable rendering in V-Ray for Blender.


## **Overview**

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Resumable rendering allows you to pause and finish renders at different times. This feature provides ease of mind in cases where the render suddenly stops due to external forces, such as a power failure or a job being bumped on a render farm. It can also be used for your convenience to pause the render and later start from where you left off.

> ⚠️ Making changes between resumable rendering sessions results in an error. In such cases, the generated resumable files must be manually deleted before restarting the rendering process.

Resumable renders are possible with both Bucket and Progressive image sampling modes.

With Bucket rendering, an additional *.vrimg* is written to temporarily store the data from the completed buckets. When you resume rendering, V-Ray reads the *.vrimg* file to determine which buckets still need to be rendered and continues to calculate what is left to complete the image. Another advantage of this feature is that the light cache is saved within the partial image file so it doesn't need to be recalculated when the render resumes.

When rendering in the Progressive image sampling mode, the state of the render is saved to an additional resumable *.vrprog* file in a similar way to the .vrimg for Bucket rendering. Enabling **Autosave Interval (min.)** in the [Image Output rollout](https://docs-chaos.atlassian.net/wiki/spaces/VBLD/pages/733249591) (by setting it higher than 0) is highly recommended for Progressive renders, so V-Ray can write out the *.vrprog* files during rendering in case the process is unintentionally stopped. Setting the Autosave Interval value too low (below a couple of minutes, for example) can slow down the render process.

If V-Ray finds a *.vrprog* file or a partially completed *.vrimg* file for the current frame, the rendering resumes from where it left off. If not, V-Ray starts a new render, and saves a resumable file.