Creating realistic glass in Eevee is difficult due to the fact that settings are spread out in a number of places and not having good defaults. I also added a custom node to control the direction of refraction and highlights.
Eevee has some limitation with multiple objects, thickness and quality of refraction. The goal here is to have good enough quality for realistic rendering.
Here is example of Cycles rendering of glass from a scene from Definitive Interiors course from @chippwalters.
Using Eevee with a typical Eevee glass shader.
Using Eevee with my custom Eevee glass shader with correct settings.
With this new shader and settings we get refraction through glass and highlights. The thickness of refraction at the base of the glass is much darker. All these improvements matches the Cycle render much closer.
Another Eevee render from a converted Evermotion scene using my custom shader with correct settings.
Tips for creating a realistic Glass rendering with Eevee.
- Make cycles render to better visualize glass refraction and highlights to use as a reference.
- Screen Space Reflection Settings: enable Refraction.
- Screen Space Reflection Settings: lower thickness to “0.1m”.
- Screen Space Reflection Settings: trace precision to “1.0”.
- Material Settings: Blender Mode to “Alpha Hashed”.
- Material Settings: Transparent Shadows to “Opaque”.
- Material Settings: Screen Space Reflection to enable.
- Material Settings: Refraction Depth to “0”.
- Create a Mix Shader node with Fresnel, Glass BSDF and Glossy BSDF. See node picture below:
- The Fresnel node control reflection a good range is between 0.5 to 3.0. It is going to vary based depending on the size and thickness of glass. Make sure to start low at 0.5 and increase until the reflection is correct.
- The Glass BSDF controls base glass color and refraction direction with IOR. See that is below 1.0 to reverse the direction of refraction a typical value of 0.95.
- The Glossy BSDF controls the highlights quality. Base color usually all white and can go above 1. A good value is 1.
- Multiple Glass Objects: For the glass objects behind change the Material Settings: Screen Space Refraction to off.
This is a good starting base of Eevee settings for glass. Adjustment may be need depending on the glass type, lighting and scene content.