What is True Caustics?

It is a set of high quality 2k and 4k textures for use in underwater 3D renders. With 3 different light scenarios, each with 2 depth variations and dispersed and grayscale versions, they are a great way to add extra spice to any underwater render. All the textures are fully simulated with ray tracing to get a level of quality unparalleled by procedural techniques.

Seamless and Looping

All True Caustic textures are seamless for infinite tile ability and loop for those long underwater shots.

Easy to use

To use True Caustics, simply make a point or area light, turn on use nodes, and add the image sequence of your choosing to the light. You can then adjust it to your liking, I suggest using a gamma node to do so.

Do note that this method only works in Cycles as eevee does not support texture projection for lights like cycles does. In eevee, it is better to use the mesh based approach provided in the $10 tier. In Legacy eevee, you can use the textures as gobos with transparent planes decently well, but unfortunately it does not look very good at all in eevee next, which is currently just a limitation of the engine. 

Eevee Usage

In True Caustics+ there is a blend file called 'Eevee Caustics' which is the best way to make caustics in Eevee, and uses a mesh based approach as seen below.

The file comes with the caustics object marked as an asset for use in other files via the asset browser. Do be warned that this method is quite slow to calculate  and it is recommended to keep the resolution low (around 10).

Installation Guide

True Caustics comes in segmented zip files to avoid file size caps. To unzip them, simply have them all in one folder and using winrar or 7zip, unzip the main '.zip' file for whatever texture set you're downloading. This will automatically unzip all of the segmented files into one folder, and you can then delete the zip parts. This GIF shows how to do it if you're confused (I cancel the unzip early for demonstration purposes).