Official [2020.1] New Feature - Baked Light Cookies

An example of baked fake caustics achieved using baked light cookies. Imagery courtesy of David Llewelyn.

Overview
This feature was developed by Uygar Kalem (@uy3d).

Using modelled geometry is one of the methods to change the way the light looks. Getting accurate and clean results using such method would need a lot of samples. This is where light cookies come into play. They allow users to change light's appearance and intensity. With their help, users can simulate many different lighting effects. Such effects include caustics, soft shadows, light shapes, and others. This practice is very common in games and architectural visualizations. Before this feature was only available for realtime and mixed lights. We now support baked lights as well.

Baked light cookies have no runtime cost and are very efficient to render. As an added benefit, they also affect indirect global illumination. This is a key factor when striving to achieve realism in baked lighting scenes.

We support both grayscale and RGB textures. RGB textures allow for colored cookie effects. Grayscale textures act as a simple mask. Keep in mind that point lights need a cubemap texture in order for cookies to work. All other lights need 2D cookie textures.

Setup instructions
Baked cookies support is disabled for upgraded Unity projects to maintain legacy behavior. In order to enable it, navigate to Edit > Project Settings > Editor and make sure that Enable baked cookies support flag is checked. Newly created projects will have this flag checked by default.



Select a light in the scene. In the Inspector, unfold the Emission header. Cookie texture field is located there.


Here are couple of things to keep in mind when importing cookie textures in different render pipelines:

• In HDRP, set Texture Type field to Default. Set Texture Shape to 2D if the texture is a 2D map. For cubemaps, set Texture Shape to Cube.
• In Built-in RP, set Texture Type field to Cookie. Set Light Type property to Spot if the texture is a 2D map. For cubemaps, set Light Type property to Point.

Unity's texture importer will extract the cookie mask from the alpha channel. For colored cookies make sure the texture contains no alpha channel.

Additional information
For more information on light cookies, please refer to the following pages:

• Create high-quality light fixtures in Unity - https://blogs.unity3d.com/2019/02/05/create-high-quality-light-fixtures-in-unity/
• Unity Manual - https://docs.unity3d.com/Manual/Cookies.html
• HDRP Manual - https://docs.unity3d.com/Packages/c...gh-definition@8.0/manual/Light-Component.html

Please keep in mind that is feature is currently available in Built-in and High Definition Render Pipelines. Support for Universal Render Pipeline will follow at a later stage.

Feature access & feedback
You can get access to the feature by downloading the latest 2020.1 alpha build via the Unity Hub, or via this link - https://unity3d.com/alpha/2020.1a#downloads. We are looking forward to hearing your feedback!

 

The IES support will sit on top of this feature. Work is underway on an IES importer. Once that is done we can connect the dots.

 

This setting is a guard to ensure legacy behavior. By default support will be enabled for new projects (the new scene templates are being updated currently). Unless you're upgrading an old project and want to start using cookies, you shouldn't even have to know about this setting.

 

You'll have to use the soon to be released HDRP version 8.1 for baked cookie support.

 

Latest probably not. There'll be a proper 8.1 release and it should show up in the package manager.

 

PSA: @JenniferNordwall has made some UI usability improvements to this feature. The checkbox in the Project Settings window has been renamed from Disable cookies support to Enable baked cookies support.

We will now also show a warning when assigning a cookie to baked light when baked cookie support is not enabled. Same goes for mixed lights.

This change will land soon in the latest 2020.2 alpha. 2020.1 backport is on its way.

 

Baked and realtime cookies were implemented by the URP team. I would suggest asking in the URP sub-forum. Better yet, submit a bug report and they will take a look.

 

I believe the location of the cookie property depends on which render pipeline you are using. If you still haven't found it, leave a screenshot of what you are seeing when you select a light