There were a few requests to step folks through how to create and use 'Face Models' that have been enabled by the ReActor extension since version 0.5.1.
Note of caution:
ReActor is a face-swapping extension that makes it really easy to replace faces in a target image. It must therefore be used responsibly. Using it to swap-in faces of real persons (e.g., celebrities, politicians, etc.) could be illegal depending upon your jurisdiction, and is against the ToS for civitai. You have been warned.
Prerequisites:
Automatic 1111 setup with ReActor extension: https://github.com/Gourieff/sd-webui-reactor
Base image from which you want to create the face model. In our case we'll be using this AI generated female face that I am going to christen 'Mythika'
Creation of Face Model
Open ReActor drop-down on txt2img tab (Tip: A1111 arranges and processes extensions alphabetically)
Within the extension, go to the 'Tools' tab
Drag and drop image with the base face in it. Note that the image must have the face of just one person otherwise the result is unpredictable.
Give a name to your face model in the 'Face Model Name' section. In our case, will call it 'Mythika'
Press 'Build and Save'
That's it! Your face model should be saved to you '...\models\reactor\faces\' folder as a .safetensors file. So in our case it's Face model has been saved as '...\models\reactor\faces\Mythika.safetensors'
Using the Face Model
You can use the face models in the txt2img, img2img, and extras tabs
In the txt2img create the prompt and negative prompt as you normally would
To use the face model, make sure that the 'ReActor' extension is active (selected) using the checkbox at the left top of the dropdown.
In the Main tab under the extension, under 'Select Source' choose 'Face model' as the radio button selection.
From the drop-down list on the right select your new face model (note that if you just created the model, it may not show up in the list. In that case, press the 'refresh' button to the right of the drop-down)
Press generate. The final image should have the face swapped in. See the original vs the swap-in below (original image on left, swapped in image on the right)
Using Face Models downloaded from CivitAI
In case you're using a face model like the ones I have posted on this site, for example:
then:
Download the file (it's a zip because CivitAI doesn't allow you to upload any other format in 'Other' models
Unzip it
Copy the .safetensors file from the zip to your '...\models\reactor\faces\' folder
Refresh and use as described in the 'Using the Face Model' section above.
Parting notes
Using ReActor is a really great way of getting consistent faces in multiple images. This said, there are a few upsides and downsides as described below.
Upside of face models:
Create once, use any number of times
Efficiency (you no longer need to have to select a source image, tag faces, etc.)
Useful if you're naming virtual characters
Downside:
You're stuck with one 'look' of the character - if s/he looked different in different ages for example, then that requires you to create different face models
Output is not as good as a trained LoRA. This is generally true about the ReActor extension. At the end of the day, ReActor is a face-swapping tool. The output is therefore more airbrushed.