Sometime it might happen that the model you are using crashes when rendering due to Out of Memory errors. One of the cause might be that the textures that are used by the model have a bigger resolution than what’s needed (for instance 4K instead of 2K). In this quick tutorial we go through a quick way to batch downgrade the textures.

Requirements

• This tutorial is for Windows, but a similar approach can be used on macOS and Linux using the Terminal instead.
• ImageMagick (free tool to batch modify images from any terminal). For instance, you can download the Windows ImageMagick from this link.

Preparing the Folder

After installing ImageMagick, we can open the folder where the textures are located. Since Blender tries to search for textures in the textures folder located in the same folder as the .blend file, I suggest you to do the following.

• Duplicate the folder with the textures.
• Rename the folder you created with another name, e.g., textures_4k.
• Downgrade the textures in the textures folder.

This way you have a backup in case you’ll make some mistakes in the following steps. Plus, you can quickly switch between 4K and 2K textures just renaming the folders and restarting Blender.

Downgrading Textures

Warning: the procedure will overwrite all the textures in the folder where you’ll lunch the following commands. Thus if you don’t want to lose the original textures, make a backup!

To convert the textures, enter the texture folder. Click on the path bar on top, type “cmd” (as in the image) and press Enter.

A command prompt window should appear. Write the command:

magick mogrify -resize 50% *.png

And redo this for all the image formats you have in your folder (usually jpg or tiff).

And that’s it, with this you can convert all your images from 4K to 2K. Change the 50% if you need a more drastic decrease.

Note: you can also choose the textures destination folder if you do not want to overwrite the textures with –path and writing the absolute or relative path of your new folder.

magick mogrify -resize 50% -path ../new-folder *.png

Bonus

With ImageMagick you can do a lot of cool batch operations! For instance, you can also convert all the images from one format to another with a simple command:

magick mogrify -format png *.tiff

Or combine different greyscale images into an RGB one with

magick convert image1.png image2.png image3.png -combine result_image.png

Check the documentation for the list of all cool features of this software.