Cavity is an effect in Blender that exaggerates the ridges and valleys of a 3D model. It makes these features more visible in the 3D viewport. Cavity is generally not rendered, but it can be using the Workbench render engine.


Here’s everything there is to know about the cavity settings in Blender.
Enabling Cavity in the Blender 3D Viewport
Cavity can be enabled for an entire Blender scene, not for individual objects. It is only visible in Solid Mode (not look dev or render preview modes). To enable cavity, we need to be in Solid Mode and expand the shading options dropdown arrow next to the viewport shading menu.

The checkbox to turn on cavity is near the bottom of the solid view options. Check the box to activate cavity.

Here’s a quick video from my YouTube channel showing what Cavity does and how to turn it on in Blender version 4.3…
Cavity Settings
In the viewport shading options menu, next to the cavity checkbox, there are three settings to adjust how the Cavity effect is displayed.
Cavity Type
There are two Cavity Type options for how the cavity effect is displayed in the Blender viewport. We can choose to use one or both of these:

World Space
The cavity can be computed in world space, which is useful for larger scale occlusion. Here’s an example:

Screen
The “Screen” Type is a curvature-based effect which is useful for making fine details more visible. Here is an example of screen cavity type:

Both
We can have both World and Screen types activated at the same time to achieve both effects simultaneously. Below is an example:

Ridge and Valley Strength Settings
Below the cavity checkbox and cavity type dropdown box are settings to adjust the strength of ridges and valleys in the cavity effect. There are separate settings for the world space effect and the screen space effect.

Only the settings for the selected type will display. If you choose “Both” for the cavity type, both world and screen settings will appear.
We can adjust the strength of the cavity effect for both ridges and valleys of objects in the viewport. The ridges setting is how exaggerated outward protrusions (ridges) will be. The valley setting is how exaggerated the inward (valleys) of objects will be.
Higher values cause a more dramatic effect. Lower values reduce the effect. By default, all values are set to one.
How to Render the Cavity Effect
The cavity effect can not be rendered in Cycles or Eevee. It’s not a realistic effect and is intended for the 3D viewport.
However, if you use the Workbench render engine, you can render with the cavity effect enabled. The Workbench render engine is the engine used for the 3D viewport’s solid view. It’s essentially exactly what you see in the 3D viewport while using solid mode.
Conclusion
Cavity is a popular effect in Blender which is not turned on by default. It exaggerates ridges and valleys in the 3D viewport. It can be turned on for an entire scene, but not for individual objects. There are a handful of settings to adjust the look of the cavity effect.
I hope this was helpful. Please see my YouTube channel for video tutorials and STAY CREATIVE!