Baking Physics Simulations in Blender: Cache and Render Guide

What will you learn in this guide?

Baking a physics simulation in Blender means storing the calculated results so they can be reused during subsequent playback. The first time an animation plays, the simulation is temporarily cached in memory; on later runs, the results can be read from that cache for faster playback. Baking turns this temporary result into a preserved cache.

This guide explains how to prepare a bake before rendering, name caches, store them on disk, and use an external cache. The Blender 5.2 LTS Manual section cited in the sources covers Geometry Nodes simulations. The steps here are based on the page about baking physics simulations; the settings for these two topics should not be assumed to be the same.

Requirements and version notes

Blender is required. The physics baking page cited in the sources does not specify which Blender version it applies to, so the instructions below do not describe menu locations or options specific to a particular version. The sources also do not specify whether an account is required, so no requirement can be stated on that point.

Before baking, it is helpful to make sure the scene’s simulation is working, review the start and end frames, and decide where the cache will be stored. According to the source, the simulation is calculated only between the Start and End frames in the cache settings. If you need a simulation longer than the default frame range, adjust the End value accordingly.

Step by step: baking a simulation

1. Play the simulation and check the temporary result. When the animation plays, Blender temporarily stores the simulation result in memory. This data can be reused during subsequent playback. Before baking, check that the result behaves as expected and that the frame range to be calculated is correct. The temporary cache may be cleared when objects or settings change, or when the frame changes; it should not be treated as a permanent result.

2. Set the Start and End frames. In the cache settings, Start defines the frame where the simulation begins, and End defines where it stops. Make sure the simulation covers the entire desired range. Frames outside that range will not be calculated, even when you bake. The source states that the simulation is calculated only on positive frames between these two values.

3. Name each cache if there is more than one. Blender can keep multiple caches for the same physics object. You can name an entry by double-clicking it in the cache list. If an object has multiple physics systems and unnamed caches, file name collisions can occur, potentially causing cache files to be lost. That is why it is important to name each cache clearly when using more than one.

4. Choose how to store the cache. If Disk Cache is disabled, the baked cache is stored inside the blend file. If Disk Cache is enabled, the data is written separately to a folder named blendcache_[filename] next to the blend file. The blend file must already have been saved. If you plan to move or share the files with the project, consider in advance whether the selected storage method fits your workflow.

5. Set an external cache path if needed. The External option lets Blender read a cache from the specified file path. The name in the cache list and the Index value must exactly match the names of the external cache files. The files use the format name_frame_index.bphys; Index is the number in the last two digits of the file name. The path should point to the folder containing the cache files.

6. Review the Cache Step value as needed. This value determines how often simulation data is stored. For some physics systems, a Cache Step greater than one allows intermediate frames to be interpolated instead of calculated, reducing the size of the cache. However, the result may differ from the original simulation, and this option may not be available for every physics system. Do not overlook the risk of changing the result in an effort to reduce file size.

7. Start the bake. You must be in Object Mode to bake. Once baking starts, Blender may appear unresponsive during most bake operations; progress is shown as a number on the cursor. Wait for the operation to finish. A baked cache is preserved, and the simulation settings cannot be changed.

8. Consider baking all simulations in the scene together. Bake All Dynamics bakes all physics systems in the scene, including different types of physics systems. It can be used for complex setups where different physics types interact. Calculate to Frame is available to bake only up to the current frame; this is limited by the End value in the cache.

9. Verify the baked result before rendering. The Blender Manual generally recommends baking physics simulations before rendering. Baking can reduce the need to recalculate the simulation before every render and help keep the result consistent each time. Play back the results to check them before rendering. If you need to adjust the settings, clear the baked frames with Delete Bake; you can change the simulation settings after doing so.

Common mistakes

One of the most common issues is setting the simulation’s End frame earlier than the end of the intended animation. Since baking only calculates the specified frame range, you should not expect a longer result. Another risk is leaving multiple caches on the same object unnamed: file names can collide, and cache files may be lost.

When using an external cache, selecting the folder path alone is not enough; the cache name and Index value must also match the file name. Increasing Cache Step is not always a harmless way to reduce file size: intermediate frames may be interpolated, and the result may change. Finally, being unable to change settings while a cache is baked is not an error—it is how bake preservation works. Use Delete Bake before making changes.

Next steps

First, test playback and baking over a short frame range, then move on to the intended Start and End values. If the scene contains multiple physics systems, give each cache a separate, descriptive name; when different systems interact, consider using Bake All Dynamics. If the cache needs to travel with the project file, check whether the disk cache folder next to the blend file is included in your workflow.

Sources and license

The information on Blender Manual’s “Baking Physics Simulations” page has been adapted and summarized in Turkish. Blender Manual is licensed under CC BY-SA 4.0. The “Simulation Nodes” page in the Blender 5.2 LTS Manual was used to distinguish the scope; the baking steps in this guide are not taken from that page.